vinum -- Logical Volume Manager control program
vinum [command] [-options]
attach plex volume [rename]
attach subdisk plex [offset] [rename]
Attach a plex to a volume, or a subdisk to a plex.
checkparity plex [-f] [-v]
Check the parity blocks of a RAID-4 or RAID-5 plex.
concat [-f] [-n name] [-v] drives
Create a concatenated volume from the specified drives.
create [-f] description-file
Create a volume as described in description-file.
debug Cause the volume manager to enter the kernel debugger.
debug flags
Set debugging flags.
detach [-f] [plex | subdisk]
Detach a plex or subdisk from the volume or plex to which it is
attached.
dumpconfig [drive ...]
List the configuration information stored on the specified
drives, or all drives in the system if no drive names are specified.
info [-v] [-V]
List information about volume manager state.
init [-S size] [-w] plex | subdisk
Initialize the contents of a subdisk or all the subdisks of a
plex to all zeros.
label volume
Create a volume label.
l | list [-r] [-s] [-v] [-V] [volume | plex | subdisk]
List information about specified objects.
ld [-r] [-s] [-v] [-V] [volume]
List information about drives.
ls [-r] [-s] [-v] [-V] [subdisk]
List information about subdisks.
lp [-r] [-s] [-v] [-V] [plex]
List information about plexes.
lv [-r] [-s] [-v] [-V] [volume]
List information about volumes.
makedev
Remake the device nodes in /dev/vinum.
mirror [-f] [-n name] [-s] [-v] drives
Create a mirrored volume from the specified drives.
move | mv -f drive object ...
Move the object(s) to the specified drive.
printconfig [file]
Write a copy of the current configuration to file.
quit Exit the vinum utility when running in interactive mode. Normally
this would be done by entering the EOF character.
read disk ...
Read the vinum configuration from the specified disks.
rename [-r] [drive | subdisk | plex | volume] newname
Change the name of the specified object.
rebuildparity plex [-f] [-v] [-V]
Rebuild the parity blocks of a RAID-4 or RAID-5 plex.
resetconfig
Reset the complete vinum configuration.
resetstats [-r] [volume | plex | subdisk]
Reset statistics counters for the specified objects, or for all
objects if none are specified.
rm [-f] [-r] volume | plex | subdisk
Remove an object.
saveconfig
Save vinum configuration to disk after configuration failures.
setdaemon [value]
Set daemon configuration.
setstate state [volume | plex | subdisk | drive]
Set state without influencing other objects, for diagnostic purposes
only.
start Read configuration from all vinum drives.
start [-i interval] [-S size] [-w] volume | plex | subdisk
Allow the system to access the objects.
stop [-f] [volume | plex | subdisk]
Terminate access to the objects, or stop vinum if no parameters
are specified.
stripe [-f] [-n name] [-v] drives
Create a striped volume from the specified drives.
The vinum utility communicates with the kernel component of the Vinum
logical volume manager. It is designed either for interactive use, when
started without command line arguments, or to execute a single command if
the command is supplied on the command line. In interactive mode, vinum
maintains a command line history.
vinum commands may optionally be followed by an option. Any of the following
options may be specified with any command, but in some cases the
options are ignored. For example, the stop command ignores the -v and -V
options.
-f The -f (``force'') option overrides safety checks. Use with
extreme care. This option is for emergency use only. For example,
the command
rm -f myvolume
removes myvolume even if it is open. Any subsequent access to
the volume will almost certainly cause a panic.
-i millisecs
When performing the init and start commands, wait millisecs milliseconds
between copying each block. This lowers the load on
the system.
-n name
Use the -n option to specify a volume name to the simplified configuration
commands concat, mirror and stripe.
-r The -r (``recursive'') option is used by the list commands to
display information not only about the specified objects, but
also about subordinate objects. For example, in conjunction with
the lv command, the -r option will also show information about
the plexes and subdisks belonging to the volume.
-s The -s (``statistics'') option is used by the list commands to
display statistical information. The mirror command also uses
this option to specify that it should create striped plexes.
-S size
The -S option specifies the transfer size for the init and start
commands.
-v The -v (``verbose'') option can be used to request more detailed
information.
-V The -V (``Very verbose'') option can be used to request more
detailed information than the -v option provides.
-w The -w (``wait'') option tells vinum to wait for completion of
commands which normally run in the background, such as init.
vinum commands perform the following functions:
attach plex volume [rename]
attach subdisk plex [offset] [rename]
vinum attach inserts the specified plex or subdisk in a volume or
plex. In the case of a subdisk, an offset in the plex may be
specified. If it is not, the subdisk will be attached at the
first possible location. After attaching a plex to a non-empty
volume, vinum reintegrates the plex.
If the keyword rename is specified, vinum renames the object (and
in the case of a plex, any subordinate subdisks) to fit in with
the default vinum naming convention. To rename the object to any
other name, use the rename command.
A number of considerations apply to attaching subdisks:
+o Subdisks can normally only be attached to concatenated
plexes.
+o If a striped or RAID-5 plex is missing a subdisk (for example
after drive failure), it should be replaced by a subdisk of
the same size only.
+o In order to add further subdisks to a striped or RAID-5 plex,
use the -f (force) option. This will corrupt the data in the
plex.
