About default fstab options in ISO

Support
1

I just installed Manjaro a SSD using the full disk install option and noticed that the fstab options had significantly changed.
From 21.1.x:

UUID=yyyy-yyyy                            /boot/efi      vfat    umask=0077 0 2
UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx /              btrfs   subvol=/@,defaults,noatime,space_cache,autodefrag,compress=zstd,discard=async,ssd,commit=120 0 0
UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx /home          btrfs   subvol=/@home,defaults,noatime,space_cache,autodefrag,compress=zstd,discard=async,ssd,commit=120 0 0
UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx /var/cache     btrfs   subvol=/@cache,defaults,noatime,space_cache,autodefrag,compress=zstd,discard=async,ssd,commit=120 0 0
UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx /var/log       btrfs   subvol=/@log,defaults,noatime,space_cache,autodefrag,compress=zstd,discard=async,ssd,commit=120 0 0
UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxz swap           swap    defaults,noatime 0 0
tmpfs                                     /tmp           tmpfs   defaults,noatime,mode=1777 0 0

to the current:

UUID=yyyy-yyyy                           /boot/efi      vfat    umask=0077 0 2
UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx /              btrfs   subvol=/@,defaults,discard=async 0 0
UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx /home          btrfs   subvol=/@home,defaults,discard=async 0 0
UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx /var/cache     btrfs   subvol=/@cache,defaults,discard=async 0 0
UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx /var/log       btrfs   subvol=/@log,defaults,discard=async 0 0
UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxz swap           swap    defaults,noatime 0 0
tmpfs                                     /tmp           tmpfs   defaults,noatime,mode=1777 0 0

Is the removal of so many option including the ones like ssd, space_cache, commit gonna affect the performance of SSDs?

2

Some of this options are now obsolete, others discouraged :wink:
Please have a look at btrfs Wiki and Welcome to BTRFS documentation! — BTRFS documentation

3

btrfs - it is quite a decision - isn’t it?

And you are supposed to know - after all you did chose a non standard fs - btrfs

4

  1. I would recommend removing the discard mount option and use the fstrim.timer instead. Better for performance and better for your SSD.

  2. Remove the noatime mount option for the swap partition. It’s meaningless, because a swap partition doesn’t have any filesystem on it, and therefore no inodes, and therefore also no atime field that can be updated.