On 15 Nov at 13:04, Otto Moerbeek <o...@drijf.net> wrote: > On Sat, Nov 14, 2020 at 05:59:37PM +0100, Otto Moerbeek wrote: > > > On Sat, Nov 14, 2020 at 04:59:22PM +0100, Mischa wrote: > > > > > On 14 Nov at 15:54, Otto Moerbeek <o...@drijf.net> wrote: > > > > 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). > > > > > > Good to know. This will be mostly large files indeed. > > > That would be "newfs -i 64"? > > > > Nope, newfs -b 65536 -f 65536 > > To clarify: the default block size for large filesystems is already > 2^16, but this value is taken from the label, so if another fs was on > that partition before, it might have changed. The default fragsize is > blocksize/8. When not specified on the command line, it is also taken > from the label. > > Inode density is derived from the number of frgaments (normally 1 > inoder per 4 fragments), if you increase framgent size, the number of > fragments drops and so the number if inodes. > > A fragment is the minimal alloctation unit. So if you have lots of > small files you will waste a lot of space and potentially run out of > inodes. You only want to increase fragment size of you mostly store > large files.
This is for large files only. 16 partitions: # size offset fstype [fsize bsize cpg] a: 117199339520 0 4.2BSD 65536 65536 52270 # /data c: 117199339520 0 unused The new FS now has: new# df -hi /data Filesystem Size Used Avail Capacity iused ifree %iused Mounted on /dev/sd1a 54.5T 64.0K 51.8T 0% 1 229301757 0% /data The server I am replacing has: old# df -hi /data Filesystem Size Used Avail Capacity iused ifree %iused Mounted on data 35T 34T 539G 98% 104k 1.1G 0% /data I guess we are good. :) Mischa
