On 2016-10-06 11:34, Kenneth Westerback wrote:
1) Why do you say >8 but only give an example using 10 disks?
2) fdisk and disklabels for all the disks you test would be useful, as
would the verbatum output from newfs.
3) The size of the disks would also be useful (although the information
above would contain this).
4) To eliminate the size of the resulting volume being a problem and
possibly eliminating ffs2 vs ffs issues trying to create a volume with
smaller chunks (say 100MB) on each disk would be another useful data
point.
.... Ken
1. That was a bit of an assumption on my part, just tested 9 disks and
it works fine. My raid arrays have even disk spacing, so using odd
numbered arrays is not ideal so i never tested it before hand. I can
verify that 10 disk arrays, 11 disk arrays, and 12 disk arrays are
broken in the same manner however.
2. To make testing a bit easier i decided to start doing debugging on my
Sun T5120 at home. I only have 2 disks, but have setup 10 ~100MB
partitions on sd0.
# disklabel sd0
# /dev/rsd0c:
type: SCSI
disk: SCSI disk
label: ST914602SSUN146G
duid: 82bafda60ea79f65
flags: vendor
bytes/sector: 512
sectors/track: 848
tracks/cylinder: 24
sectors/cylinder: 20352
cylinders: 14089
total sectors: 286739329
boundstart: 0
boundend: 286739329
drivedata: 0
16 partitions:
# size offset fstype [fsize bsize cpg]
a: 223872 0 RAID
b: 223872 223872 RAID
c: 286739329 0 unused
d: 223872 447744 RAID
e: 223872 671616 RAID
f: 223872 895488 RAID
g: 223872 1119360 RAID
h: 223872 1343232 RAID
i: 223872 1567104 RAID
j: 223872 1790976 RAID
k: 223872 2014848 RAID
#dd
After that i setup raid 5 between all of these partitions...
# bioctl -c 5 -l sd0a,sd0b,sd0d,sd0e,sd0f,sd0g,sd0h,sd0i,sd0j,sd0k
softraid0
sd2 at scsibus2 targ 1 lun 0: <OPENBSD, SR RAID 5, 006> SCSI2 0/direct
fixed
sd2: 981MB, 512 bytes/sector, 2009088 sectors
softraid0: RAID 5 volume attached as sd2
#
Then add a disklabel to sd2 and format it...
# disklabel sd2
# /dev/rsd2c:
type: SCSI
disk: SCSI disk
label: SR RAID 5
duid: 9388bbda6be53605
flags: vendor
bytes/sector: 512
sectors/track: 63
tracks/cylinder: 255
sectors/cylinder: 16065
cylinders: 125
total sectors: 2009088
boundstart: 0
boundend: 2009088
drivedata: 0
16 partitions:
# size offset fstype [fsize bsize cpg]
a: 2008125 0 4.2BSD 2048 16384 1
c: 2009088 0 unused
#
# newfs sd2a
/dev/rsd2a: 980.5MB in 2008124 sectors of 512 bytes
5 cylinder groups of 202.47MB, 12958 blocks, 25984 inodes each
super-block backups (for fsck -b #) at:
32, 414688, 829344, 1244000, 1658656,
#
And now we mount it and try to write data to it...
# mount /dev/sd2a /mnt
# cd /mnt
# dd if=/dev/zero of=test bs=1m count=128
dd: test: Input/output error
1+0 records in
0+0 records out
0 bytes transferred in 0.112 secs (0 bytes/sec)
#
I plan on building a debug kernel tonight see if i can get anything out
more out of it.
