Subject: Re: Interesting disk/filesystem anomaly addendum
To: Bri <itai@replic.net>
From: Luke Mewburn <lukem@wasabisystems.com>
List: port-i386
Date: 12/27/2001 21:42:36
On Thu, Dec 27, 2001 at 12:44:30AM -0800, Bri wrote:
| dumpfs returns
|
| endian little-endian
| magic 11954 time Thu Dec 27 00:27:18 2001
| cylgrp dynamic inodes 4.4BSD fslevel 3 softdep enabled
| nbfree 2672921 ndir 87 nifree 24031062 nffree 954
| ncg 12114 ncyl 193821 size 97685784 blocks 94487482
| bsize 8192 shift 13 mask 0xffffe000
| fsize 1024 shift 10 mask 0xfffffc00
| frag 8 shift 3 fsbtodb 1
| cpg 16 bpg 1008 fpg 8064 ipg 1984
| minfree 5% optim time maxcontig 8 maxbpg 2048
| rotdelay 0ms headswitch 0us trackseek 0us rps 120
| ntrak 16 nsect 63 npsect 63 spc 1008
| symlinklen 60 trackskew 0 interleave 1 contigsumsize 8
| maxfilesize 0x0000400801017fff
| nindir 2048 inopb 64 nspf 2
| sblkno 16 cblkno 24 iblkno 32 dblkno 280
| sbsize 2048 cgsize 2048 offset 32 mask 0xfffffff0
| csaddr 280 cssize 194560 shift 9 mask 0xfffffe00
| cgrotor 9301 fmod 0 ronly 0 clean 0x02
|
| and then a bunch of stuff relating to cylinders and clusters. I can
| include that as well if you like, but I'm guessing it is going to be
| prohibitively large(I did not let it finish.)
That system has a *lot* of cylinder groups (12114) and a *lot* of
cylinders (193821), and is most likely triggering the afore-mentioned
pathological behaviour.
| I'll give current a shot, but I prefer to avoid it for this box, as any
| issues that it has are a large inconvenience.
You could run the latest NetBSD-1.5 branch code instead of -current,
which is currently known as "1.5.3_ALPHA" and should eventually be
released as NetBSD 1.5.3. I've successfully run a 1.5.3_ALPHA kernel
on a 1.5.2 userland (and then updated some stuff like fsck_ffs, newfs,
dumpfs, dump, and other ffs related tools) with minimal impact.
You can access that code in AnonCVS as the "netbsd-1-5" branch tag, or
under
ftp://ftp.netbsd.org/pub/NetBSD/NetBSD-release-1-5/
If possible, try and format the partition with a lot less cylinder
groups, by trying larger values for the "-c" option on newfs (e.g.,
"-c 256"). If you intend to store large files, you could increase the
number of bytes per inode from 4K to something like 16K or 32K with
"-i 16384". For a file system that large it might also help to
increase the block & fragment size from 8K/1K to 16K/2K with
"-b 16384 -f 2048". Finally, if you are considering upgrading to a
1.5.3_ALPHA or -current kernel, wait until after then before
reformatting your partition, and use an up-to-date newfs to do it.
Luke.