From: Roman Mamedov <rm@romanrm.ru>
To: "Fajar A. Nugraha" <list@fajar.net>
Cc: linux-btrfs <linux-btrfs@vger.kernel.org>
Subject: Re: fstrim on BTRFS
Date: Thu, 29 Dec 2011 10:37:36 +0600 [thread overview]
Message-ID: <20111229103736.26a3a07d@natsu> (raw)
In-Reply-To: <CAG1y0se+ctBx0YpsCGaW-8TKEN7PZix7PA8Eu-FzfVtkNPkkUQ@mail.gmail.com>
[-- Attachment #1: Type: text/plain, Size: 1231 bytes --]
On Thu, 29 Dec 2011 11:21:14 +0700
"Fajar A. Nugraha" <list@fajar.net> wrote:
> Slightly off-topic, how useful would trim be for btrfs when using
> newer SSD which have their own garbage collection and wear leveling
> (e.g. sandforce-based)?
>
> I'm trying fstrim and my disk is now pegged at write IOPS. Just
> wondering if maybe a "btrfs fi balance" would be more useful, since:
> - with trim, used space will remain used. Thus future writes will only
> utilized space marked as "free", making them wear faster
> - with "btrfs fi balance", btrfs will move the data around so (to some
> degree) the currently-unused space will be used, and currently-used
> space will be unused, which will improve wear leveling.
Modern controllers (like the SandForce you mentioned) do their own wear leveling 'under the hood', i.e. the same user-visible sectors DO NOT neccessarily map to the same locations on the flash at all times; and introducing 'manual' wear leveling by additional rewriting is not a good idea, it's just going to wear it out more.
--
With respect,
Roman
~~~~~~~~~~~~~~~~~~~~~~~~~~~
"Stallman had a printer,
with code he could not see.
So he began to tinker,
and set the software free."
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 198 bytes --]
next prev parent reply other threads:[~2011-12-29 4:37 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-28 16:57 fstrim on BTRFS Martin Steigerwald
2011-12-29 4:02 ` Li Zefan
2011-12-29 4:21 ` Fajar A. Nugraha
2011-12-29 4:32 ` Fajar A. Nugraha
2011-12-29 4:37 ` Roman Mamedov [this message]
2011-12-29 4:42 ` Fajar A. Nugraha
2011-12-29 5:29 ` cwillu
2011-12-29 10:52 ` Martin Steigerwald
2012-01-03 21:05 ` Chris Mason
2011-12-29 4:29 ` Fajar A. Nugraha
2011-12-29 9:39 ` Li Zefan
2011-12-29 9:52 ` Fajar A. Nugraha
2011-12-30 6:19 ` Li Zefan
2011-12-30 6:35 ` Fajar A. Nugraha
-- strict thread matches above, loose matches on Subject: below --
2014-10-31 0:21 Noah Massey
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20111229103736.26a3a07d@natsu \
--to=rm@romanrm.ru \
--cc=linux-btrfs@vger.kernel.org \
--cc=list@fajar.net \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.