HP 3PAR X9000 File Serving Software (IBRIX) Implementation Guide (QL226-96987, June 2013)

The preceding figures show that the RAID level of a TPVV has changed from RAID level 1 to RAID
level 5.
To use the dynamic optimization feature to change the RAID level of a virtual volume, using the
HP 3PAR OS CLI, follow these steps:
1. Create multiple virtual volumes of different RAID level using either the HP 3PAR OS CLI or the
HP 3PAR Management Console.
2. Export these virtual volumes to the StoreAll 9300 host and create a mounted file system using
the StoreAll OS GUI or CLI.
3. Begin I/O on the mounted file system.
4. If you have purchased the HP 3PAR Dynamic Optimization license, you can change the volume
parameters and update the layout of the volumes, online (that is, without disrupting the I/O
on the file system). In this case, we are changing the RAID level of a virtual volume. You need
to change the CPG of the virtual volume to the CPG of a different RAID level.
For example, to change the RAID level of a FPVV from RAID level 1 to RAID level 5, you must
change the CPG of that FPVV which is at RAID level 5. You can use the following command
to do so:
# tunevv usr_cpg <CPG> [options <arg>] <VV_name>
5. For more options for the tunevv command, see the “3PAR InForm® OS 2.3.1 CLI Reference,
which is available on the BSC website:
http://www.hp.com/go/bsc
For example, to change the RAID level of a virtual volume named vv1 so that it will belong
to the other CPGs at RAID level 5, issue the following command:
# tunevv usr_cpg Raid5_CPG vv1
6. Once the tunevv command is issued, a task begins the conversion. You can view the status
of the task using the following command:
# showtask [options <arg>] [task_name> | <pattern>]
You can verify, in the meantime, that there has been no disruption in the I/O on the file system.
Thus, volume parameters (the RAID level in this example) can be changed on the fly using the
HP 3PAR Dynamic Optimization feature.
Using Persistent Cache Software
HP 3PAR Persistent Cache is a resiliency feature built into the HP 3PAR OS that allows “always
on” application and virtual-server environments to handle unplanned controller failures gracefully.
Persistent Cache eliminates the substantial performance penalties associated with traditional arrays
and the “write-through” mode so that the HP 3PAR StoreServ Storage can maintain required service
levels even in the event of a cache or controller node failure.
Persistent Cache software allows systems to maintain a high level of performance and availability
during node failure conditions, and during hardware and software upgrades. This feature allows
the host to continue to write data and receive acknowledgments from the system if the backup
node is unavailable.
Persistent Cache leverages the clustered architecture with its unique mesh-active design to preserve
write-caching by rapidly re-mirroring cache to the other nodes in the cluster in the event of a failure.
52 Storage Allocation for Access by the HP StoreAll 9300 and HP 3PAR StoreServ Storage Usage