Does "man blktrace" sound useful to you? With this command and others you can
produce "funny output" like this:
9-1 A W 271 68123744 16 153.802866844 1 1057 xfsbufd/dm-12
9-1 Q W 272 68123744 16 153.802871575 1 1057 xfsbufd/dm-12
9-1 A W 273 161876032 16 153.802877568 1 1057 xfsbufd/dm-12
9-1 Q W 274 161876032 16 153.802877938 1 1057 xfsbufd/dm-12
(the above example is tracing an MD-RAID1)
The RAID leg in a virtual machine produces output like this:
202-80 Q WS 496 63353637 88 11.636835786 0 799 md1_raid1
202-80 G WS 497 63353637 88 11.636837191 0 799 md1_raid1
202-80 Q WS 498 63353725 29 11.636838296 0 799 md1_raid1
202-80 G WS 499 63353725 29 11.636838924 0 799 md1_raid1
202-80 I WS 500 63353555 82 11.636854804 0 799 md1_raid1
202-80 I WS 501 63353637 88 11.636855654 0 799 md1_raid1
202-80 I WS 502 63353725 29 11.636855895 0 799 md1_raid1
A crude sketch of commands to produce the files like above is:
ACTIONS=$(echo 'issue,complete,read,write' |
sed -e 's/,/ -a /g; s/^/-a /')
trace()
{
blktrace -d "$1" $ACTIONS -w "$2" -o - |
blkparse -i - -f '%M-%m %2a %4d %10s %10S %4n %5T.%t %c %5p %C\n' -o $3 &
}
#...
: ${OBASE:=/tmp/blocktrace-}
OUTFILE=${OBASE}$(date -u '+%Y%m%d_%H%M')-${NAME}.out
echo "trace $DEV ($NAME) to $OUTFILE for $DURATION seconds"
trace /dev/${DEV#/dev/} $DURATION $OUTFILE
Regards,
Ulrich
>>> Stefan B <stefj...@gmail.com> schrieb am 09.12.2014 um 09:22 in Nachricht
<fcc4fab0-7f1d-4070-85fe-99803c76a...@googlegroups.com>:
> Thanks for the messages,
>
> I have change the open-iscsi settings with Citrix Perfomance settings, and
> i have set the blockdev to 16384, i see more perfomance.
>
> But the first dir or commando on the dir, give the same slow perfomace, it
> wil be taken more than 30 secondes.
>
> We not running any nis or radius server.
>
> On Wednesday, December 3, 2014 8:24:06 AM UTC+1, Uli wrote:
>>
>> >>> <stef...@gmail.com <javascript:>> schrieb am 02.12.2014 um 15:06 in
>> Nachricht
>> <5a7097b3-0dd7-4c28-abbf-ff66800b8...@googlegroups.com <javascript:>>:
>> > We have 2 Equallogic Systems, And a Dell Servers.
>> >
>> > We have every server give a block device home dir , so the user data are
>> on
>> > the home dir this is working great its format on xfs filesystem, and
>> > running iscsiadm version 2.0-870 with linux kernel 3.10.57
>> >
>> > But when we logging on the server, the first time we do a dir command on
>> > the home dir, its take a long time when we get feedback on the dir , the
>> > next time is fast when we do a dir.
>>
>> Are you sure it's related to iSCSI? Especially for the /home dire several
>> different UIDs/GIDs are involved. We had a slow "ls -l /home" performance
>> when the NIS server had a problem. Maybe you use LDAP or something else?
>> Maybe try "hdparm -t <block_device>" to get a rough number how fast your
>> block device can be read. I know there are better tests, but this one is
>> quick and easy to perform...
>>
>> > Now we have users on this systems and this problem give not good
>> > performance on sql and websites an e-mail we are running on the server.
>>
>> You are running a database ("sql") via iSCSI?
>>
>> >
>> > Are the some information how i can fix ore maybe get this problem better
>> > under control ?
>> >
>> > I hope so that somebody can help me, i am searching for more than 3
>> weeks
>> > now.
>> >
>> > --
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>>
>>
>>
>>
>
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