-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Herbert Graeber wrote:
Am Freitag 28 August 2009 16:17:43 schrieb Jeff Mahoney:
I did some performance testing with SSDs to gauge what factors are important in trying to tune for them. I've ignored parameters that will increase performance in all cases (noatime,nodiratime,etc) and focused on SSD-specific (and RAID) factors like striping and alignment.
There is an article by Theodore Ts'o about this:
http://thunk.org/tytso/blog/2009/02/20/aligning-filesystems-to-an-ssds-erase... block-size/
Yep, I read that around the time Ted wrote it. Then I ran across an open FATE entry on how to optimize file systems for SSDs. Other than btrfs, no file systems have options that are specifically for SSDs. XFS and ext4 (at least) have options for RAID controllers that can be leveraged, though.
The results, with a whopping two test devices, seem to indicate that alignment helps on low and high end devices while striping seems to help on low end devices. I'd be interested to hear how a larger cross section of devices perform. I'll also have results from LVM volumes later today. Since the placement of LVs can also affect alignment, it may be worth looking at as well.
As a consequence it would be nice to have support for formatting with H=224 and S=56 during installation. I have written a feature request for this:
https://features.opensuse.org/306337
Currently, to get such a formatting one has to partiion the SSD before installing on another machine or the same machine with the previous installed OS or rescue CD.
Yeah, that is definitely a pain. One of the major reasons I started the testing work was to come up with solid data as to why YaST should care about things like partition alignment when setting up the partition table. If the disk is already partitioned, it would be useful to be able to automatically align on 128k boundaries without changing the geometry. - -Jeff - -- Jeff Mahoney SUSE Labs -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org iEYEARECAAYFAkqYXRcACgkQLPWxlyuTD7K69ACeMTlNk5KHvCCMDsqawrz6ZR2z lyUAn0HuYowx+f3zM6Ewp1/ka1+e8Acj =yqVY -----END PGP SIGNATURE----- -- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-factory+help@opensuse.org