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Conference spezko::cluster

Title:	+ OpenVMS Clusters - The best clusters in the world! +
Notice:	This conference is COMPANY CONFIDENTIAL. See #1.3
Moderator:	PROXY::MOORE

Created:	Fri Aug 26 1988
Last Modified:	Fri Jun 06 1997
Last Successful Update:	Fri Jun 06 1997
Number of topics:	5320
Total number of notes:	23384

5251.0. "Quorum disk failure on SCSI cluster" by CSC32::STUBAI::T_FISHEL () Wed Mar 12 1997 15:30

Hello,

	Quick question: If the quorum disk fails within a two node SCSI 
	cluster with the quorum disk on the shared bus, can the disk be
	hot swapped.  As long as quorum is maintained in the cluster.

	I believe that the disk will mount verify or no longer serve the LBNs.
	After the old disk is replaced and mounted in the cluster, CSP will
	see no QUORUM.DAT, create one. Or the customer can then restore any
	backup to the disk, which will have an old QUORUM.DAT and the CSP
	will update the file data.

	Am I close or way off.

				Tim

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5251.1 Several Levels To This Question... XDELTA::HOFFMAN Steve, OpenVMS Engineering Thu Mar 13 1997 09:42 22

T.R	Title	User	Personal Name	Date	Lines
5251.1	Several Levels To This Question...	XDELTA::HOFFMAN	Steve, OpenVMS Engineering	`Thu Mar 13 1997 09:42`	22
	: Quick question: If the quorum disk fails within a two node SCSI : cluster with the quorum disk on the shared bus, can the disk be : hot swapped. As long as quorum is maintained in the cluster. You'll need to "quiesce" the SCSI bus before disconnecting any SCSI cabling -- see the description on how to hot-swap SCSI disks in the OpenVMS VMScluster documentation. If concerned about this level of failure, I'd recommend that the customer acquire and configure a quorum VAX or Alpha system... If the customer is worried about this level of disk failure but does not want a "quorum host", I'd keep the quorum disk away from any user data. (I'll assume the system disk is shadowed, hence the quorum disk is elsewhere.) If restoring a BACKUP, I'd definitely not restore a disk with a quorum file over the top of a disk with a running quorum file -- image restorations need the disk to be MOUNT/FOREIGN, and the VMScluster quorum managers prefer to see the quorum disk MOUNTed. Not to mention the confusion that might be caused by QUORUM.DAT contents changing underneath things...

:	Quick question: If the quorum disk fails within a two node SCSI 
:	cluster with the quorum disk on the shared bus, can the disk be
:	hot swapped.  As long as quorum is maintained in the cluster.

   You'll need to "quiesce" the SCSI bus before disconnecting any SCSI
   cabling -- see the description on how to hot-swap SCSI disks in the
   OpenVMS VMScluster documentation.

   If concerned about this level of failure, I'd recommend that the
   customer acquire and configure a quorum VAX or Alpha system...

   If the customer is worried about this level of disk failure but does
   not want a "quorum host", I'd keep the quorum disk away from any user
   data.  (I'll assume the system disk is shadowed, hence the quorum disk
   is elsewhere.)  If restoring a BACKUP, I'd definitely not restore a
   disk with a quorum file over the top of a disk with a running quorum
   file -- image restorations need the disk to be MOUNT/FOREIGN, and the
   VMScluster quorum managers prefer to see the quorum disk MOUNTed.  Not
   to mention the confusion that might be caused by QUORUM.DAT contents
   changing underneath things...