+o For concatenated plexes, the offset parameter specifies the
offset in blocks from the beginning of the plex. For striped
and RAID-5 plexes, it specifies the offset of the first block
of the subdisk: in other words, the offset is the numerical
position of the subdisk multiplied by the stripe size. For
example, in a plex with stripe size 271k, the first subdisk
will have offset 0, the second offset 271k, the third 542k,
etc. This calculation ignores parity blocks in RAID-5
plexes.
checkparity plex [-f] [-v]
Check the parity blocks on the specified RAID-4 or RAID-5 plex.
This operation maintains a pointer in the plex, so it can be
stopped and later restarted from the same position if desired.
In addition, this pointer is used by the rebuildparity command,
so rebuilding the parity blocks need only start at the location
where the first parity problem has been detected.
If the -f flag is specified, checkparity starts checking at the
beginning of the plex. If the -v flag is specified, checkparity
prints a running progress report.
concat [-f] [-n name] [-v] drives
The concat command provides a simplified alternative to the
create command for creating volumes with a single concatenated
plex. The largest contiguous space available on each drive is
used to create the subdisks for the plexes.
Normally, the concat command creates an arbitrary name for the
volume and its components. The name is composed of the text
``vinum'' and a small integer, for example ``vinum3''. You can
override this with the -n name option, which assigns the name
specified to the volume. The plexes and subdisks are named after
the volume in the default manner.
There is no choice of name for the drives. If the drives have
already been initialized as vinum drives, the name remains. Otherwise
the drives are given names starting with the text
``vinumdrive'' and a small integer, for example ``vinumdrive7''.
As with the create command, the -f option can be used to specify
that a previous name should be overwritten. The -v is used to
specify verbose output.
See the section SIMPLIFIED CONFIGURATION below for some examples
of this command.
create [-f] description-file
vinum create is used to create any object. In view of the relatively
complicated relationship and the potential dangers
involved in creating a vinum object, there is no interactive
interface to this function. If you do not specify a file name,
vinum starts an editor on a temporary file. If the environment
variable EDITOR is set, vinum starts this editor. If not, it
defaults to vi. See the section CONFIGURATION FILE below for
more information on the format of this file.
Note that the vinum create function is additive: if you run it
multiple times, you will create multiple copies of all unnamed
objects.
Normally the create command will not change the names of existing
vinum drives, in order to avoid accidentally erasing them. The
correct way to dispose of no longer wanted vinum drives is to
reset the configuration with the resetconfig command. In some
cases, however, it may be necessary to create new data on vinum
drives which can no longer be started. In this case, use the
create -f command.
debug vinum debug, without any arguments, is used to enter the remote
kernel debugger. It is only activated if vinum is built with the
VINUMDEBUG option. This option will stop the execution of the
operating system until the kernel debugger is exited. If remote
debugging is set and there is no remote connection for a kernel
debugger, it will be necessary to reset the system and reboot in
order to leave the debugger.
debug flags
Set a bit mask of internal debugging flags. These will change
without warning as the product matures; to be certain, read the
header file <sys/dev/vinumvar.h>. The bit mask is composed of
the following values:
DEBUG_ADDRESSES (1)
Show buffer information during requests
DEBUG_RESID (4)
Go into debugger in complete_rqe().
DEBUG_LASTREQS (8)
Keep a circular buffer of last requests.
DEBUG_REVIVECONFLICT (16)
Print info about revive conflicts.
DEBUG_EOFINFO (32)
Print information about internal state when returning an
EOF on a striped plex.
DEBUG_MEMFREE (64)
Maintain a circular list of the last memory areas freed
by the memory allocator.
DEBUG_REMOTEGDB (256)
Go into remote gdb when the debug command is issued.
DEBUG_WARNINGS (512)
Print some warnings about minor problems in the implementation.
detach [-f] plex
detach [-f] subdisk
vinum detach removes the specified plex or subdisk from the volume
or plex to which it is attached. If removing the object
would impair the data integrity of the volume, the operation will
fail unless the -f option is specified. If the object is named
after the object above it (for example, subdisk vol1.p7.s0
attached to plex vol1.p7), the name will be changed by prepending
the text ``ex-'' (for example, ex-vol1.p7.s0). If necessary, the
name will be truncated in the process.
detach does not reduce the number of subdisks in a striped or
RAID-5 plex. Instead, the subdisk is marked absent, and can
later be replaced with the attach command.
dumpconfig [drive ...]
vinum dumpconfig shows the configuration information stored on
the specified drives. If no drive names are specified,
dumpconfig searches all drives on the system for Vinum partitions
and dumps the information. If configuration updates are disabled,
it is possible that this information is not the same as
the information returned by the list command. This command is
used primarily for maintenance and debugging.
info vinum info displays information about vinum memory usage. This
is intended primarily for debugging. With the -v option, it will
give detailed information about the memory areas in use.
