Hewlett Packard Enterprise HPE XP7, User Manual, Page: 63 / 311

• Fast Snap pairs that share P-VOLs or are in higher and lower layers of a snapshot tree cannot be
defined in the same consistency group. If they are defined in the same consistency group, the
raidcom add snapshot
command is rejected.
• Do not place pairs that are not in consistency groups, in a group defined by the RAID Manager
configuration definition file. If these pairs are in the same group, the
pairsplit
command may
terminate and the snapshot data may not be the P-VOL data generated when a storage system
received the
pairsplit
command.
• Only one consistency group can be specified for a group defined in the RAID Manager configuration
definition file.
• When a pair for which a consistency group is specified and is already created, if you specify another
consistency group to create a pair, the pair is added to the same consistency group.
• To specify multiple consistency groups, use the RAID Manager configuration definition file to define the
same number of groups as the consistency groups you want to specify.
Fast Snap snapshot group requirements
Item Requirement
Name Character limit: 32.
You can change snapshot group names using RAID Manager
commands. For details about RAID Manager commands, see
Appendix A and the HPE XP Storage RAID Manager Installation
and Configuration User Guide .
Group and FS pair limit
• Snapshot groups per storage system: 2,048.
• FS pairs per snapshot group: 8,192.
Pair type Snapshot and cloned pairs cannot be contained in a single snapshot
group.
Restrictions for Snapshot groups:
• When creating a Fast Snap cascaded pair with the CTG mode specified using RAID Manager, a
volume belonging to the snapshot group and the following volumes cannot be contained in the same
snapshot group:
◦ The P-VOL or S-VOL of a volume belonging to the snapshot group
◦ A volume that uses the same P-VOL with a different MU number as the volume belonging to the
snapshot group
Fast Snap planning requirements
When you create Fast Snap pairs for a P-VOL for the first time, the number of pairs that you can create in
a storage system depends on several variables.
Fast Snap snapshot group requirements 63