Virtual TapeServer 6.03.41 Installation Guide

94 | Configuring and Maintaining GFS for Virtual TapeServer
2. Confirm the Fibre Channel port is available and confirm that the Linux operating system
sees the LUN defined for the file system by the storage array. This command will list all
SCSI devices.
sg_map -x
The output for this command is similar to the following:
/dev/sg0 1 0 4 0 1 /dev/st0
/dev/sg1 1 0 5 0 1 /dev/st1
/dev/sg2 1 0 6 0 8
/dev/sg3 4 0 0 0 0 /dev/sda
/dev/sg4 4 0 0 1 0 /dev/sdb
/dev/sg5 4 0 0 2 0 /dev/sdc
/dev/sg6 4 0 0 3 0 /dev/sdd
/dev/sg7 4 0 0 4 0 /dev/sde
Note st devices are tape drives and sd devices are disks. Verify all disks defined in the
/etc/fstab are listed.
3. If the No sg devices found message is displayed or partitions are missing, direct the
operating system to rescan for the devices on the Fibre Channel bus(es) from the console
or using a Telnet command prompt. Enter the following commands:
cd /usr/local/tape/bin/
./hp_rescan -a
Example output for the last command:
Rescanning /proc/scsi/qla2300/4...
Rescanning /proc/scsi/qla2300/5...
Removing /proc/scsi/qla2300/4, target 0, LUN 32
Scanning /proc/scsi/qla2300/4, target 0, LUN 32
scsi4 00 00 02 JetStor Volume R001 Direct-Access
scsi4 00 00 00 JetStor Volume R001 Direct-Access
scsi4 00 00 01 JetStor Volume R001 Direct-Access
scsi4 00 00 03 JetStor Volume R001 Direct-Access
scsi4 00 00 04 JetStor Volume R001 Direct-Access
4. Start GFS services after you confirm that all the devices defined in /etc/fstab are
available. Follow the procedure in
Starting GFS on page 92.
Fencing is a term used to describe when a server is excluded from the GFS cluster. When a
server is not available for updates and cannot vote in the GFS process, it may be fenced off
from access to the file system. You must rejoin that server to the cluster. To verify if fencing is
occurring, complete these steps:
1. Check the /var/log/messages file on the primary VTS server. A message may be listed
that says VTS was unauthorized to join cluster and fence failed.
2. Restart the GFS cluster by bringing GFS down and back up. See Starting GFS on page 92.