From: Joe Thornber <thornber@redhat.com>
To: LVM general discussion and development <linux-lvm@redhat.com>
Subject: Re: [linux-lvm] lvmcache performance
Date: Mon, 8 Feb 2016 09:17:06 +0000 [thread overview]
Message-ID: <20160208091705.GA1612@rh-vpn> (raw)
In-Reply-To: <87a8nctl7x.fsf@vostro.rath.org>
On Sun, Feb 07, 2016 at 10:43:30AM -0800, Nikolaus Rath wrote:
> Is that the wrong expectation? But even then, shouldn't I at least see
> some improvement?
Firstly, if you have the latest software, I suggest you switch to the
smq cache policy which is generally out performing the old mq policy
substantially.
Secondly, I think you may need to reset your expectations a bit.
dm-cache is a slow moving cache. It monitors IO, detectings hotspots
on the disk and then 'promotes' those regions to the SSD. You may
find that the reads that occur during a boot, occur only infrequently
once the system is booted.
- Joe
next prev parent reply other threads:[~2016-02-08 9:17 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-07 18:43 [linux-lvm] lvmcache performance Nikolaus Rath
2016-02-08 9:17 ` Joe Thornber [this message]
2016-02-08 16:51 ` John Stoffel
2016-02-08 22:05 ` Nikolaus Rath
2016-02-09 9:39 ` Mateusz Korniak
2016-02-08 22:05 ` Nikolaus Rath
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