With the -V option, info displays information about the last up
to 64 I/O requests handled by the vinum driver. This information
is only collected if debug flag 8 is set. The format looks like:
vinum -> info -V
Flags: 0x200 1 opens
Total of 38 blocks malloced, total memory: 16460
Maximum allocs: 56, malloc table at 0xf0f72dbc
Time Event Buf Dev Offset Bytes SD SDoff Doffset Goffset
14:40:00.637758 1VS Write 0xf2361f40 91.3 0x10 16384
14:40:00.639280 2LR Write 0xf2361f40 91.3 0x10 16384
14:40:00.639294 3RQ Read 0xf2361f40 4.39 0x104109 8192 19 0 0 0
14:40:00.639455 3RQ Read 0xf2361f40 4.23 0xd2109 8192 17 0 0 0
14:40:00.639529 3RQ Read 0xf2361f40 4.15 0x6e109 8192 16 0 0 0
14:40:00.652978 4DN Read 0xf2361f40 4.39 0x104109 8192 19 0 0 0
14:40:00.667040 4DN Read 0xf2361f40 4.15 0x6e109 8192 16 0 0 0
14:40:00.668556 4DN Read 0xf2361f40 4.23 0xd2109 8192 17 0 0 0
14:40:00.669777 6RP Write 0xf2361f40 4.39 0x104109 8192 19 0 0 0
14:40:00.685547 4DN Write 0xf2361f40 4.39 0x104109 8192 19 0 0 0
11:11:14.975184 Lock 0xc2374210 2 0x1f8001
11:11:15.018400 7VS Write 0xc2374210 0x7c0 32768 10
11:11:15.018456 8LR Write 0xc2374210 13.39 0xcc0c9 32768
11:11:15.046229 Unlock 0xc2374210 2 0x1f8001
The Buf field always contains the address of the user buffer
header. This can be used to identify the requests associated
with a user request, though this is not 100% reliable: theoretically
two requests in sequence could use the same buffer header,
though this is not common. The beginning of a request can be
identified by the event 1VS or 7VS. The first example above
shows the requests involved in a user request. The second is a
subdisk I/O request with locking.
The Event field contains information related to the sequence of
events in the request chain. The digit 1 to 6 indicates the
approximate sequence of events, and the two-letter abbreviation
is a mnemonic for the location:
1VS (vinumstrategy) shows information about the user
request on entry to vinumstrategy(). The device number
is the vinum device, and offset and length are the user
parameters. This is always the beginning of a request
sequence.
2LR (launch_requests) shows the user request just prior to
launching the low-level vinum requests in the function
launch_requests(). The parameters should be the same
as in the 1VS information.
In the following requests, Dev is the device number of the associated
disk partition, Offset is the offset from the beginning of
the partition, SD is the subdisk index in vinum_conf, SDoff is
the offset from the beginning of the subdisk, Doffset is the offset
of the associated data request, and Goffset is the offset of
the associated group request, where applicable.
3RQ (request) shows one of possibly several low-level vinum
requests which are launched to satisfy the high-level
request. This information is also logged in
launch_requests().
4DN (done) is called from complete_rqe(), showing the completion
of a request. This completion should match a
request launched either at stage 4DN from
launch_requests(), or from complete_raid5_write() at
stage 5RD or 6RP.
5RD (RAID-5 data) is called from complete_raid5_write() and
represents the data written to a RAID-5 data stripe
after calculating parity.
6RP (RAID-5 parity) is called from complete_raid5_write()
and represents the data written to a RAID-5 parity
stripe after calculating parity.
7VS shows a subdisk I/O request. These requests are usually
internal to vinum for operations like initialization
or rebuilding plexes.
8LR shows the low-level operation generated for a subdisk
I/O request.
Lockwait specifies that the process is waiting for a range lock.
The parameters are the buffer header associated with
the request, the plex number and the block number. For
internal reasons the block number is one higher than
the address of the beginning of the stripe.
Lock specifies that a range lock has been obtained. The
parameters are the same as for the range lock.
Unlock specifies that a range lock has been released. The
parameters are the same as for the range lock.
init [-S size] [-w] plex | subdisk
vinum init initializes a subdisk by writing zeroes to it. You
can initialize all subdisks in a plex by specifying the plex
name. This is the only way to ensure consistent data in a plex.
You must perform this initialization before using a RAID-5 plex.
It is also recommended for other new plexes. vinum initializes
all subdisks of a plex in parallel. Since this operation can
take a long time, it is normally performed in the background. If
you want to wait for completion of the command, use the -w (wait)
option.
Specify the -S option if you want to write blocks of a different
size from the default value of 16 kB. vinum prints a console
message when the initialization is complete.
label volume
The label command writes a ufs style volume label on a volume.
It is a simple alternative to an appropriate call to disklabel.
This is needed because some ufs commands still read the disk to
find the label instead of using the correct ioctl(2) call to
access it. vinum maintains a volume label separately from the
volume data, so this command is not needed for newfs(8). This
command is deprecated.
list [-r] [-V] [volume | plex | subdisk]
l [-r] [-V] [volume | plex | subdisk]
ld [-r] [-s] [-v] [-V] [volume]
ls [-r] [-s] [-v] [-V] [subdisk]
lp [-r] [-s] [-v] [-V] [plex]
lv [-r] [-s] [-v] [-V] [volume]
list is used to show information about the specified object. If
the argument is omitted, information is shown about all objects
known to vinum. The l command is a synonym for list.
The -r option relates to volumes and plexes: if specified, it
recursively lists information for the subdisks and (for a volume)
plexes subordinate to the objects. The commands lv, lp, ls and
ld list only volumes, plexes, subdisks and drives respectively.
This is particularly useful when used without parameters.
The -s option causes vinum to output device statistics, the -v
(verbose) option causes some additional information to be output,
and the -V causes considerable additional information to be output.
makedev
The makedev command removes the directory /dev/vinum and recreates
it with device nodes which reflect the current configuration.
This command is not intended for general use, and is provided
for emergency use only.
mirror [-f] [-n name] [-s] [-v] drives
The mirror command provides a simplified alternative to the
create command for creating mirrored volumes. Without any
options, it creates a RAID-1 (mirrored) volume with two concatenated
plexes. The largest contiguous space available on each
drive is used to create the subdisks for the plexes. The first
plex is built from the odd-numbered drives in the list, and the
second plex is built from the even-numbered drives. If the
drives are of different sizes, the plexes will be of different
sizes.
