I have two OCZ-AGILITY3 60 GB SSD drives with ext4 file systems. I bought the second one a few weeks after the first one. I have read some threads about SSD and trim=discard on this forum, and I have looked for information at the internet too
Here they write that sometimes on new SSD drives, the data are not zeroised, so it is hard to know if trim works
Here discard is discarded in favour of a cron job with fstrim (or manually)
http://http://www.webupd8.org/2013/0...te-drives.htmlCode:sudo fstrim -v / >> $LOG
I'm confused, and need help to understand.
I tried to tweak the first drive according to some web page (changing the cylinders, heads and sectors). But it didn't perform better than in the delivered state, similar to what is typically created by gparted, so I tried to change it back and have been using it for some months now. I didn't do any tweaking with the second drive, and until now, I have seen no difference.
I have enabled discard in /etc/fstab and it seems to work, does not complain and indicates that it is active in /etc/mtab, I have also booted from another drive and tested with manual mounting with and without the discard option.
I tested if discard works: I made a file, deleted it and checked the data on the drive space with hdparm. The drives are different ! The first one (that I tweaked and [tried to] reset) shows zeros after delete and sync, but the other one keeps the written data.
I have also tested fstrim on the drive that is not zeroised
With discard enabled it did nothing. Without discard enabled it reportedCode:sudo fstrim -v /
- Do you think that discard works also on this drive?Code:/mnt: 19918028800 bytes were trimmed
- Do you think that fstrim works on this drive?
- What do you recommend?
. discard or
. cron job with fstrim