Last week whilst trying to get to grips with SQL Server AlwaysOn Failover Clusters, I set up a simple iSCSI target using the “iscsitarget” package as per the Debian docs. However when trying to validate the cluster in WSFC (Windows Server Failover Clustering) the disk checks failed with:

“does not have the inquiry data (SCSI page 83h VPD descriptor) that is required by failover clustering”

This has something to do with the scsiId, which is required by the cluster manager to control volume ownership, being supplied by iscsitarget in a format unsupported by WSFC.

I failed to find a workaround for this and instead switched to using “tgt” to serve the iSCSI targets. I was pushed for time, and couldn’t find a straightforward guide so I’m documenting my steps here.

1) Install tgt:

# apt-get install tgt

2) Enable and start tgt:

# systemctl enable tgt.service
# systemctl start tgt.service

3) Create the iSCSI target(s) and add their backing stores:

# tgtadm --lld iscsi --op new --mode target --tid 1 --targetname iqn.2001-04.com.example:storage.lun1
# tgtadm --lld iscsi --op new --mode logicalunit --tid 1 --lun 1 --backing-store /dev/sdb1

4) Bind the target to listen on all interfaces, with a user account:

# tgtadm --lld iscsi --op bind --mode target --tid 1 -I ALL
# tgtadm --lld iscsi --op new --mode account --user mssql --password secret
# tgtadm --lld iscsi --op bind --mode account --tid 1 --user mssql

5) Dump the config out into a configuration file:

# tgt-admin --dump > /etc/tgt/conf.d/default.conf
# sed -i -e 's/PLEASE_CORRECT_THE_PASSWORD/secret/' /etc/tgt/conf.d/default.conf

6) Restart to ensure the configuration is picked up.

# systemctl restart tgt.service