If the -s option is provided, mirror builds striped plexes with a
stripe size of 279 kB. The size of the subdisks in each plex is
the size of the smallest contiguous storage available on any of
the drives which form the plex. Again, the plexes may differ in
size.
Normally, the mirror command creates an arbitrary name for the
volume and its components. The name is composed of the text
``vinum'' and a small integer, for example ``vinum3''. You can
override this with the -n name option, which assigns the name
specified to the volume. The plexes and subdisks are named after
the volume in the default manner.
There is no choice of name for the drives. If the drives have
already been initialized as vinum drives, the name remains. Otherwise
the drives are given names starting with the text
``vinumdrive'' and a small integer, for example ``vinumdrive7''.
As with the create command, the -f option can be used to specify
that a previous name should be overwritten. The -v is used to
specify verbose output.
See the section SIMPLIFIED CONFIGURATION below for some examples
of this command.
mv -f drive object ...
move -f drive object ...
Move all the subdisks from the specified objects onto the new
drive. The objects may be subdisks, drives or plexes. When
drives or plexes are specified, all subdisks associated with the
object are moved.
The -f option is required for this function, since it currently
does not preserve the data in the subdisk. This functionality
will be added at a later date. In this form, however, it is
suited to recovering a failed disk drive.
printconfig [file]
Write a copy of the current configuration to file in a format
that can be used to recreate the vinum configuration. Unlike the
configuration saved on disk, it includes definitions of the
drives. If you omit file, vinum writes the list to stdout.
quit Exit the vinum utility when running in interactive mode. Normally
this would be done by entering the EOF character.
read disk ...
The read command scans the specified disks for vinum partitions
containing previously created configuration information. It
reads the configuration in order from the most recently updated
to least recently updated configuration. The vinum utility maintains
an up-to-date copy of all configuration information on each
disk partition. You must specify all of the slices in a configuration
as the parameter to this command.
The read command is intended to selectively load a vinum configuration
on a system which has other vinum partitions. If you want
to start all partitions on the system, it is easier to use the
start command.
If vinum encounters any errors during this command, it will turn
off automatic configuration update to avoid corrupting the copies
on disk. This will also happen if the configuration on disk
indicates a configuration error (for example, subdisks which do
not have a valid space specification). You can turn the updates
on again with the setdaemon and saveconfig commands. Reset bit 2
(numerical value 4) of the daemon options mask to re-enable configuration
saves.
rebuildparity plex [-f] [-v] [-V]
Rebuild the parity blocks on the specified RAID-4 or RAID-5 plex.
This operation maintains a pointer in the plex, so it can be
stopped and later restarted from the same position if desired.
In addition, this pointer is used by the checkparity command, so
rebuilding the parity blocks need only start at the location
where the first parity problem has been detected.
If the -f flag is specified, rebuildparity starts rebuilding at
the beginning of the plex. If the -v flag is specified,
rebuildparity first checks the existing parity blocks prints
information about those found to be incorrect before rebuilding.
If the -V flag is specified, rebuildparity prints a running
progress report.
rename [-r] [drive | subdisk | plex | volume] newname
Change the name of the specified object. If the -r option is
specified, subordinate objects will be named by the default
rules: plex names will be formed by appending .pnumber to the
volume name, and subdisk names will be formed by appending
.snumber to the plex name.
resetconfig
The resetconfig command completely obliterates the vinum configuration
on a system. Use this command only when you want to completely
delete the configuration. vinum will ask for confirmation;
you must type in the words NO FUTURE exactly as shown:
# vinum resetconfig
WARNING! This command will completely wipe out your vinum
configuration. All data will be lost. If you really want
to do this, enter the text
NO FUTURE
Enter text -> NO FUTURE
Vinum configuration obliterated
As the message suggests, this is a last-ditch command. Don't use
it unless you have an existing configuration which you never want
to see again.
resetstats [-r] [volume | plex | subdisk]
vinum maintains a number of statistical counters for each object.
See the header file <sys/dev/vinumvar.h> for more information.
Use the resetstats command to reset these counters. In conjunction
with the -r option, vinum also resets the counters of subordinate
objects.
rm [-f] [-r] volume | plex | subdisk
rm removes an object from the vinum configuration. Once an
object has been removed, there is no way to recover it. Normally
vinum performs a large amount of consistency checking before
removing an object. The -f option tells vinum to omit this
checking and remove the object anyway. Use this option with
great care: it can result in total loss of data on a volume.
Normally, vinum refuses to remove a volume or plex if it has subordinate
plexes or subdisks respectively. You can tell vinum to
remove the object anyway by using the -f option, or you can cause
vinum to remove the subordinate objects as well by using the -r
(recursive) option. If you remove a volume with the -r option,
it will remove both the plexes and the subdisks which belong to
the plexes.
saveconfig
Save the current configuration to disk. Normally this is not
necessary, since vinum automatically saves any change in configuration.
If an error occurs on startup, updates will be disabled.
