Re: ZFS secondarycache on SSD problem on r255173

I'm not clear what you rolled back there as r255173 has ntothing to do
with this. Could you clarify

Any errors recorded in /var/log/messages?

Could you add code to record the none zero value of zio->io_error in
l2arc_read_done as this may give some indication of the underlying
issue.

Additionally could always put a panic in that code path too and then
create a dump so the details can be fully exhamined.

In terms of the slowness thats going to be a side effect of the cache
failures.

Oh could you also confirm that the issue doesn't exist if you
1. Exclude r255753
2. Set vfs.zfs.max_auto_ashift=9

    Regards
    Steve
----- Original Message ----- 
From: "Vitalij Satanivskij" <satan_at_ukr.net>
To: "Steven Hartland" <killing_at_multiplay.co.uk>
Cc: "Vitalij Satanivskij" <satan_at_ukr.net>; "Dmitriy Makarov" <supportme_at_ukr.net>; "Justin T. Gibbs" <gibbs_at_freebsd.org>; "Borja 
Marcos" <borjam_at_sarenet.es>; <freebsd-current_at_freebsd.org>
Sent: Wednesday, October 16, 2013 3:10 PM
Subject: Re: ZFS secondarycache on SSD problem on r255173


> Yes
>
> We have 15 servers, all of them have problem while using with patch fo ashift, sh we rollback path (for r255173)
> and all of them works for a week without that's problem's. Yesterday one of of servers was updated to stable/10 (beta1)
>
> wich include patch  and after around 12 hours of works l2arc begin et errors like that
>
> kstat.zfs.misc.arcstats.l2_cksum_bad
> kstat.zfs.misc.arcstats.l2_io_error
>
>
> For now patch disabled in ower production.
>
>
> Please note we have very heavy load on zfs pool so 90GB arc and 3x180Gb L2arc have very big hit's on it  on it.
>
>
> SSD used for cache's is intel ssd 530 series smart for all devices in in normal states's
> no bad values on it.
>
> Steven Hartland wrote:
> SH> Have you confirmed the ashift changes are the actual cause of this
> SH> by backing out just those changes and retesting on the same hardware.
> SH>
> SH> Also worth checking your disks smart values to confirm there are no
> SH> visible signs of HW errors.
> SH>
> SH>     Regards
> SH>     Steve
> SH>
> SH> ----- Original Message ----- 
> SH> From: "Vitalij Satanivskij" <satan_at_ukr.net>
> SH> To: "Dmitriy Makarov" <supportme_at_ukr.net>
> SH> Cc: "Steven Hartland" <killing_at_multiplay.co.uk>; "Justin T. Gibbs" <gibbs_at_freebsd.org>; "Borja Marcos" <borjam_at_sarenet.es>;
> SH> <freebsd-current_at_freebsd.org>
> SH> Sent: Wednesday, October 16, 2013 9:01 AM
> SH> Subject: Re: ZFS secondarycache on SSD problem on r255173
> SH>
> SH>
> SH> > Hello.
> SH> >
> SH> > Patch brocke cache functionality.
> SH> >
> SH> > Look at's Dmitriy's mail from  Mon, 07 Oct 2013 21:09:06 +0300
> SH> >
> SH> > With subject ZFS L2ARC - incorrect size and abnormal system load on r255173
> SH> >
> SH> > As patch alredy in head and BETA it's not good.
> SH> >
> SH> > Yesterday we update one machine up to beta1 and forgot about patch. So 12 Hours and cache broken... :((
> SH> >
> SH> >
> SH> >
> SH> > Dmitriy Makarov wrote:
> SH> > DM> The attached patch by Steven Hartland fixes issue for me too. Thank you!
> SH> > DM>
> SH> > DM>
> SH> > DM> --- Исходное сообщение --- 
> SH> > DM> От кого: "Steven Hartland" < killing_at_multiplay.co.uk >
> SH> > DM> Дата: 18 сентября 2013, 01:53:10
> SH> > DM>
> SH> > DM> ----- Original Message ----- 
> SH> > DM> From: "Justin T. Gibbs" <
> SH> > DM>
> SH> > DM> --- 
> SH> > DM> Дмитрий Макаров
> SH> > DM> _______________________________________________
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> SH> > DM> http://lists.freebsd.org/mailman/listinfo/freebsd-current
> SH> > DM> To unsubscribe, send any mail to "freebsd-current-unsubscribe_at_freebsd.org"
> SH> >
> SH>
> SH>
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