On Thu, 1 Apr 1999, Val Bercovici (NetApp) wrote:
My simple rule is minra=on for crazy apps like INN what have tons of small totally random I/O's and minra=off for almost anything else. Basically, if you think caching will help you in any way you want minra off.
Ah, okay, so the crossover point is much closer to the "millions of tiny files" end of the spectrum. We have a bunch of F230's with "split" mailbox spools (about 3.5 million inodes) which are still probably better off with minra=on, although another pair with traditional monolithic mailboxes ought to have minra turned off then.
Actually, the 9GB SCSI drives I believe you're using are only rated for a max (not sustained) external transfer rate of 5MB/sec, so the numbers you're seeing really make sense to me.
Only 5MB/sec? That doesn't sound right to me, especially for a 7200-rpm FC-AL drive (the ST19171FC's). The narrow SCSI Quantum in my workstation gets 8.1MB/sec on sequential block reads averaged across the entire drive.