vxtrace(1M) VxVM 3.5 vxtrace(1M)
1 Jun 2002
NAME [Toc] [Back]
vxtrace - trace operations on volumes
SYNOPSIS [Toc] [Back]
vxtrace [-aeEls ] [-b buffersize] [-c eventcount]
[-d outputfile] [-f inputfile] [-g diskgroup]
[-k buffersize] [-m millisec_delay]
[-o objtype [,objtype]...] [-t timeout]
[-w waitinterval] [name | device]...
DESCRIPTION [Toc] [Back]
The vxtrace utility prints kernel error or I/O trace event records on
the standard output or writes them to a file in binary format. Binary
trace records written to a file can be read back and formatted by
vxtrace as well.
If no arguments are specified, vxtrace reports either all error trace
data or all I/O trace data on all virtual disk devices. With error
trace data, it is possible to select all accumulated error trace data,
to wait for new error trace data, or both (the default). Selection
can be limited to a specific disk group, to specific types of VERITAS
Volume Manager (VxVM) kernel I/O objects, or to particular named
objects or devices.
Under heavy loads, the kernel may discard one or more records before
they can be reported to vxtrace. Even though the contents of the
records are lost, the kernel keeps track of the number of lost records
and reports this to vxtrace. as a record. vxtrace displays this
record indicating that records were lost. You can increase the size
of the kernel buffer using the -k buffersize option to reduce the
likelihood of the kernel discarding records.
OPTIONS [Toc] [Back]
-a Appends to the outputfile instead of truncating it. By
default, the output file is truncated.
-b buffersize
Sets the size of the buffer used by vxtrace when it obtains
trace records from the kernel, or from a file when the -f
option is specified. The buffer size is specified as a
standard VERITAS Volume Manager length (see vxintro(1M)).
The default buffer size is 8K.
-c eventcount
Accumulates at most eventcount events and then exits. The
timeout and eventcount options can be used together.
-d outputfile
Writes (dumps) binary trace data to the specified output
file.
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-e Selects new error trace data. The default is to select I/O
trace data.
-E Selects pre-existing error trace data. This can be combined
with -e to get both pre-existing trace data and new trace
data.
-f inputfile
Reads binary trace data from the specified input file,
instead of from the VERITAS Volume Manager kernel.
-g diskgroup
Selects objects from the specified disk group. The disk
group can be specified either by disk group ID or by disk
group name. With no name or device arguments, all
appropriate objects in the disk group are selected. With
the name argument, diskgroup specifies the disk group that
contains the named configuration record.
-k buffersize
Sets the kernel I/O trace buffer size. The VERITAS Volume
Manager kernel allocates a private kernel space to buffer
the I/O trace records for each vxtrace command. The default
buffer size is 8K bytes. Some trace records may be
discarded if the trace buffer is too small. This option can
be used to set a larger or a smaller kernel trace buffer
size. The buffer size is specified as a standard VERITAS
Volume Manager length (see vxintro(1M)). Depending on the
VERITAS Volume Manager kernel configuration, usually only a
maximum buffer size of 1 megabyte is granted.
-l Long format. Prints all available fields for all tracing
records, instead of a subset of the available fields. The
default is to use the short format.
-m millisec_delay
Pauses vxtrace for the specified period to allow more
records to accumulate.
name | device
If name or device are specified, VERITAS Volume Manager
kernel objects of the requested types are selected if they
are associated with the configuration records or virtual
disk devices indicated by those arguments.
-o objtype [,objtype]...
Selects object based on the objtype option arguments.
Multiple types of objects can be specified with one or
several -o options. The possible object selection types
are:
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all | ALL Selects all possible virtual disk devices, kernel
objects, and physical disks.
dev | logical
Selects virtual disk devices.
disk | physical
Selects VERITAS Volume Manager physical disks.
log Selects all log objects.
logplex Selects RAID-5 log plexes.
logsd Selects DRL (dirty region logging) or RAID-5 log
subdisks.
logvol Selects DRL or RAID-5 log volumes.
m | mv | mirror
Selects mirrored volume kernel objects.
p | pl | plex
Selects striped or concatenated plex kernel
objects.
rl | rlink
Selects RLINK kernel objects. If an RVG
(replicated volume group) is specified, all RLINKs
associated with that RVG are selected.
s | sd | subdisk
Selects subdisk kernel objects.
v | vol | volume
Selects mirrored or RAID-5 volume kernel objects.
-s Specifies using synchronous writes to the outputfile instead
of asynchronous writes. Asynchronous writes is the default.
-t timeout
Accumulates trace data for at most timeout seconds, then
exits.
-w waitinterval
If vxtrace waits for waitinterval seconds without receiving
any new events, prints waiting... to allow scripts to wake
up and process previously accumulated events. This is
useful for processing errors. The waiting... message does
not count as an event for the purposes of the -c option.
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ARGUMENTS [Toc] [Back]
Arguments specify configuration record names, or physical or virtual
disk device nodes (by device path). If no object types were selected
with the -o option, only trace records corresponding to the indicated
configuration records or devices are selected; otherwise, objects of
the requested types are selected if they are associated in any way
with the named configuration record or device.
If a name argument does not match a regular configuration record, but
does match a disk access record, the indicated physical disk is
selected. Physical disks can also be selected by the disk media
record name.
By default, name arguments are searched for in all disk groups or in
the disk group specified using the -g option. Without the -g option,
a record that is found in more than one disk group generates an error
unless the record is in the rootdg disk group (in which case, the
record in the rootdg disk group is selected). The disk group for any
individual name argument can be overridden using the form:
diskgroup/recordname
Note: When reading trace data from a file with the -f option,
association information is not available.
EXAMPLES [Toc] [Back]
To trace all physical disk I/Os, enter:
vxtrace -o disk
To trace virtual disk device I/Os to the device associated with volume
testvol, use either of the commands:
vxtrace -o dev testvol
vxtrace /dev/vx/dsk/testvol
To trace all log subdisks associated with volume testvol, enter:
vxtrace -o logsd testvol
To trace all log objects, enter:
vxtrace -o log
To accumulate ten seconds worth of trace data for disk04 and then
format that data, use:
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vxtrace(1M) VxVM 3.5 vxtrace(1M)
1 Jun 2002
vxtrace -t 10 -d /tmp/tracedata disk04
vxtrace -l -f /tmp/tracedata
To read error trace data into a script for processing, using ten
second pauses to generate mail messages, use the command:
vxtrace -leE -w 10 | while read ...
FILES [Toc] [Back]
/dev/vx/trace
SEE ALSO [Toc] [Back]
vxintro(1M), vxstat(1M), vxtrace(7)
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