Hi, The man page that I have for fence_scsi(8) lists (among others) the following restrictions in use:
- The fence_scsi fencing agent requires a minimum of three nodes in the cluster to operate. - In addition, fence_scsi cannot be used in conjunction with qdisk. I am puzzled by those restrictions, as I remember an ancient Digital/Compaq TruCluster V1.x that also used SCSI reservations and had no such restrictions. I cannot see a logical linkage between the SCSI registration and node count in the cluster. Each node does its own reservation attempts and registrations. Question 1: ----------- Why a minimum of 3 nodes are required? I cannot also see any linkage between SCSI reservations and use of quorum disk. SCSI reservations are done on a per device (LUN) basis. Obviously, the qdisk should be excluded from this process, I believe. But once this is done there should not be a problem. Question 2: ----------- Why qdisk cannot be used in conjunction with fence_scsi? SCSI reservations are such a powerful mechanism. Apart from use for fencing they could be used to enforce exclusive access to non-clustered filesystems only to a node that started the service using this particular filesystem. Question 3: ----------- Does Linux cluster use SCSI reservations to enforce exclusin access to non-clustered filesystems on shared storage? Thanks and regards, Chris Jankowski -- Linux-cluster mailing list [email protected] https://www.redhat.com/mailman/listinfo/linux-cluster
