From: David Brown <david.brown@hesbynett.no>
To: Bar Ziony <bartzy@gmail.com>
Cc: linux-raid@vger.kernel.org
Subject: Re: Does mdadm supports TRIM command to SSDs?
Date: Wed, 11 Jul 2012 13:27:43 +0200 [thread overview]
Message-ID: <4FFD632F.3060407@hesbynett.no> (raw)
In-Reply-To: <CAF-9JegPGmayAO0gAsqY4J3rpRpTq_ciLA5e+nu0PsSjJhwr-A@mail.gmail.com>
On 07/11/2012 12:55 AM, Bar Ziony wrote:
> Hi,
>
> I wasn't able to find any information about it after searching for
> hours - Does mdadm supports sending the TRIM command to SSDs, if using
> the right filesystem with the 'discard' flag?
> If it does support it, from what kernel version it is?
>
> Thank you,
> Bar.
The big question here is /why/ would you want TRIM support? In many
circumstances it leads to slower operations, and for SSDs from the past
couple of years it is almost entirely superseded by the SSD's own
garbage collection.
So while there certainly has been some work done on TRIM and md raid, it
is not a priority as it is of questionable benefit. You might find some
operations are a little faster for older SSDs if you use TRIM, but your
metadata operations will be a lot slower.
Your best bet is just to make sure you only buy SSDs that are at least
half decent, and don't worry about TRIM.
next prev parent reply other threads:[~2012-07-11 11:27 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-10 22:55 Does mdadm supports TRIM command to SSDs? Bar Ziony
2012-07-11 0:43 ` Igor M Podlesny
2012-07-11 1:08 ` Igor M Podlesny
2012-07-11 7:59 ` Bar Ziony
2012-07-11 11:27 ` David Brown [this message]
2012-07-11 11:49 ` Bar Ziony
2012-07-11 14:54 ` David Brown
[not found] ` <CAA8Hn0eWuHJy9ivmvUVc-m=2t+L2_ACTy52tGVOYnFy97XFTXA@mail.gmail.com>
2012-07-11 15:08 ` David Brown
2012-07-11 16:21 ` Bernd Schubert
2012-07-11 16:22 ` Bar Ziony
2012-07-11 16:44 ` Bernd Schubert
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