--- Deen Dayal <deen.dayal@xxxxxxxxxxxxxxx> wrote: > We are planning to move our current database to new > Hardware Sun 12k + > Hitachi SE 9970. > > Our current database runs on Sun A5000 array with > Raid0+1 on raw devices. > Sun engineer who is here at our site for > implementation of Hitachi SE9970 > suggests that we should go Raid5 ( 3 + 1P ) in the > parity group as RAID5 > gives better read performance than raid0+1 and any > writes are going to the > cache any way, so we should not be worried about > write performance. There is > 16GB cache on the Hitachi. That salesperson made their quota right there. Their golf pro should be sending you a fruit/cheese basket. > Database is going to be striped across 10 parity > groups and each parity group consists of 4 physical > disks. no wonder my !@#$%^ nj taxes are so damned high. 4 drive raid 5 volume? ask him to do the math. ask him what you optimal db_file_multiblock_read_count should be. if he would have said 5 drive RAID 5 volume, I would have at least listened further. does he have the slightest clue as to _your_ application's block size (e.g. db_block_size). the SA was assimilated. hopefully, the vendor took him out on a most enjoyable venture to a city such as Montreal. One full of culture. beware of a small, slimy creature with large teeth tearing open his abdominal wall (from the inside) to escape to gestate into an 8 foot tall, mean, human chewing alien. As with database re-orgs, new hard drives that are say Ultra 320 SCSI (320 MB/sec interface), replacing existing U2W SCSI (80 MB/sec interface) - where the new, sexier models outperform the older, more reliable but closer to MTTF, 4 year old models, masks the true issue. At least you aren't comparing apples. baarf. Pd check out the paper at hotsos.com on "aligning database block and stripe size boundaries". ---------------------------------------------------------------- Please see the official ORACLE-L FAQ: http://www.orafaq.com ---------------------------------------------------------------- To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx put 'unsubscribe' in the subject line. -- Archives are at //www.freelists.org/archives/oracle-l/ FAQ is at //www.freelists.org/help/fom-serve/cache/1.html -----------------------------------------------------------------