Re: SPARC64: input/output error on softraid 5 with more than 8 disks

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.