From: Gionatan Danti <g.danti@assyoma.it>
To: LVM general discussion and development <linux-lvm@redhat.com>
Cc: Ilia Zykov <mail@izyk.ru>
Subject: Re: [linux-lvm] Why doesn't the lvmcache support the discard (trim) command?
Date: Fri, 19 Oct 2018 22:54:26 +0200 [thread overview]
Message-ID: <17a367c7043400e4890738b00afcb011@assyoma.it> (raw)
In-Reply-To: <c6043f6f-f10a-5e6f-19ba-b50508e48ee0@redhat.com>
Il 19-10-2018 15:08 Zdenek Kabelac ha scritto:
> Hi
>
> It's rather about different workload takes benefit from different
> caching approaches.
>
> If your system is heavy on writes - dm-writecache is what you want,
> if you mostly reads - dm-cache will win.
>
> That's why there is dmstats to also help identify hotspots and overal
> logic.
> There is nothing to win always in all cases - so ATM 2 different
> targets are provided - NVDIMMs already seems to change game a lot...
>
> dm-writecache could be seen as 'extension' of your page-cache to held
> longer list of dirty-pages...
>
> Zdenek
Thanks for these information. Reading a bit the commit which provide
dm-writeback, it seems a sort of "L2 pagecache", right? It should be
*very* interesting for use with NVDIMMs and/or fast NVME devices...
Regards.
--
Danti Gionatan
Supporto Tecnico
Assyoma S.r.l. - www.assyoma.it
email: g.danti@assyoma.it - info@assyoma.it
GPG public key ID: FF5F32A8
prev parent reply other threads:[~2018-10-19 20:54 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-18 22:56 [linux-lvm] Why doesn't the lvmcache support the discard (trim) command? Ilia Zykov
2018-10-19 9:12 ` Zdenek Kabelac
2018-10-19 9:42 ` Gionatan Danti
2018-10-19 9:49 ` Zdenek Kabelac
2018-10-19 9:55 ` Ilia Zykov
2018-10-19 10:58 ` Zdenek Kabelac
2018-10-19 12:45 ` Gionatan Danti
2018-10-19 13:08 ` Zdenek Kabelac
2018-10-19 13:16 ` Ilia Zykov
2018-10-19 17:00 ` Ilia Zykov
2018-10-22 10:54 ` Zdenek Kabelac
2018-10-19 20:54 ` Gionatan Danti [this message]
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