Reoccuring ZFS performance problems

[Steven Hartland]

----- Original Message ----- 
From: "Adrian Gschwend" <ml-ktk at netlabs.org>
To: "Steven Hartland" <killing at multiplay.co.uk>
Cc: <freebsd-fs at freebsd.org>
Sent: Monday, March 10, 2014 5:40 PM
Subject: Re: Reoccuring ZFS performance problems


> On 10.03.14 18:31, Steven Hartland wrote:
> 
> 
> 
>> Looks like you may be out of IOP/s but just incase, are you using TRIM
>> at all?
>> sysctl -a |grep trim
> 
> vfs.zfs.vdev.trim_on_init: 1
> vfs.zfs.vdev.trim_max_pending: 64
> vfs.zfs.vdev.trim_max_bytes: 2147483648
> vfs.zfs.trim.enabled: 1
> vfs.zfs.trim.max_interval: 1
> vfs.zfs.trim.timeout: 30
> vfs.zfs.trim.txg_delay: 32
> kstat.zfs.misc.zio_trim.bytes: 0
> kstat.zfs.misc.zio_trim.success: 0
> kstat.zfs.misc.zio_trim.unsupported: 115
> kstat.zfs.misc.zio_trim.failed: 0
> 
> so looks like trim is enabled

Its enabled but not in use as the devices are reporting unsupported.
 
>> If you are what does "gstat -d" show?
> 
> It looks like finally my MySQL process finished and now the system is
> back to completely fine:
> 
> dT: 1.010s  w: 1.000s
> L(q)  ops/s    r/s   kBps   ms/r    w/s   kBps   ms/w    d/s   kBps
> ms/d   %busy Name
>   10    203      0      0    0.0    192   1674   38.8      0      0
> 0.0   95.2| vtbd0
>    0      0      0      0    0.0      0      0    0.0      0      0
> 0.0    0.0| vtbd0p1
>    0      0      0      0    0.0      0      0    0.0      0      0
> 0.0    0.0| vtbd0p2
>   10    203      0      0    0.0    192   1674   39.0      0      0
> 0.0   95.5| vtbd0p3
>    0      0      0      0    0.0      0      0    0.0      0      0
> 0.0    0.0| cd0
>    0      0      0      0    0.0      0      0    0.0      0      0
> 0.0    0.0| gptid/e402ecce-89ca-11e2-a867-3264262b9894
>    0      0      0      0    0.0      0      0    0.0      0      0
> 0.0    0.0| gptid/e4112d88-89ca-11e2-a867-3264262b9894
> 
> I restarted MySQL now, curious how long it will take.
> 
>> You also mention your using mysql, have you applied the standard tuning
>> for mysql on ZFS?
> 
> At first I didn't so anything special with MySQL, during the process I
> redid the MySQL ZFS with a new record size:
> 
> # zfs get recordsize tank/storage/data/db/data
> NAME                       PROPERTY    VALUE    SOURCE
> tank/storage/data/db/data  recordsize  16K      local

Disabled atime, configured innodb settings?

    Regards
    Steve

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