HP XP Continuous Access Software - Manual (Page 168)

Scope of XP Continuous Access Journal functions with NAS Blade
Scope related to XP Continuous Access Journal
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Volume type
You can use only user LUs as XP Continuous Access Journal primary data volumes (P VOLs)
and secondary data volumes (S VOLs) in a NAS Blade system. You cannot use NAS system
LUs (NAS OS LU, Cluster Management LU, and dump LU) as XP Continuous Access Journal
P-VOLs or S-VOLs.
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Platforms that can access XP Continuous Access Journal P-VOLs or S-VOLs
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File systems that can be allocated in XP Continuous Access Journal P-VOLs
You cannot allocate a file system consisting of 129 or more LUs and using Logical Volume
Manager (LVM) on the NAS OS.
You cannot allocate a volume group consisting of 129 or more LUs if it contains a file system
managed by NAS Sync Image and differential-data storage devices.
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Writing data to an S-VOL when a volume pair is split
When splitting an XP Continuous Access Journal volume pair in the NAS Blade system, change
the S-VOL to write-enable. Ensure that you always specify the
-rw option instead of the -r
option when issuing the XP RAID Manager pairsplit command.
To protect data in the split S-VOL from being written to by the client, use the enas_fsmount
command with the -r option in NAS Blade Manager when mounting the file system in the
S-VOL.
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Path settings
If you use a NAS Blade system with XP Continuous Access Journal, you must add paths to
ports on both CL1 and CL2 to connect the primary and secondary sites.
Scope related to XP RAID Manager
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Relationships of failover and failback on XP RAID Manager and NAS Blade system
XP RAID Manager is not subject to failover and failback by the NAS Blade system. Prepare
the same configuration file as the main node in the standby node except for
ip_address in
the HORCM_MON section. If a failure occurs in the NAS package while XP RAID Manager is
operating and failover occurs, start XP RAID Manager in the standby side and continue
operating XP Continuous Access Journal.
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Protect feature
When using XP Continuous Access Journal in the NAS Blade system, you create and
resynchronize pairs using XP RAID Manager while the NAS Blade system does not recognize
the S-VOL. Therefore, you cannot use XP's RAID Manager protection facility because this
facility prohibits operations of volume pairs the system does not recognize.
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Executing XP RAID Manager commands
To execute XP RAID Manager commands using the nasroot account for logging in to a NAS
package using SSH, use the
sudo command as follows:
Table 31 Executing the pairdisplay command in XP RAID Manager using the sudo command
$ sudo pairdisplay -gg VG01
168 XP Continuous Access Journal operations with NAS Blade