From: Xen <list@xenhideout.nl>
To: linux-lvm@redhat.com
Subject: Re: [linux-lvm] cache on SSD makes system unresponsive
Date: Fri, 20 Oct 2017 08:46:02 +0200 [thread overview]
Message-ID: <20caebee6f708ec9180ba192d6001d39@xenhideout.nl> (raw)
In-Reply-To: <541215543.377417.1508458336923@mail.yahoo.com>
matthew patton schreef op 20-10-2017 2:12:
>> It is just a backup server,
>
> Then caching is pointless.
That's irrelevant and not up to another person to decide.
> Furthermore any half-wit caching solution
> can detect streaming read/write and will deliberately bypass the
> cache.
The problem was not performance, it was stability.
> Furthermore DD has never been a useful benchmark for anything.
> And if you're not using 'odirect' it's even more pointless.
Performance was not the issue, stability was.
>> Server has 2x SSD drives by 256Gb each
>
> and for purposes of 'cache' should be individual VD and not waste
> capacity on RAID1.
Is probably also going to be quite irrelevant to the problem at hand.
>> 10x 3Tb drives. In addition there are two
>> MD1200 disk arrays attached with 12x 4Tb disks each. All
>
> Raid5 for this size footprint is NUTs. Raid6 is the bare minimum.
That's also irrelevant to the problem at hand.
next prev parent reply other threads:[~2017-10-20 6:46 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <541215543.377417.1508458336923.ref@mail.yahoo.com>
2017-10-20 0:12 ` [linux-lvm] cache on SSD makes system unresponsive matthew patton
2017-10-20 6:46 ` Xen [this message]
2017-10-20 9:59 ` Oleg Cherkasov
[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
2017-10-19 17:54 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
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
-- strict thread matches above, loose matches on Subject: below --
2017-10-19 10:05 Oleg Cherkasov
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