Advantages of FFS2 for /home on OpenBSD

[drm]

Hi!

As i want to switch my desktop pc to openbsd soon, i have some questions regarding ffs2. The FAQ says, that ffs2 will be chosen automatically if the slice is bigger than 1TiB. All the 'standard' slices like /, /usr, /var and /tmp are ffs by default, but for /home i wondered if there is a difference between ffs and ffs2. In my case, /home will only be around 800 GiB and it will used mostly for flacs (20-40 MiB each). Are there any advantages using ffs2? Should i tweak the standard parameters for fsize, bsize? And if i would use it, should i just do a

# newfs -O 2 sd0X
# reboot

after the installation completed? Thanks in advance!

Best,
drm

[jggimi]

Yes, that would be the command. However I don't believe you will have any particular advantage to using FFS2 for your use case, as there is no additional functionality.

--

Time for fsck(8) on boot up may be a concern, as the partition is so large. I mark large non-critical partitions like these with no fsck in fstab(8), and then check to see if they mounted in /etc/rc.local in order to execute fsck(8) in the event the mounts failed. For example, in one of my systems I have a 750GB drive with a single filesystem on it, and in that system's /etc/fstab:

bec2b3983466e45c.d /tomb ffs rw,softdep,nodev,nosuid 1 0

and in /etc/rc.local

# background fsck /tomb if required then mount.
df | grep -q tomb || (echo fscking /tomb; fsck -p /tomb;mount /tomb) &

[drm]

Hi jggimi!

Thanks for your answer. If i get it right, with your approach you can use your 'vital' partitions -- such as /home -- right after they're fscked at boot, while e.g. /multimedia is beeing repaired in the background? Maybe i will just create a separate slice for my music files and mount it read-only by default, so that there should be no need to fsck it at boot.

Then, my /home would be around 80 GiB. Does FFS2 support faster fsck-times? Or is it really just about supporting lager disks? That still is not totally clear to me.

Thanks and best regards,
drm

[jggimi]

If i get it right...

You did.

Does FFS2 support faster fsck-times? Or is it really just about supporting lager disks?

It's really about the larger disks. My 750GB partition is FFS, not FFS 2.

[drm]

Ok, now i got it. Thanks