[opensuse-factory] Btrfs SSD fstab settings
Hi folks, Just wondering if any of you have experience with btrfs file system and SSDs. What do you recommend by way of fstab settings/other measures, e.g. trim. I really can't remember what i had with my last ext4 installation, but probably added noatime and discard to fstab. Cheers, Trent p.s. I also suspect i don't need to make any changes from the default, my Samsung EVO 840 is pretty robust. But thought it worth asking. -- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-factory+owner@opensuse.org
On Tue, 4 Nov 2014 15:42, Cristian Rodríguez <crrodriguez@...> wrote:
Btrfs does check /sys/block/sdX/queue/rotational for hdd / sdd and sets its "ssd" option to default=on if the above gives back "0" (Zero), see: https://btrfs.wiki.kernel.org/index.php/Mount_options For discard / trim, well there are different opinions. For me, using "/usr/sbin/fstrim [options] /mount/point" via cron is the prefered solution, YMMV. Regarding noatime / relatime(default), the discusions where "spirited", but like with trim, there is no universal right or wrong. Keep one thing in mind: Btrfs is not the end all, best for all uses filesystem. Thinking for yourself beforehand is encouraged. - Yamaban.
On Tue, Nov 04, 2014 at 04:13:20PM +0100, Yamaban wrote:
Agreed, defaults for SSD should be OK.
https://btrfs.wiki.kernel.org/index.php/Mount_options
For discard / trim, well there are different opinions.
I don't think it's a matter of oppinion that much. Mounting with 'discard' may degrade performance on SATA devices prior to version 3.1 where the TRIM command is unqueued. This is mentioned on the page and elsewhere. The effects of TRIM also depend on the device itself and there are no guarantees that it will do anything.
For me, using "/usr/sbin/fstrim [options] /mount/point" via cron is the prefered solution, YMMV.
This is the recommended way and the period could be once per week or more, depending on the data change rate. In 13.2, there's a unified config file that allows to set the trim period, among others. The package is btrfsmaintenannce and the config is /etc/sysconfig/btrfsmaintenance . The defaults were set so it's not necessary to tune it before use. In case of trim it's weekly run on / . -- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-factory+owner@opensuse.org
On Tue, 4 Nov 2014 15:42, Cristian Rodríguez <crrodriguez@...> wrote:
Btrfs does check /sys/block/sdX/queue/rotational for hdd / sdd and sets its "ssd" option to default=on if the above gives back "0" (Zero), see: https://btrfs.wiki.kernel.org/index.php/Mount_options For discard / trim, well there are different opinions. For me, using "/usr/sbin/fstrim [options] /mount/point" via cron is the prefered solution, YMMV. Regarding noatime / relatime(default), the discusions where "spirited", but like with trim, there is no universal right or wrong. Keep one thing in mind: Btrfs is not the end all, best for all uses filesystem. Thinking for yourself beforehand is encouraged. - Yamaban.
On Tue, Nov 04, 2014 at 04:13:20PM +0100, Yamaban wrote:
Agreed, defaults for SSD should be OK.
https://btrfs.wiki.kernel.org/index.php/Mount_options
For discard / trim, well there are different opinions.
I don't think it's a matter of oppinion that much. Mounting with 'discard' may degrade performance on SATA devices prior to version 3.1 where the TRIM command is unqueued. This is mentioned on the page and elsewhere. The effects of TRIM also depend on the device itself and there are no guarantees that it will do anything.
For me, using "/usr/sbin/fstrim [options] /mount/point" via cron is the prefered solution, YMMV.
This is the recommended way and the period could be once per week or more, depending on the data change rate. In 13.2, there's a unified config file that allows to set the trim period, among others. The package is btrfsmaintenannce and the config is /etc/sysconfig/btrfsmaintenance . The defaults were set so it's not necessary to tune it before use. In case of trim it's weekly run on / . -- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-factory+owner@opensuse.org
participants (4)
-
Cristian Rodríguez -
David Sterba -
Trent Hawkins -
Yamaban