On Sat, Nov 14, 2020 at 03:13:57PM +0100, Leo Unglaub wrote:
> Hey,
> my largest filesystem with OpenBSD on it is 12TB and for the minimal usecase
> i have it works fine. I did not loose any data or so. I have it mounted with
> the following flags:
>
> > local, noatime, nodev, noexec, nosuid, softdep
>
> The only thing i should mention is that one time the server crashed and i
> had to do a fsck during the next boot. It took around 10 hours for the 12TB.
> This might be something to keep in mind if you want to use this on a server.
> But if my memory serves me well otto did some changes to fsck on ffs2, so
> maybe thats a lot faster now.
>
> I hope this helps you a little bit!
> Greetings from Vienna
> Leo
>
> Am 14.11.2020 um 13:50 schrieb Mischa:
> > I am currently in the process of building a large filesystem with
> > 12 x 6TB 3.5" SAS in raid6, effectively ~55TB of storage, to serve as a
> > central, mostly download, platform with around 100 concurrent
> > connections.
> >
> > The current system is running FreeBSD with ZFS and I would like to
> > see if it's possible on OpenBSD, as it's one of the last two systems
> > on FreeBSD left.:)
> >
> > Has anybody build a large filesystem using FFS2? Is it a good idea?
> > How does it perform? What are good tests to run?
> >
> > Your help and suggestions are really appriciated!
>
It doesn't always has to be that bad, on current:
[otto@lou:22]$ dmesg | grep sd[123]
sd1 at scsibus1 targ 2 lun 0: <ATA, ST16000NE000-2RW, EN02> naa.5000c500c3ef0896
sd1: 15259648MB, 512 bytes/sector, 31251759104 sectors
sd2 at scsibus1 targ 3 lun 0: <ATA, ST16000NE000-2RW, EN02> naa.5000c500c40e8569
sd2: 15259648MB, 512 bytes/sector, 31251759104 sectors
sd3 at scsibus3 targ 1 lun 0: <OPENBSD, SR RAID 0, 006>
sd3: 30519295MB, 512 bytes/sector, 62503516672 sectors
[otto@lou:20]$ df -h /mnt
Filesystem Size Used Avail Capacity Mounted on
/dev/sd3a 28.9T 5.1G 27.4T 0% /mnt
[otto@lou:20]$ time doas fsck -f /dev/rsd3a
** /dev/rsd3a
** File system is already clean
** Last Mounted on /mnt
** Phase 1 - Check Blocks and Sizes
** Phase 2 - Check Pathnames
** Phase 3 - Check Connectivity
** Phase 4 - Check Reference Counts
** Phase 5 - Check Cyl groups
176037 files, 666345 used, 3875083616 free (120 frags, 484385437
blocks, 0.0% fragmentation)
1m47.80s real 0m14.09s user 0m06.36s system
But note that fsck for FFS2 will get slower once more inodes are in
use or have been in use.
Also, creating the fs with both blockszie and fragment size of 64k
will make fsck faster (due to less inodes), but that should only be
done if the files you are going to store ar relatively big (generally
much bigger than 64k).
As for the speed of general operation, I wouldn't know. I never used
such large firessytems for anything other than archive storage. The fs
above I only have been using for filesystem dev work.
-Otto
