Install KaOS on SSD using Btrfs
Explanations how and why to use BTRFS
What is Btrfs?
Btrfs is a new copy on write (CoW) filesystem for Linux aimed at implementing advanced features while focusing on fault tolerance, repair and easy administration. Jointly developed at Oracle, Red Hat, Fujitsu, Intel, SUSE, STRATO and many others, Btrfs is licensed under the GPL and open for contribution from anyone.
- It is possible to dynamically resize mounted filesystems
- filesystems can span physical volumes, with optional RAID support
- physical volumes can be added to and removed from mounted filesystems
- compression option
- snapshots (including read-only and read-write) and seeds
- has a mode that is optimized for solid-state drives
Format as BTRFS
Current installer is ready to create Btrfs partitions so you can use it without any further instructions.
In case you want to fine tune the default setting used by the installer for fstab, you can use the following example:
$ kdesu kate /etc/fstab
And edit until it looks like this.
UUID=YOUROWNUUID / btrfs rw,noatime,compress=lzo,ssd,discard,space_cache,inode_cache 0 1 tmpfs /tmp tmpfs defaults,noatime,mode=1777 0 0 tmpfs /var/spool tmpfs defaults,noatime,mode=1777 0 0 tmpfs /var/tmp tmpfs defaults,noatime,mode=1777 0 0
- rw - Partition is mounted in read-write mode
- noatime - Don’t update inode access times on the filesystem. Can help performance
- compress=lzo - Data compression enable
- Discard - Optional if you already use ssd option, enable TRIM.
All others options optimize cache and send temps to RAM.
Verify if your SSD is align using
$ sudo blockdev --getalignoff /dev/sda4
if the result is 0 then your SSD is correctly aligned.
Creating a snapshot
# mount /media/btrfs # cd /media/btrfs # btrfs subvolume snapshot root root_snapshot_2011_01_11 # cd ~ # umount /media/btrfs
Rolling back a snapshot
# mount /media/btrfs # umount /home # mount -o defaults,subvol=home_snapshot_A /dev/sda /home # btrfs subvolume delete /media/btrfs/home # optional; this is so the # mv /media/btrfs/home_snapshot_A /media/btrfs/home # /etc/fstab need not change. # umount /media/btrfs