One of the questions that our team frequently encounters is regarding the type of scsi reservation Solaris Cluster uses. This can be determined in a very simple way. How many nodes does a shared disk connected to?
If the shared disk is connected to 2 nodes, then it uses SCSI-2 reservations. If it is connected to more than 2 it uses SCSI-3 reservations. Where can you find more details regarding this? You should be checking out the scdidadm man page.
bash-3.00# man -M /usr/cluster/man scdidadm
Reformatting page. Please Wait... done
System Administration Commands scdidadm(1M)
NAME
scdidadm - device identifier configuration and administra-
tion utility wrapper
SYNOPSIS
/usr/cluster/bin/scdidadm -C
/usr/cluster/bin/scdidadm -c
/usr/cluster/bin/scdidadm -F {pathcount | scsi3 | useglobal} instance
/usr/cluster/bin/scdidadm -G
/usr/cluster/bin/scdidadm -G {pathcount | prefer3}
/usr/cluster/bin/scdidadm {-l | -L} [-h] [-o fmt]... [path | instance]
/usr/cluster/bin/scdidadm -R {path | instance | all}
/usr/cluster/bin/scdidadm -r
/usr/cluster/bin/scdidadm -T remote-nodename -e replication-type
/usr/cluster/bin/scdidadm -t source-instance:destination-instance -e replication-type
[-g replication-device-group]
/usr/cluster/bin/scdidadm [-u] [-i]
/usr/cluster/bin/scdidadm -v
.
.
pathcount Determines the fencing protocol by
the number of DID paths that are
attached to the shared device.
o For a device that uses
fewer than three DID paths,
the command sets the SCSI-2
protocol.
o For a device that uses
three or more DID paths,
the command sets the SCSI-3
protocol.
scsi3 Sets the SCSI-3 protocol. If the
device does not support the SCSI-3
protocol, the fencing protocol set-
ting remains unchanged.
To find out the method being used, you can execute the following command:
bash-3.00# scdidadm -G
The cluster is currently configured to use DID path count algorithm to determine fencing protocol for shared devices.
To find the reservations keys on a disk, you should use the scsi command:
For SCSI-2, a sample output from a 2 node cluster:
bash-3.00# /usr/cluster/lib/sc/pgre -c pgre_inkeys -d /dev/did/rdsk/d3
key[0]=0x47cd37ab00000001.
key[1]=0x47cd37ab00000002.
For SCSI-3, a sample output from a 4 node cluster:
bash-3.00# /usr/cluster/lib/sc/scsi -c inkeys -d /dev/did/rdsk/d10s2
Reservation keys(4):
0x47f5da4400000003
0x47f5da4400000001
0x47f5da4400000002
0x47f5da4400000004
WARNING: Do not administer any of these commands without understanding the implications - do it only on a test cluster lest you're willing to land in trouble!!