Yes, ide vs scsi benchmarks are usually skewed due to caching.
SCSI disables
drive cache by default whereas IDE enables it by default.
Yes, I disable caching. So I get (really) bad performance.
I see the other thread about some broken MegaRaid i4.
What I can say is taht with 3.8-release, I have no problem to use
bioctl.
# bioctl -i ami0
Volume Status Size Device
ami0 0 Online 249998344192 sd0 RAID1
0 Online 249998344192 0:0.0 noencl <Maxtor
4A250J0 RAMB>
1 Online 249998344192 2:1.0 noencl <Maxtor
4A250J0 RAMB>
ami0 1 Online 249998344192 sd1 RAID1
0 Online 249998344192 3:0.0 noencl <Maxtor
4A250J0 RAMB>
1 Online 249998344192 1:1.0 noencl <Maxtor
4A250J0 RAMB>
ami0 2 Degraded 499996688384 sd2 RAID5
0 Online 249998344192 3:1.0 noencl <Maxtor
4A250J0 RAMB>
1 Rebuild 249998344192 1:0.0 noencl <Maxtor
4A250J0 RAMB>
2 Online 249998344192 2:0.0 noencl <Maxtor
4A250J0 RAMB>
ami0 3 Hot spare 249998344192 0:1.0 noencl <Maxtor
4A250J0 RAMB>
I broke the RAID-5 and it starts rebuilding.
I can setup new Hot-Spare.
But nothing was perfect, I had two crashes. I do not have ps and
trace because I was using "ddb.panic=0" to reboot the prod server
automatically. The crash happens when I was on console, I disable
"ddb.panic=1", but "luckily" I get no other crash. And I can not do
postmortem analysis because /var is to small to keep coredump in /var/
crash. I did not have test current. I do not want to stop this server
too long.
So, here is the partial crash report (the dmesg is in one of my other
mails in this thread). I hope it will be partially useful ;-)
fsync failed: type VDIR, usecount 0, writecount 0, holdcount 1, flags
(VBIOONFREELIST|VBIOONSYNCLIST)
tag VT_UFS, ino 6987542, on dev 0, 9 flags 0x0, effnlink 2,
nlink 2
mode 040755, owner 1000, group 1000, size 512 not locked
mounted on: /mnt
panic: sched_sync: fsync failed
Starting stack trace...
panic(d057fa84,d7c73960,ea077f5c,d7c73960,d7c73960) at panic+0x71
panic(d04f9970,d1b8b29c,d7d078f8,d17b4620,4) at panic+0x71
sched_sync(d7d078f8) at sched_sync+0x17a
Bad frame pointer: 0xd06f1ed8
End of stack trace.
syncing disks... 250 250 248 244 230 212 199 181 164 150 135 124 112
108 102 89 69 45 23 1 giving up
rebooting...
fsync failed: type VDIR, usecount 0, writecount 0, holdcount 1, flags
(VBIOONFREELIST|VBIOONSYNCLIST)
tag VT_UFS, ino 7011086, on dev 0, 9 flags 0x0, effnlink 2,
nlink 2
mode 040755, owner 1000, group 1000, size 512 not locked
mounted on: /mnt
panic: sched_sync: fsync failed
Starting stack trace...
panic(d057fa84,d7c53e60,ea077f5c,d7c53e60,d7c53e60) at panic+0x71
panic(d04f9970,d18eda9c,d7d078f8,d17b467c,4) at panic+0x71
sched_sync(d7d078f8) at sched_sync+0x17a
Bad frame pointer: 0xd06f1ed8
End of stack trace.
syncing disks... 320 320 318 318 318 318 318 318 314 311 303 293 285
280 269 254 240 233 230 221 giving up
sd2: WARNING: cache synchronization failed
rebooting...
Cordialement,
Jean-Girard Pailloncy
