Revitialising old MSA hardware

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Published: Thursday, 01 August 2013 15:58

Recently a whole bunch of old HP Modular Smart Array (MSA) 2000 Gen1 systems with expansion enclosures returned from a storage on demand project.

The MSA2000 isn't a really fast system, the inbuilt RAID controllers are quite slow compared to todays entry level storage systems like the HP P2000 or FTS Eternus DX80/90 systems so reuse them in other projects simply doesn't make any sense.

A colleague asked for some JBODs to be used with Microsoft Server 2012 and their Storage Spaces. Until now I knew very few about Windows Storage Spaces. He told me about the concept of Storage Spaces and the use of really dumb JBODs behind SAS HBAs without any RAID functionality.

Knowing this concept from storage virtualization products like Nexenta or any other ZFS based storage systems this attracts my attention. Using software RAID with JBODs instead of HW RAID controllers can really speed up the storage. Why? HW RAID controllers are built on special ASICs that do RAID calculations. The max speed is determined by the power the ASIC delivers.

Even if the ASIC is special built for these RAID operations a new generation Intel or AMD CPU will deliver a far better performance than these ASICs can. Furthermore, these standard CPUs are that powerful, they do RAID calculations by the way. 

So using JBODs with software RAID or concepts like Storage Spaces definetly makes sense.

Back to the topic..... using MSAs for Storage Spaces isn't what we want. They are not "dumb enough". So I tried to go a different way. The expansion encloures from the MSA are simple JBOD devices with SAS interface. Why not simply attach them to a standard SAS HBA?

HP (and probably all other storage vendors too) normally isn't interested in supporting this kind of setup. Furthermore, they normally try to prevent such setups by using special firmware versions on the JBODs I/O module and the hard disks so they only work behind a MSA or whatever they are designed for.

I found a SC44Ge 3Gb SAS HBA (relabeled LSI controller without RAID functionality) and connected the HBA with one of the expansion enclosure.

Surprise: this setup worked. The LSI controller discovered all 12 450GB SAS drives.

With this setup I'm now able to built my high-performance NAS system while using quite old but still fast SAS drives, a low-cost SAS HBA and a standard server with adequate CPU power.

Even if this setup is not officially supported by HP it works and once more the bottom line is: not mentioned doesn't mean it doesn't work.