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disktest - Disk Test Environment
disktest [ -B ] [ -t minutes ] [ -v ] [ adapter ]
disktest -T [ -t minutes ] [ -v ] adapter
disktest [ -R ] [ -W ] [ -A ] [ -WV ] [ -V ] [ -B ] [ -t
minutes ] [ -n sects ] [ -v ] [ -s <shelf-list> ] [ -d
<disk-list> ] [ -a <adapter-list> ]
Use the disktest command to test all types of disks on an
appliance. This command provides a report of the
integrity of your storage environment. It is only available
in maintenance mode. By default, it takes about 5
minutes to complete.
The -R option executes a sequential read test with optionally
specified large block size (default is 1024kb per
I/O).
The -W option executes a sequential write test with
optionally specified large block size (default is 1024kb
per I/O).
The -A option executes a test that alternates between
writes and reads with optionally specified large block
size (default is 1024kb per I/O). No data verification is
peformed.
The -WV option executes a sequential write verify test
which uses 4kb per I/O operation. This is identical to the
way disktest would function with -V option on previous
releases.
The -V option executes a sequential SCSI verify test which
uses 10MB per operation. This test will run for one complete
pass to verify all sectors on the disk regardless of
-T option.
The -T option executes a test that alternates between
writes and reads with varying I/O sizes. It also steps
through permutations of shelves on the specified loop. If
-t minutes is specified, each iteration of the test will
run for the specified time. This test is a continuous test
and will run until stopped via ^C.
The -n option is used to optionally specify the number of
sectors to be read for each I/O of the -R,-A or -W option.
The number of sectors used by the the -WV command is fixed
at 8 (4kb) and cannot be altered. The number of sectors
used by the -V command is fixed at 20480 (10MB) to
increase throughput and cannot be altered.
The -d option allows for running disktest over a specific
set of disks in the system by specifying a disk list of
the form: <disk-name1> <disk-name2>
The -s option allows for running disktest over all disks
contained in a specific shelf by specifying a shelf list
of the form: <a>:<m> [<b>:<n> ...] where <m> and <n> are
integer shelf ids and <a> and <b> are the PCI slot numbers
of the Adapter(s) the shelves are connected to. (on board
adapter is slot 0a) Hint: use fcadmin device_map to get
slot locations.
The -a option allows for running disktest over a specific
set of adapters in the system by specifying an adapter
list of the form: <slot1> <slot2> ... <slotN>.
If the -v option is specified, the output is verbose.
If the -B option is specified, disks attached to a Fibre
Channel loop via their B ports will also be tested.
By default, the test runs for about 5 minutes. However, if
the [ -t minutes ] option is used, the test will run for
the specified duration. If [ -t 0 ] is specified, the test
will run CONTINUOUSLY until stopped with a ^C.
If the adapter or disk-list, adapter-list and shelf-list
arguments are missing, all adapters and disks in the system
are tested. Otherwise, only the specified adapter and
disks attached to it are tested.
When finished, disktest prints out a report of the following
values for each Fibre Channel adapter tested:
1. Number of times loss of synchronization was
detected in that adapter's Fibre Channel loop.
2. Number of CRC errors found in Fibre Channel
packets.
3. The total number of inbound and outbound frames
seen by the adapter.
4. A "confidence factor" on a scale from 0 to 1
that indicates the health of your disk system as
computed by the test. A value of 1 indicates that
no errors were found. Any value less than 1 indicates
there are problems in the Fibre Channel loop
that are likely to intefere with the normal operation
of your appliance. For more information see
the Easy Installation Instructions for your specific
filer or your storage shelf guide.
If the confidence factor is reported as less than 1,
please go through the troubleshooting checklist for Fibre
Channel loop problems in the document "Easy Installation
Instructions for NetApp Filers" and re-run the disktest
command after making any suggested modifications to your
Fibre Channel setup. If the problem persists, please call
your Customer Support telephone number.
The actual arithmetic that is used to compute the confidence
factor is as follows:
The number of errors is obtained by adding the number of
underrun, CRC, Synchronization and link failure errors
with all errors weighted the same.
The allowable number of errors by the Fibrechannel
protocol is calculated by adding fibre channel frames
(inbound + outbound) and then multiplying by 2048 bytes
per frame and dividing by the BER of 1e-12 converted to
bytes at 1e-11.
The confidence factor is calculated as follows:
if total errors = 0 then confidence factor = 1.0
if total errors < allowable errors then confidence factor
= 0.99
if total errors > allowable errors then confidence factor
is decremented by .01 for each error seen which the protocol
error rate does not allow.
When finished, disktest prints out a report of the following
values for each adapter tested:
1. Number of Write operations performed on an
adapter.
2. Number of Read operations performed on an
adapter.
3. IOPS (I/O's per second) performed on an adapter.
4. Data rate in MB/S of the adapter.
5. Data transfer size per I/O operation on the
adapter.
6. Number of soft (recovered) errors on the
adapter.
7. Number of hard (unrecoverable) errors on the
adapter.
8. A "confidence factor" on a scale from 0 to 1
that indicates the health of your disk system as
computed by the test. A value of 1 indicates that
no errors were found. Any value less than 1 indicates
there are problems in the loop or bus or disk
that are likely to intefere with the normal operation
of your appliance. For more information see
the Easy Installation Instructions for your specific
filer or your storage shelf guide.
If the confidence factor is reported as less than 1, and a
disk is reporting hard errors, you may want to proactively
fail that disk or call your Customer Support telephone
number.
The actual arithmetic that is used to compute the confidence
factor is as follows:
The number of errors is obtained by adding the number of
hard and soft errors from the disk with all errors
weighted the same.
The allowable number of errors is zero for SCSI devices.
The confidence factor is calculated as follows:
if total errors = 0 then confidence factor = 1.0
if total errors > 0 then confidence factor is decremented
by .01 for each error seen.
In a clustered configuration, only disks on a filer's FCAL
primary loop (the A loop) are tested, unless the -B
option is specified. If -B is specified, disks on the B
loop are tested as well.
The following command runs disktest for 5 minutes doing a
sequential alternating write and read test in verbose mode
on all adapters in the system, while testing only those
disks which are attached via their A ports:
disktest -v
The following command runs disktest for an hour doing a
sequential write test in verbose mode, using 1024kb I/O
blocks while testing disks attached to adapter 8 via both
A and B ports:
disktest -W -v -B -t 60 -a 8
The following command runs disktest for 5 minutes doing a
sequential read test on all disks in shelf 0 on adapter 7.
disktest -R -s 7:0
The following command runs disktest continuously (until
stopped) doing a sequential write test of 512kb I/O's to
all disks on shelf 1 on adapter 7, shelf 2 on adapter 7,
disks 7.0 and 7.1 and all disks on adapter 8.
disktest -W -n 1024 -t 0 -d 7.0 7.1 -s 7:1 7:2 -a 8
The following command runs disktest continuously (until
stopped) doing an alternating sequential write/read test
with varying I/O sizes across all shelf permutations in
the loop attached to adapter 7 for 4 minutes on each iteration.
disktest -T -t 4 7
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