Well, it's not really NetBSD-current (system runs 1.3.2) related, sorry
for that.

PREAMBLE:

Last saturday night/sunday morning I upgraded our web proxy from
Squid.1.NOVM.22 to Squid.2.0.RELEASE1. Since 2.0 uses a different cache
structure as 1.x I had to clear the disk cache. I've decided to newfs
the cache partition (~3GB) instead of deleting thousands of files.

PROBLEM:

As the cache started to fill up this week I noticed
"Oct  8 16:57:32 Server /netbsd: /usr/local/squid/cache: optimization
changed from TIME to SPACE" in /var/log/messages.

`df` said that the partition was around 33% full
`fsck -n` nothing special and
`tunefs -N` that everything was alright (except optimization)

Even more strange, as the cache filled up to around 36% I got:
Oct  9 10:46:41 Server /netbsd: /usr/local/squid/cache: optimization
changed from SPACE to TIME

So, my questions are:
* What may cause this optimization switching? (I noticed it before - but
  with ~95% full cache, so I thought it was normal)
* Have I've done something wrong?
* Is it a worth a PR?
* Is it potentially dangerous?

TIA,
  Thilo Manske.


APPENDIX:

The system is an i386 (if it matters) and the partition is on an IBM UW
connected to an Adaptec 2940UW. Uptime now around 64 days.

Kernel is NetBSD1.3.2 with these (maybe) related options:
options QUOTA           # UFS quotas
options NFSSERVER       # Network File System server
options FIFO            # FIFOs; RECOMMENDED
options NMBCLUSTERS=3D1024
options KMEMCLUSTERS=3D2048
options MAXVNODES=3D8000
options AHC_TAGENABLE                   # tagged Command queueing
options AHC_SCBPAGING_ENABLE            # SCB-paging
(If anybody wants to see it i can mail/post the complete config file)

Output from tunefs now:
tunefs: current settings
        maximum contiguous block count 8
        rotational delay between contiguous blocks 0ms
        maximum blocks per file in a cylinder group 2048
        minimum percentage of free space 5%
        optimization preference: time
        track skew 0 sectors

The partition is mounted with
/dev/sd0g       /usr/local/squid/cache  ffs     rw,noatime 0 4
in /etc/fstab

The label of the disk looks like:
# /dev/rsd0d:
type: SCSI
disk: ibmdchs
label: dchs04u
flags:
bytes/sector: 512
sectors/track: 162
tracks/cylinder: 9
sectors/cylinder: 1458
cylinders: 6077
total sectors: 8860266
rpm: 3600
interleave: 1
trackskew: 0
cylinderskew: 0
headswitch: 0           # milliseconds
track-to-track seek: 0  # milliseconds
drivedata: 0

7 partitions:
#        size   offset    fstype   [fsize bsize   cpg]
  a:    34992        0      4.2BSD     1024  8192    16   # (Cyl.    0 - =
23)
  b:   368874    34992        swap                        # (Cyl.   24 - =
276)
  c:  8860266        0      unused        0     0         # (Cyl.    0 - =
6076)
  d:  8860266        0      unused        0     0         # (Cyl.    0 - =
6076)
  e:    43740   403866      4.2BSD     1024  8192    16   # (Cyl.  277 - =
306)
  f:  1650456   447606      4.2BSD     1024  8192    16   # (Cyl.  307 - =
1438)
  g:  6762204  2098062      4.2BSD     1024  8192    16   # (Cyl. 1439 - =
6076)

(In-core and on-disk labels are identical, I've checked it.)
--=20
Mir ist mein Signature entlaufen :-(. Wer es findet, sende es bitte an
Thilo.Manske@HEH.Uni-Oldenburg.DE zur=FCck. Danke!=20