Does Asus AC1900P with merlin supports Trim command?

[chu]

I have a USB flash disk supports TRIM command, i wanna to know does merlin supports TRIM command via USB 3.0 port with my USB flash disk?

 

[ColinTaylor]

No.

EDIT: Well, it didn't the last time I looked. It would depend in part on the filesystem you are using. Try mounting your filesystem with "-o discard" and see if it works.

 

[ColinTaylor]

Well call me surprised, but it appears to work!

# mount /dev/sda1 /tmp/mnt/VERBATIM -o discard
# mount | grep sda1
/dev/sda1 on /tmp/mnt/VERBATIM type ext4 (rw,relatime,barrier=1,data=ordered,discard)

Whether it actually does anything is another question.

 

[chu]

Well call me surprised, but it appears to work!

# mount /dev/sda1 /tmp/mnt/VERBATIM -o discard
# mount | grep sda1
/dev/sda1 on /tmp/mnt/VERBATIM type ext4 (rw,relatime,barrier=1,data=ordered,discard)

Whether it actually does anything is another question.

I try to use fstrim command on merlin but said "not found"

with -o discard means supports trim?

 

[chu]

and i saw this topic:
"In order to optimize the performance of the SSD, I strongly advise you to avoid doing the TRIM operation in real time (whenever a file is deleted) because you would be putting an unnecessary extra amount of work over the SSD. In other words: You should not enable the discard option in fstab.
Instead, what I recommend is to run a script periodically to tell the SSD which blocks are free with the command fstrim. Doing this operation daily or weekly is more than enough. This way we do not lose any performance due to TRIM when deleting files and we periodically keep informed the SSD about the free blocks."

http://blog.toracat.org/2014/07/discard-that-discard-run-fstrim-on-rhel-and-rebuilds/

 

[ColinTaylor]

-o discard performs trim in realtime.

https://www.reddit.com/r/archlinux/comments/1jhed8/fstrim_necessary_with_discard/

 

[chu]

-o discard performs trim in realtime.

https://www.reddit.com/r/archlinux/comments/1jhed8/fstrim_necessary_with_discard/

but router mount my usb flash disk automatically, how can i use the -o discard param?

 

[ColinTaylor]

Maybe use init-start and fstab.

https://github.com/RMerl/asuswrt-merlin/wiki/Custom-config-files

 

[chu]

Maybe use init-start and fstab.

https://github.com/RMerl/asuswrt-merlin/wiki/Custom-config-files

do you know how to let merlin supporting "fstrim" command? i would like to use fstrim via cron job

 

[ColinTaylor]

do you know how to let merlin supporting "fstrim" command? i would like to use fstrim via cron job

I think you would have to compile your own version of the firmware that includes the fstrim command. Set the busybox CONFIG_FSTRIM compile option.

Alternatively you could install entware-ng and use blkdiscard instead but the filesystem must be unmounted to use it.

 

[chu]

I think you would have to compile your own version of the firmware that includes the fstrim command. Set the busybox CONFIG_FSTRIM compile option.

Alternatively you could install entware-ng and use blkdiscard instead but the filesystem must be unmounted to use it.

I see, thank you ColinTaylor!