HP 3PAR virtual copy provides Point-In-Time thin-aware copy of base volume.
As part of the virtual copy process, HP 3PAR software uses allocate-on-write (or redirect-on-write) method which freezes the base volume and write all new data on other disk (virtual copy disk).
You can create Virtual copies of fully provisioned VV, Thin Provisioned VV or of virtual copy itself.
There are multiple use cases for the virtual copy, for example, integration with enterprise level backup technologies, application recovery etc… Backup software vendors like Veeam, Symantec, HP, Commvault developed backup software’s by integrating HP storeServe virtual copy/ snapshot technology.
3PAR virtual copy feature is provided through “HP 3PAR Virtual Copy Software” license and it can take up to 500 PIT copies of base volume without impacting applications, up to 256 of which can be read-write copies.
Step by step instructions to create 3PAR virtual volume:
· Make sure that your 3PAR system is licensed for Virtual Copy feature (HP 3PAR License check)
· In HP 3PAR console and navigate to Provisioning and select Virtual Volumes in left pane.
· In the right pane, you see all virtual volumes created on 3PAR array
· Select the virtual volume for which you need virtual copy and select "Create Virtual Volume"
Check parent volume and select destination volume naming convention. There are 3 types of naming convention available, so select whatever make sense to your organisation and the way you plan your snapshots.
· Volume name followed by time stamp (@vvname@.@y@@m@@d@@H@@M@@s@)
· Volume name followed by current count of VVs created (@@vvname@.@yCount@)
· Volume name followed by count in seconds since the epoch (@vvname@.@s@)
· User defined
In this example, I have selected default option i.e. Volume name followed by time stamp (@vvname@.@y@@m@@d@@H@@M@@s@)
Then select whether it’s Read only or Read/Write copy. Default option is Read/Write.
HP’s explanation on Read/Write copy is “Read/ Write: Select access permissions for the snapshot. To prevent modification of this snapshot, select Read Only. To allow modifications to tis snapshot or to use it to restore data on a different host, select read/ write
Note that snapshots must alternate permissions, so if the snapshot has the same access permissions as the parent volume, the system creates two snapshot (e.g. RO>RW >RO)”
Then select show advanced options if you want to configure retention and expiration times. Be careful with retention time as system won’t allow you to delete virtual copy until retention time finishes.
Generally we use expiration time, a week or a month or a year.
Select “Create Schedule” in above screenshot if you want to schedule creating virtual copies to a particular base volume.