HP StorageWorks Scalable File Share User Manual

Page 281

Troubleshooting failed SFS20 arrays

9–57

Identify the LUNs that the MDS or OST service is based on, by using the

show filesystem

filesystem_name

command as follows:

sfs> show filesystem data
.

MDS Information:

Name LUN Array Controller Files Used Service State Running on
----- --- ----- ---------- -------- ---- ------------- ----------
mds8 41 - 2.3M 20% running south2

OST Information:

Name LUN Array Controller Size(GB) Used Service State Running on
----- --- ----- ---------- -------- ---- ------------- ----------
.

ost29 34 3 scsi-1/1 290 30% running south4
.

In this example, the

mds8

service is using the mirrored LUN number 41.

Identify the component LUNs that are used to mirror the LUN, using the

show lun lun_number

command as shown in the following example:

sfs> show lun 41

LUN (WWID): raid_41
LUN (Number): 41
.

Component LUN Size (GB)
------------- ---------
19 1900
22 1900

In this example, LUNs 19 and 22 are components of LUN 41.

As displayed by the

show filesystem

command in Step 2, the

mds8

service is running on the

south2

server. Log in to that server and determine which RAID device is associated with LUN 41, as

shown in the following example:

# ls -l /dev/hpls/dev41a

lrwxrwxrwx 1 root root 15 Nov 4 17:23 /dev/hpls/dev41a -> /dev/md0

You can confirm this by examining the

raidtab

file used to create the RAID device, as shown in the

following example:

# cat /var/raid/raidtab.mds8
DEVICE /dev/hpls/dev19a
DEVICE /dev/hpls/dev22a
ARRAY /dev/md0
level=raid1
num-devices=2
devices=/dev/hpls/dev19a,/dev/hpls/dev22a
# chunk=8 # For use by lsraidlib.tcl

Use the

mdadm

command and the

/proc/mdstat

file to examine the status of the component

device, as shown in the following example:

# mdadm --detail /dev/md0
/dev/md0:
.

State : clean, degraded
.