StorEdge 9990 4+4 versus 7+1 LDEVs
Greetings,
At a planning meeting the other day, one of Suns storage gurus completely dismissed using 7+1 LDEV's and suggested 4+4 because we have an extreme requirement for reading (returning queries in a hurry from mind boggling record numbers) and some writing to a very large Oracle database. This was a bit of a surprise to me but after doing some research, I am starting to agree with him.Perhaps I have been mislead over the years with software mirroring versus hardware mirroring.
The database is so large, it is almost impossible to backup on a daily basis (with current infrastructure) which is even more of an incentive to use the 4+4 LDEVs. We have to rely on the hardware and replication to cope for major problems. Each Veritas 250 GB volume on the host uses 16 spindles in the 9990 which is partitioned into four areas.
Does anyone have an obversed opinion on performance of 4+4 versus 7+1. I have also heard the 6+2 has performance overheads and I would be interested in hearing from anyone that has implemented it. Our NetApps systems use 6+2 but as they are only NFS filers, the performance cant be expected to be spectacular.
Thanks for your time.
Stephen
