From: Oleg Cherkasov <o1e9@member.fsf.org>
To: linux-lvm@redhat.com
Subject: Re: [linux-lvm] cache on SSD makes system unresponsive
Date: Sat, 21 Oct 2017 16:10:36 +0200 [thread overview]
Message-ID: <6897ab24-f558-33c6-511a-5d2bc3f4967b@member.fsf.org> (raw)
In-Reply-To: <20171021025459.GD31049@redhat.com>
On 21. okt. 2017 04:55, Mike Snitzer wrote:
> On Thu, Oct 19 2017 at 5:59pm -0400,
> Oleg Cherkasov <o1e9@member.fsf.org> wrote:
>
>> On 19. okt. 2017 21:09, John Stoffel wrote:
>>>
>
> So aside from SAR outout: you don't have any system logs? Or a vmcore
> of the system (assuming it crashed?) -- in it you could access the
> kernel log (via 'log' command in crash utility.
Unfortunately no logs. I have tried to see if I may recover dmesg
however no luck. All logs but the latest dmesg boot are zeroed. Of
course there are messages, secure and others however I do not see any
valuable information there.
System did not crash, OOM were going wind however I did manage to
Ctrl-Alt-Del from the main console via iLO so eventually it rebooted
with clean disk umount.
>
> More specifics on the workload would be useful. Also, more details on
> the LVM cache configuration (block size? writethrough or writeback?
> etc).
No extra params but specifying mode writethrough initially. Hardware
RAID1 on cache disk is 64k and on main array hardware RAID5 128k.
I had followed precisely documentation from RHEL doc site so lvcreate,
lvconvert to update type and then lvconvert to add cache.
I have decided to try writeback after and shifted cachemode to it with
lvcache.
>
> I'll be looking very closely for any sign of memory leaks (both with
> code inspection and testing while kemmleak is enabled).
>
> But the more info you can provide on the workload the better.
According to SAR there are no records about 20min before I reboot, so I
suspect SAR daemon failed a victim of OOM.
next prev parent reply other threads:[~2017-10-21 14:10 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-19 17:54 [linux-lvm] cache on SSD makes system unresponsive Oleg Cherkasov
2017-10-19 18:13 ` Xen
2017-10-20 10:21 ` Oleg Cherkasov
2017-10-20 10:38 ` Xen
2017-10-20 11:41 ` Oleg Cherkasov
2017-10-19 18:49 ` Mike Snitzer
2017-10-20 11:07 ` Joe Thornber
2017-10-19 19:09 ` John Stoffel
2017-10-19 19:46 ` Xen
2017-10-19 21:14 ` John Stoffel
2017-10-20 6:42 ` Xen
2017-10-19 21:59 ` Oleg Cherkasov
2017-10-20 19:35 ` John Stoffel
2017-10-21 3:05 ` Mike Snitzer
2017-10-21 14:33 ` Oleg Cherkasov
2017-10-23 10:58 ` Zdenek Kabelac
2017-10-21 2:55 ` Mike Snitzer
2017-10-21 14:10 ` Oleg Cherkasov [this message]
2017-10-23 20:45 ` John Stoffel
2017-10-20 16:20 ` lejeczek
2017-10-20 16:48 ` Xen
2017-10-20 17:02 ` Bernd Eckenfels
2017-10-24 14:51 ` lejeczek
[not found] <640472762.2746512.1508882485777.ref@mail.yahoo.com>
2017-10-24 22:01 ` matthew patton
2017-10-24 23:10 ` Chris Friesen
[not found] <1928541660.2031191.1508802005006.ref@mail.yahoo.com>
2017-10-23 23:40 ` matthew patton
2017-10-24 15:36 ` Xen
[not found] <1714773615.1945146.1508792555922.ref@mail.yahoo.com>
2017-10-23 21:02 ` matthew patton
2017-10-23 21:54 ` Xen
2017-10-24 2:51 ` John Stoffel
[not found] <1540708205.1077645.1508602122091.ref@mail.yahoo.com>
2017-10-21 16:08 ` matthew patton
[not found] <1244564108.1073508.1508601932111.ref@mail.yahoo.com>
2017-10-21 16:05 ` matthew patton
2017-10-24 18:09 ` Oleg Cherkasov
[not found] <541215543.377417.1508458336923.ref@mail.yahoo.com>
2017-10-20 0:12 ` matthew patton
2017-10-20 6:46 ` Xen
2017-10-20 9:59 ` Oleg Cherkasov
-- strict thread matches above, loose matches on Subject: below --
2017-10-19 10:05 Oleg Cherkasov
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