On Friday August 26, strombrg@xxxxxxxxxxxxxxx wrote: > > I've been working on a RAID setup with dual RAID controllers and > three expansion boxes - 48 disks in all, including data, parity and > global spares. If there are 48 drives, why do your drive-numbers go up to 59? Confusing but not important. Presumably these are 360G drives (or there abouts) and you are hoping to use about 42 for data and the remaining 6 for redundancy. I feel this a bit tight but could be workable. If you were using Linux-soft-raid, I would probably suggest 3 16-drive raid6 arrays, possibly making 1 a 15 drive raid6 so there is one global spare. However I gather you are using hardware RAID - do the controllers support RAID6 ?? > > Please be sure to use a fixed-pitch font when viewing the tables found > below. BTW, if people weren't so terrified of HTML, I could just make a > nice HTML table for easy reading without silly font requirements... You mean some mail readers use variable-width-fonts to display text/plain? How broken! > > > Does anyone have any comments on: > > 1) The sanity of these 10 disk RAID 5's? It depends on the drives. If you are using you-only-get-what-you-pay-for-IDE-drives, then I would say it is insane. If you are using you-pay-for-the-quality SCSI drives, then you should be fairly safe. > > 2) The degree of loss of reliability incurred by moving 3 disks from > global spare to data? That depends a bit on your warranty arrangements on the drives. If it's next-day-replacement (Really, truly) then it is probably OK. If it is 'send us the bad drive and we'll see what we can do', then I would suggest thinking again. > > 3) The degree of loss of reliability incurred by moving 2 disks from > global spare to data? > