May 23, 2005
Storage Information
With Bill's post about storage to his blog, I thought it might be a good time to describe WOU's current storage enviornment as well as our new SAN ( Storage Area Network ) and some of the main differences.
Our current storage enviornment is built from individual array's called 3510's Information on them can be found on Sun's website. Each of these array's have 12 disks that are built into a Raid 5 group with a global spare. Raid 5 is really the sweet spot with regard to performance and reliability. If you're interested in the nuts and bolts of Raid 5 you can read up on it here.
Our new SAN is the Hitachi 9980. With this type of SAN we have a bunch of disks ( yes this is the technical term ) configured in Raid 5 groups. The number of global spares in the 9980 is dependent upon the number of total disks. Currently we have 3 global spares.
Some basic differences:
1. Hitachi is enterprise level storage, while the 3510's are entry level storage.
2. Hitachi storage is engineered to provide 99.999% reliability, 3510's 99.9%.
3. Adding storage to the Hitachi's can be done by purchasing disks and adding them to the current layout, the 3510's are purchased fully populated and non-upgradeable.
4. The Hitachi system has some predictive self healing built into the box, and will call out to notify of any issues it may be having, the 3510 does not do any of this.
5. Not only is it possible to add disks to the Hitachi system, but we can also add controllers ( how the servers talk to the storage ) and cache ( very fast memory the more the better ). The ability to "Add-On" is called scaling. The Hitachi system scales very well, while scaling with the 3510's is done by adding more array's.
All that being said, over the past year we have had 100% uptime with the 3510's and performance has been very acceptable. We expect the Hitachi system be as reliable, and our current performance testing has exceeded any expectation.
Posted by knabet at May 23, 2005 08:32 AM