G-Technology G-RACK 12, User Manual

Page: 258 / 296

F.A.Q.
p. 258
Comparison of features between the most popular file system ext4.
BTRfs vs ext4
ext4 and BTRfs are modern file system types which can be used with a Linux operating system.
ext4 advantages
ext4 is the default for major Linux distributions such as Ubuntu. ext4 is in use by a very large number
of Linux users and has proven to be useable. BTRfs is not considered ready for normal (production)
use, and has not been widely tested by end users. One of the primary problems with BTRfs today
is its incomplete fsck (filesystem check) implementation, which may not be able to successfully fix
file system problems when they appear. (According to the BTRfs wiki as of 2012/7/3, «while this
tool should be able to repair broken filesystems, it is still relatively new code, and has not seen
widespread testing on a large range of real-life breakage. It is possible that it may cause additional
damage in the process of repair.»)
Benchmarks have shown that ext4 provides superior read-write speed to BTRfs. Since BTRfs is under
development, it may (or may not) improve performance to match ext4 in the future. BTRfs has
shown high disk consumption on small files.
BTRfs advantages
BTRfs will provide new features, such as the «copy-on-write» concept to improve performance and
reliability. BTRfs systems will be able to «roll back», meaning all changes made to the hard disk since
a certain point in time would be reversed.
BTRfs and ext4 both support online grow, but BTRfs supports online shrink, while ext4 only supports
offline shrink. This means BTRfs users do not have to unmount the filesystem to shrink it.
The way to the future
Theodore Ts›o, principal developer of ext3 and a maintainer of ext4, says that BTRfs is the way
forward due to new features in its design.
Public Opinion from /r/BTRfs on reddit.
Love:
• Online everything! Dedup, defrag, shrink, grow, raid level migration, adding/removing drives.
Think about this: you can move the root partition to a different drive without rebooting.
• Snapshots. I use these every day, and sometimes when I use them they›re a lifesaver.
• Send/receive. In combination with Snapshots an über awesome base to build a backup system.
• Checksumming. I have lost data in the past to bit rot and I don’t want it to happen again.