Gentoo Archives: gentoo-user

From: Eray Aslan <eray.aslan@×××××××.tr>
To: gentoo-user@l.g.o
Subject: Re: Tweaks for SSDs [Was: [gentoo-user] [ot] no more inodes]
Date: Sat, 30 May 2009 19:25:35
Message-Id: 20090530192529.GE5826@zptr-nb01
In Reply to: Re: Tweaks for SSDs [Was: [gentoo-user] [ot] no more inodes] by Neil Bothwick
1 On Sat, May 30, 2009 at 02:40:34PM +0100, Neil Bothwick wrote:
2 > On Sat, 30 May 2009 12:06:04 +0200, Florian Philipp wrote:
3 >
4 > > Delaying commits with ext4 and/or laptop-mode will reduce the wear-down
5 > > of your SSD but it might as well freeze your system when the actual
6 > > commit takes place because these things tend to have a terribly low
7 > > write performance.
8 >
9 > That may explain the pauses I get from time to time. Maybe shortening the
10 > commit period will help.
11
12 Couple of points regarding the pauses, SSDs, schedulers and ext3/ext4:
13
14 * try ext4 with its delayed allocation. It should help with pauses
15 * ext3 with data=writeback should help. Some security implications with
16 data=writeback tho. So be careful if it is not a single user machine.
17 * Deadline scheduler has more throughput than CFQ or anticipatory but it
18 is totally unusable under load
19 * A lot of patches to ext3 and ext4 for a/m pauses and SSDs. Some made
20 it to kernel 2.6.30 I believe.
21 * Try CFQ and NOOP as schedulers for SSDs for now. After the above
22 patches, CFQ should be the better choice.
23
24 Basically, a lot of changes to ext3/ext4 and schedulers at the moment.
25 I would wait for at least kernel 2.6.31 before trying alternatives and
26 making decisions.
27
28 > Or I could try btrfs, which has an ssd mount option.
29
30 Ugh. Even on-disk format is not finalized yet.
31
32 --
33 Eray

Replies

Subject Author
Re: Tweaks for SSDs [Was: [gentoo-user] [ot] no more inodes] Neil Bothwick <neil@××××××××××.uk>