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From: Jarkko Oranen <oranenj@iki.fi>
To: linux-lvm@redhat.com
Subject: [linux-lvm] Does LVM RAID1 have TRIM support?
Date: Sun, 24 Aug 2014 19:08:17 +0300	[thread overview]
Message-ID: <1408896497.27190.12.camel@kurenai.local> (raw)

Hello

Yesterday I experimented a bit with my RAID configuration on a pair of
SSDs, and it seems that LVM's native RAID does not have TRIM support...
At least, when I try to run fstrim manually, it complains even though
issue_discards is enabled. Plain LVs on top of an MD RAID PV do work, of
course.

Am I perhaps missing some configuration, or do RAID1 logical volumes
simply not have support for TRIM yet? I'm running a fairly recent kernel
(3.15.8) and lvm version says this:

  LVM version:     2.02.106(2) (2014-04-10)
  Library version: 1.02.85 (2014-04-10)
  Driver version:  4.27.0

As an aside, can anyone point me to documentation or other resources
about the pros and cons of LVM native RAID1 setup (which I understand
uses MD RAID internally?) vs. MD RAID PV + LVM. It seems I might be able
to save some SSD space and only mirror the LVs I actually need to keep
safe from crashes.

--
Jarkko Oranen

             reply	other threads:[~2014-08-24 16:08 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-08-24 16:08 Jarkko Oranen [this message]
2014-09-02 21:49 ` [linux-lvm] Does LVM RAID1 have TRIM support? Brassow Jonathan
2014-09-04 11:06   ` Jarkko Oranen
2014-09-08 17:47     ` Brassow Jonathan
2014-09-08 18:47       ` Jarkko Oranen
2014-09-11 23:31         ` Brassow Jonathan
2014-09-12  7:24           ` Jarkko Oranen
2014-09-24  4:17             ` Brassow Jonathan

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