Use 36.4 or 18.2-7133 Performance

[vb8304]

We are currently putting together a new RS/6000 server and we have a choice of whether to use 1 7133 ssa array with 36.4 drives or 2 7133 disk arrays with 18.2 drives. Any suggestions? These will contain multiple progress databases and use RAID 0+1 or RAID 10.

Thanks.
Vince.

 

[IgorFranco]

Depends on two points:

1- Two 7133 towers are much more expensive than 1 tower
2- The performance obtained spreading data between more discs is better then the opposite. I suggest you to buy 10k ou 15k rpm discs. The seektime and latency is better with this discs and with this kind of configuration.

Why don't u use RAID-5 ? Performance ?
Well, RAID-5 is not that bad. The write performance is worst, but is acceptable. Using an SSA RAID adapter (6225 and 6230) with FAST WRITE CACHE you can get a much better performance.
See

http://www.storage.ibm.com/hardsoft/products/ssa/rs6k/6225_6230.html.

Best Regards
Igor
Brazil

 

[vb8304]

Thanks for the link. It was helpful. I will have to check into what type of SSA adapters we are getting. It seems that the willingness to loose half of your disk space to RAID 0+1 is also another factor. RAID 5 wins in this category but I suppose, if disk space is not an issue, RAID 0+1 still offers the best in terms of Write performance.

Again thanks.
Vince.