When you reenable them with the setdaemon command, vinum does not
automatically save the configuration to disk. Use this command
to save the configuration.
setdaemon [value]
setdaemon sets a variable bitmask for the vinum daemon. This
command is temporary and will be replaced. Currently, the bit
mask may contain the bits 1 (log every action to syslog) and 4
(don't update configuration). Option bit 4 can be useful for
error recovery.
setstate state [volume | plex | subdisk | drive]
setstate sets the state of the specified objects to the specified
state. This bypasses the usual consistency mechanism of vinum
and should be used only for recovery purposes. It is possible to
crash the system by incorrect use of this command.
start [-i interval] [-S size] [-w] [plex | subdisk]
start starts (brings into to the up state) one or more vinum
objects.
If no object names are specified, vinum scans the disks known to
the system for vinum drives and then reads in the configuration
as described under the read commands. The vinum drive contains a
header with all information about the data stored on the drive,
including the names of the other drives which are required in
order to represent plexes and volumes.
If vinum encounters any errors during this command, it will turn
off automatic configuration update to avoid corrupting the copies
on disk. This will also happen if the configuration on disk
indicates a configuration error (for example, subdisks which do
not have a valid space specification). You can turn the updates
on again with the setdaemon and saveconfig command. Reset bit 4
of the daemon options mask to re-enable configuration saves.
If object names are specified, vinum starts them. Normally this
operation is only of use with subdisks. The action depends on
the current state of the object:
+o If the object is already in the up state, vinum does nothing.
+o If the object is a subdisk in the down or reborn states,
vinum changes it to the up state.
+o If the object is a subdisk in the empty state, the change
depends on the subdisk. If it is part of a plex which is
part of a volume which contains other plexes, vinum places
the subdisk in the reviving state and attempts to copy the
data from the volume. When the operation completes, the subdisk
is set into the up state. If it is part of a plex which
is part of a volume which contains no other plexes, or if it
is not part of a plex, vinum brings it into the up state
immediately.
+o If the object is a subdisk in the reviving state, vinum continues
the revive operation offline. When the operation completes,
the subdisk is set into the up state.
When a subdisk comes into the up state, vinum automatically
checks the state of any plex and volume to which it may belong
and changes their state where appropriate.
If the object is a plex, start checks the state of the subordinate
subdisks (and plexes in the case of a volume) and starts any
subdisks which can be started.
To start a plex in a multi-plex volume, the data must be copied
from another plex in the volume. Since this frequently takes a
long time, it is normally done in the background. If you want to
wait for this operation to complete (for example, if you are performing
this operation in a script), use the -w option.
Copying data doesn't just take a long time, it can also place a
significant load on the system. You can specify the transfer
size in bytes or sectors with the -S option, and an interval (in
milliseconds) to wait between copying each block with the -i
option. Both of these options lessen the load on the system.
stop [-f] [volume | plex | subdisk]
If no parameters are specified, stop removes the vinum kld and
stops vinum(4). This can only be done if no objects are active.
In particular, the -f option does not override this requirement.
Normally, the stop command writes the current configuration back
to the drives before terminating. This will not be possible if
configuration updates are disabled, so vinum will not stop if
configuration updates are disabled. You can override this by
specifying the -f option.
The stop command can only work if vinum has been loaded as a kld,
since it is not possible to unload a statically configured
driver. vinum stop will fail if vinum is statically configured.
If object names are specified, stop disables access to the
objects. If the objects have subordinate objects, the subordinate
objects must either already be inactive (stopped or in
error), or the -r and -f options must be specified. This command
does not remove the objects from the configuration. They can be
accessed again after a start command.
By default, vinum does not stop active objects. For example, you
cannot stop a plex which is attached to an active volume, and you
cannot stop a volume which is open. The -f option tells vinum to
omit this checking and remove the object anyway. Use this option
with great care and understanding: used incorrectly, it can
result in serious data corruption.
stripe [-f] [-n name] [-v] drives
The stripe command provides a simplified alternative to the
create command for creating volumes with a single striped plex.
The size of the subdisks is the size of the largest contiguous
space available on all the specified drives. The stripe size is
fixed at 279 kB.
Normally, the stripe command creates an arbitrary name for the
volume and its components. The name is composed of the text
``vinum'' and a small integer, for example ``vinum3''. You can
override this with the -n name option, which assigns the name
specified to the volume. The plexes and subdisks are named after
the volume in the default manner.
There is no choice of name for the drives. If the drives have
already been initialized as vinum drives, the name remains. Otherwise
the drives are given names starting with the text
``vinumdrive'' and a small integer, for example ``vinumdrive7''.
As with the create command, the -f option can be used to specify
that a previous name should be overwritten. The -v is used to
specify verbose output.
See the section SIMPLIFIED CONFIGURATION below for some examples
of this command.
SIMPLIFIED CONFIGURATION [Toc] [Back] This section describes a simplified interface to vinum configuration
using the concat, mirror and stripe commands. These commands create convenient
configurations for some more normal situations, but they are not
as flexible as the create command.
See above for the description of the commands. Here are some examples,
all performed with the same collection of disks. Note that the first
drive, /dev/da1h, is smaller than the others. This has an effect on the
sizes chosen for each kind of subdisk.
The following examples all use the -v option to show the commands passed
to the system, and also to list the structure of the volume. Without the
-v option, these commands produce no output.
