Re: performance of internal vs san for 7TB

Diego Kesselman
<diegokesselman@xxxxxxxxx> wrote
on Wed, 03 Jun 2015 21:51:27 GMT:

According to IBM you MUST use a dedicated pool for production
IBM i and they recommend on using at least the same amount of
vDisks than internal , desirable 80 GB LUNs , and at least the
same amount of physical disks. Cache has big inpact on
performance. Use always 15 k disks.

When using SAN attached storage, there are no MUST or ALWAYS
rules. There are guidelines which fall into the HIGHLY
RECOMMENDED or BEST PRACTICES arenas.

I have several customers who are doing almost everything against
the best practices and performance meets every business
requirement. In all cases, an informed decision to go against
guidelines was made by using Disk Magic to model and
understanding where performance bottlenecks might be introduced.