Re: weekly fstrim (still) necessary?

[Adam Borowski <kilobyte@angband.pl>]

On Sun, Jun 21, 2020 at 07:42:40AM +0200, Ulli Horlacher wrote:
> On SLES a weekly fstrim is done via a btrfsmaintenance script, which is
> missing on Ubuntu.
> 
> For ext4 filesystem an explicite fstrim call is no longer neccessary, what
> about btrfs?
> Shall I call fstrim via /etc/cron.weekly ?

Both ext4 and btrfs may or may not auto-discard in the write path, depending
on mount option.  A lot of disks handle such frequent small discards poorly
-- usually with a greatly decreased performance, although data loss in not
unknown.

If you test your disk and know that it is happy with tons of small discards,
then the discard mount option is good for you.  Otherwise, you want to do
large discards once in a while -- be it a day or a week.

Not discarding at all is a bad idea on most disks.


Meow!
-- 
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⣾⠁⢠⠒⠀⣿⡁ in the beginning was the boot and root floppies and they were good.
⢿⡄⠘⠷⠚⠋⠀                                       -- <willmore> on #linux-sunxi
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