Volume with a single concatenated plex [Toc] [Back]
Use a volume with a single concatenated plex for the largest possible
storage without resilience to drive failures:
vinum -> concat -v /dev/da1h /dev/da2h /dev/da3h /dev/da4h
volume vinum0
plex name vinum0.p0 org concat
drive vinumdrive0 device /dev/da1h
sd name vinum0.p0.s0 drive vinumdrive0 size 0
drive vinumdrive1 device /dev/da2h
sd name vinum0.p0.s1 drive vinumdrive1 size 0
drive vinumdrive2 device /dev/da3h
sd name vinum0.p0.s2 drive vinumdrive2 size 0
drive vinumdrive3 device /dev/da4h
sd name vinum0.p0.s3 drive vinumdrive3 size 0
V vinum0 State: up Plexes: 1 Size: 2134 MB
P vinum0.p0 C State: up Subdisks: 4 Size: 2134 MB
S vinum0.p0.s0 State: up D: vinumdrive0 Size: 414 MB
S vinum0.p0.s1 State: up D: vinumdrive1 Size: 573 MB
S vinum0.p0.s2 State: up D: vinumdrive2 Size: 573 MB
S vinum0.p0.s3 State: up D: vinumdrive3 Size: 573 MB
In this case, the complete space on all four disks was used, giving a
volume 2134 MB in size.
Volume with a single striped plex [Toc] [Back]
A volume with a single striped plex may give better performance than a
concatenated plex, but restrictions on striped plexes can mean that the
volume is smaller. It will also not be resilient to a drive failure:
vinum -> stripe -v /dev/da1h /dev/da2h /dev/da3h /dev/da4h
drive vinumdrive0 device /dev/da1h
drive vinumdrive1 device /dev/da2h
drive vinumdrive2 device /dev/da3h
drive vinumdrive3 device /dev/da4h
volume vinum0
plex name vinum0.p0 org striped 279k
sd name vinum0.p0.s0 drive vinumdrive0 size 849825b
sd name vinum0.p0.s1 drive vinumdrive1 size 849825b
sd name vinum0.p0.s2 drive vinumdrive2 size 849825b
sd name vinum0.p0.s3 drive vinumdrive3 size 849825b
V vinum0 State: up Plexes: 1 Size: 1659 MB
P vinum0.p0 S State: up Subdisks: 4 Size: 1659 MB
S vinum0.p0.s0 State: up D: vinumdrive0 Size: 414 MB
S vinum0.p0.s1 State: up D: vinumdrive1 Size: 414 MB
S vinum0.p0.s2 State: up D: vinumdrive2 Size: 414 MB
S vinum0.p0.s3 State: up D: vinumdrive3 Size: 414 MB
In this case, the size of the subdisks has been limited to the smallest
available disk, so the resulting volume is only 1659 MB in size.
Mirrored volume with two concatenated plexes [Toc] [Back]
For more reliability, use a mirrored, concatenated volume:
vinum -> mirror -v -n mirror /dev/da1h /dev/da2h /dev/da3h /dev/da4h
drive vinumdrive0 device /dev/da1h
drive vinumdrive1 device /dev/da2h
drive vinumdrive2 device /dev/da3h
drive vinumdrive3 device /dev/da4h
volume mirror setupstate
plex name mirror.p0 org concat
sd name mirror.p0.s0 drive vinumdrive0 size 0b
sd name mirror.p0.s1 drive vinumdrive2 size 0b
plex name mirror.p1 org concat
sd name mirror.p1.s0 drive vinumdrive1 size 0b
sd name mirror.p1.s1 drive vinumdrive3 size 0b
V mirror State: up Plexes: 2 Size: 1146 MB
P mirror.p0 C State: up Subdisks: 2 Size: 988 MB
P mirror.p1 C State: up Subdisks: 2 Size: 1146 MB
S vinum0.p0.s0 State: up D: vinumdrive0 Size: 414 MB
S vinum0.p0.s2 State: up D: vinumdrive2 Size: 414 MB
S vinum0.p0.s1 State: up D: vinumdrive1 Size: 414 MB
S vinum0.p0.s3 State: up D: vinumdrive3 Size: 414 MB
This example specifies the name of the volume, mirror. Since one drive
is smaller than the others, the two plexes are of different size, and the
last 158 MB of the volume is non-resilient. To ensure complete reliability
in such a situation, use the create command to create a volume with
988 MB.
Mirrored volume with two striped plexes [Toc] [Back]
Alternatively, use the -s option to create a mirrored volume with two
striped plexes:
vinum -> mirror -v -n raid10 -s /dev/da1h /dev/da2h /dev/da3h /dev/da4h
drive vinumdrive0 device /dev/da1h
drive vinumdrive1 device /dev/da2h
drive vinumdrive2 device /dev/da3h
drive vinumdrive3 device /dev/da4h
volume raid10 setupstate
plex name raid10.p0 org striped 279k
sd name raid10.p0.s0 drive vinumdrive0 size 849825b
sd name raid10.p0.s1 drive vinumdrive2 size 849825b
plex name raid10.p1 org striped 279k
sd name raid10.p1.s0 drive vinumdrive1 size 1173665b
sd name raid10.p1.s1 drive vinumdrive3 size 1173665b
V raid10 State: up Plexes: 2 Size: 1146 MB
P raid10.p0 S State: up Subdisks: 2 Size: 829 MB
P raid10.p1 S State: up Subdisks: 2 Size: 1146 MB
S raid10.p0.s0 State: up PO: 0 B Size: 414 MB
S raid10.p0.s1 State: up PO: 279 kB Size: 414 MB
S raid10.p1.s0 State: up PO: 0 B Size: 573 MB
S raid10.p1.s1 State: up PO: 279 kB Size: 573 MB
In this case, the usable part of the volume is even smaller, since the
first plex has shrunken to match the smallest drive.
