The pool based provisioning model will be the prevalent storage model for Clariion going forward.
But what are Clariion Storage Pools?
Clariion Storage Pools
Clariion Storage Pools can be created from any type of Clariion Disk and can incorporate multiple tiers (FLASH,FC,SATA) in the same pool. LUN creation from a pool is a case of providing three basic inputs such as the name of the pool, the host you’re making the LUN available to and the amount of storage capacity the host should see. These LUNs can be expanded or shrunk and come with additional inputs for the use of storage services such as FAST or Compression.
Let's talk about the latest additions to the storage pool model.
As I stated previously a Thin LUN is constructed of 8KB extents allocated in 1GB slices upon demand from a pool by the CBFS Mapping Service. Well a Thick LUN is a construct of the same type except all the storage is reserved up front but only allocated upon demand in 1GB slices distributed throughput the pool to maximize spindle usage.
The choice going forward isn’t one of FLARE LUNs, MetaLUNs or designing HyperGroups but simply of Thick or Thin? For the most part I think it’s going to be Thin as Thin LUNs enable great levels of capacity utilization but you can non-disruptively migrate the data between them so the choice is yours.
Now that we‘ve discussed pools and pool LUNs we can introduce the new storage services for pool LUNs starting with one of the big ticket releases.
Fully Automated Storage Tiering (FAST)
Even with Clariion FAST LUN Migrator (An analysis tool which highlights LUNs which could benefit from being migrated to Flash Drives) being available for a while now manual tiering can be time consuming and it requires someone to sit down, examine what’s going inside the system and then make a decision as to migrate a LUN or not.
In FLARE 30 FAST introduces four new Automated Storage Tiering Policies for sub-LUN tiering.
The four policies are Auto-Tier (The default), which moves hot data up tiers and cold data down. Highest Available Tier which places as much data on the highest available tier as is possible ranking from hot to cold. Lowest Available Tier which places as much data as possible on the lowest available tier ranking from cold to hot and No Data Movement which prevents movement operations entirely regardless of how hot, warm or cold the data is.
Periodically the system examines the I/O statistics, applies weights depending on the tiering policy and calculates how much data needs to be moved up and how much data needs to be moved down. Data relocation being scheduled to occur every day/only on specified days/only during specified hours or manually with the click of a button.
Any non-pool LUNs non-disruptively migrated into a pool are automatically included in relocation calculations the moment the migration has completed. Meaning non-pool LUNs can be migrated into a pool to leverage FAST, their LUNs unbound after the migration and their storage space added to the pool when the disks in the RAID Group no longer have any data on them.
Having examined FAST operating across tiers of devices, placing the data on the correct tier of storage at the proper time lets drive out even more storage efficiency.
When we examine efficiency through optimization we find that LUN migration to Thin LUNs can maximize overall storage utilization by eliminating any stranded storage which might occur on LUNs which have a significant amount of provisioned but unused storage. That’s one storage efficiency technique.
The use of compression is another.
As of FLARE 30 LUNs can be compressed. If the LUNs aren't already pool LUNs they will automatically migrated to a Thin LUN and compressed using the same compression algorithms found in RecoverPoint as the migration occurs. It's as easy as ticking a checkbox in Unisphere.
What happens if you no longer want the LUN to be compressed? You uncheck the checkbox and the LUN decompresses back to it's original size.
And that’s a high level look of the new storage services available in FLARE 30.
Next time: FAST Cache & Unisphere.
You have been reading Storage Services for Clariion Storage Pool LUNs by Storagezilla.