The vinum utility requires that all parameters to the create commands
must be in a configuration file. Entries in the configuration file
define volumes, plexes and subdisks, and may be in free format, except
that each entry must be on a single line.
Scale factors [Toc] [Back]
Some configuration file parameters specify a size (lengths, stripe
sizes). These values can be specified as bytes, or one of the following
scale factors may be appended:
s specifies that the value is a number of sectors of 512 bytes.
k specifies that the value is a number of kilobytes (1024 bytes).
m specifies that the value is a number of megabytes (1048576
bytes).
g specifies that the value is a number of gigabytes (1073741824
bytes).
b is used for compatibility with VERITAS. It stands for blocks of
512 bytes. This abbreviation is confusing, since the word
``block'' is used in different meanings, and its use is deprecated.
Use the keyword 's' instead.
For example, the value 16777216 bytes can also be written as 16m, 16384k
or 32768s.
The configuration file can contain the following entries:
drive name devicename [options]
Define a drive. The options are:
device devicename Specify the device on which the drive resides.
devicename must be the name of a disk partition,
for example /dev/da1e or /dev/ad3s2h, and
it must be of type vinum. Do not use the ``c''
partition, which is reserved for the complete
disk.
hotspare Define the drive to be a ``hot spare'' drive,
which is maintained to automatically replace a
failed drive. The vinum utility does not allow
this drive to be used for any other purpose.
In particular, it is not possible to create
subdisks on it. This functionality has not
been completely implemented.
volume name [options]
Define a volume with name name. Options are:
plex plexname Add the specified plex to the volume. If
plexname is specified as *, vinum will look for
the definition of the plex as the next possible
entry in the configuration file after the definition
of the volume.
readpol policy Define a read policy for the volume. policy
may be either round or prefer plexname. The
vinum utility satisfies a read request from
only one of the plexes. A round read policy
specifies that each read should be performed
from a different plex in round-robin fashion.
A prefer read policy reads from the specified
plex every time.
setupstate When creating a multi-plex volume, assume that
the contents of all the plexes are consistent.
This is normally not the case, so by default
vinum sets all plexes except the first one to
the faulty state. Use the start command to
first bring them to a consistent state. In the
case of striped and concatenated plexes, however,
it does not normally cause problems to
leave them inconsistent: when using a volume
for a file system or a swap partition, the previous
contents of the disks are not of interest,
so they may be ignored. If you want to
take this risk, use the setupstate keyword. It
will only apply to the plexes defined immediately
after the volume in the configuration
file. If you add plexes to a volume at a later
time, you must integrate them manually with the
start command.
Note that you must use the init command with
RAID-5 plexes: otherwise extreme data corruption
will result if one subdisk fails.
plex [options]
Define a plex. Unlike a volume, you do not need to specify a name
for a plex. The options may be:
name plexname Specify the name of the plex. Note that you
must use the keyword name when naming a plex or
subdisk.
org organization [stripesize]
Specify the organization of the plex.
organization can be one of concat, striped or
raid5. For striped and raid5 plexes, the
parameter stripesize must be specified, while
for concat it must be omitted. For type
striped, it specifies the width of each stripe.
For type raid5, it specifies the size of a
group. A group is a portion of a plex which
stores the parity bits all in the same subdisk.
It must be a factor of the plex size (in other
words, the result of dividing the plex size by
the stripe size must be an integer), and it
must be a multiple of a disk sector (512
bytes).
For optimum performance, stripes should be at
least 128 kB in size: anything smaller will
result in a significant increase in I/O activity
due to mapping of individual requests over
multiple disks. The performance improvement
due to the increased number of concurrent
transfers caused by this mapping will not make
up for the performance drop due to the increase
in latency. A good guideline for stripe size
is between 256 kB and 512 kB. Avoid powers of
2, however: they tend to cause all superblocks
to be placed on the first subdisk. The simplified
commands use a stripe size of 279 kB,
which shows a reasonable distribution of
superblocks.
A striped plex must have at least two subdisks
(otherwise it is a concatenated plex), and each
must be the same size. A RAID-5 plex must have
at least three subdisks, and each must be the
same size. In practice, a RAID-5 plex should
have at least 5 subdisks.
volume volname Add the plex to the specified volume. If no
volume keyword is specified, the plex will be
added to the last volume mentioned in the configuration
file.
sd sdname offset Add the specified subdisk to the plex at offset
offset.
subdisk [options]
Define a subdisk. Options may be:
name name Specify the name of a subdisk. It is not necessary
to specify a name for a subdisk--see
OBJECT NAMING above. Note that you must specify
the keyword name if you wish to name a subdisk.
plexoffset offset Specify the starting offset of the subdisk in
the plex. If not specified, vinum allocates
the space immediately after the previous subdisk,
if any, or otherwise at the beginning of
the plex.
driveoffset offset Specify the starting offset of the subdisk in
the drive. If not specified, vinum allocates
the first contiguous length bytes of free space
on the drive.
length length Specify the length of the subdisk. This keyword
must be specified. There is no default,
but the value 0 may be specified to mean ``use
the largest available contiguous free area on
the drive''. If the drive is empty, this means
that the entire drive will be used for the subdisk.
length may be shortened to len.
plex plex Specify the plex to which the subdisk belongs.
By default, the subdisk belongs to the last
plex specified.
drive drive Specify the drive on which the subdisk resides.
By default, the subdisk resides on the last
drive specified.
retryerrors Specify that the subdisk should not be taken
down if an unrecoverable error occurs. Normally
vinum responds to an unrecoverable error
by making the entire subdisk inaccessible.
EXAMPLE CONFIGURATION FILE [Toc] [Back] # Sample vinum configuration file
#
# Our drives
drive drive1 device /dev/da1h
drive drive2 device /dev/da2h
drive drive3 device /dev/da3h
drive drive4 device /dev/da4h
drive drive5 device /dev/da5h
drive drive6 device /dev/da6h
# A volume with one striped plex
volume tinyvol
plex org striped 279k
sd length 64m drive drive2
sd length 64m drive drive4
volume stripe
plex org striped 279k
sd length 512m drive drive2
sd length 512m drive drive4
# Two plexes
volume concat
plex org concat
sd length 100m drive drive2
sd length 50m drive drive4
plex org concat
sd length 150m drive drive4
# A volume with one striped plex and one concatenated plex
volume strcon
plex org striped 279k
sd length 100m drive drive2
sd length 100m drive drive4
plex org concat
sd length 150m drive drive2
sd length 50m drive drive4
# a volume with a RAID-5 and a striped plex
# note that the RAID-5 volume is longer by
# the length of one subdisk
volume vol5
plex org striped 491k
sd length 1000m drive drive2
sd length 1000m drive drive4
plex org raid5 273k
sd length 500m drive drive1
sd length 500m drive drive2
sd length 500m drive drive3
sd length 500m drive drive4
sd length 500m drive drive5
DRIVE LAYOUT CONSIDERATIONS [Toc] [Back] vinum drives are currently BSD disk partitions. They must be of type
vinum in order to avoid overwriting data used for other purposes. Use
disklabel -e to edit a partition type definition. The following display
shows a typical partition layout as shown by disklabel(8):
8 partitions:
# size offset fstype [fsize bsize bps/cpg]
a: 81920 344064 4.2BSD 0 0 0 # (Cyl. 240*- 297*)
b: 262144 81920 swap # (Cyl. 57*- 240*)
c: 4226725 0 unused 0 0 # (Cyl. 0 - 2955*)
e: 81920 0 4.2BSD 0 0 0 # (Cyl. 0 - 57*)
f: 1900000 425984 4.2BSD 0 0 0 # (Cyl. 297*- 1626*)
g: 1900741 2325984 vinum 0 0 0 # (Cyl. 1626*- 2955*)
In this example, partition ``g'' may be used as a vinum partition. Partitions
``a'', ``e'' and ``f'' may be used as UFS file systems or ccd
partitions. Partition ``b'' is a swap partition, and partition ``c''
represents the whole disk and should not be used for any other purpose.
The vinum utility uses the first 265 sectors on each partition for configuration
information, so the maximum size of a subdisk is 265 sectors
smaller than the drive.
The vinum utility maintains a log file, by default
/var/log/vinum_history, in which it keeps track of the commands issued to
vinum. You can override the name of this file by setting the environment
variable VINUM_HISTORY to the name of the file.
Each message in the log file is preceded by a date. The default format
is "%e %b %Y %H:%M:%S". See strftime(3) for further details of the format
string. It can be overridden by the environment variable
VINUM_DATEFORMAT.
This section gives practical advice about how to implement a vinum system.
Where to put the data [Toc] [Back]
The first choice you need to make is where to put the data. You need
dedicated disk partitions for vinum. They should be partitions, not
devices, and they should not be partition ``c''. For example, good names
are /dev/da0e or /dev/ad3s4a. Bad names are /dev/da0 and /dev/da0s1,
both of which represent a device, not a partition, and /dev/ad1c, which
represents a complete disk and should be of type unused. See the example
under DRIVE LAYOUT CONSIDERATIONS above.
Designing volumes [Toc] [Back]
The way you set up vinum volumes depends on your intentions. There are a
number of possibilities:
1. You may want to join up a number of small disks to make a reasonable
sized file system. For example, if you had five small drives and
wanted to use all the space for a single volume, you might write a
configuration file like:
drive d1 device /dev/da2e
drive d2 device /dev/da3e
drive d3 device /dev/da4e
drive d4 device /dev/da5e
drive d5 device /dev/da6e
volume bigger
plex org concat
sd length 0 drive d1
sd length 0 drive d2
sd length 0 drive d3
sd length 0 drive d4
sd length 0 drive d5
In this case, you specify the length of the subdisks as 0, which
means ``use the largest area of free space that you can find on the
drive''. If the subdisk is the only subdisk on the drive, it will
use all available space.
2. You want to set up vinum to obtain additional resilience against
disk failures. You have the choice of RAID-1, also called
``mirroring'', or RAID-5, also called ``parity''.
To set up mirroring, create multiple plexes in a volume. For example,
to create a mirrored volume of 2 GB, you might create the following
configuration file:
drive d1 device /dev/da2e
drive d2 device /dev/da3e
volume mirror
plex org concat
sd length 2g drive d1
plex org concat
sd length 2g drive d2
When creating mirrored drives, it is important to ensure that the
data from each plex is on a different physical disk so that vinum
can access the complete address space of the volume even if a drive
fails. Note that each plex requires as much data as the complete
volume: in this example, the volume has a size of 2 GB, but each
plex (and each subdisk) requires 2 GB, so the total disk storage
requirement is 4 GB.
To set up RAID-5, create a single plex of type raid5. For example,
to create an equivalent resilient volume of 2 GB, you might use the
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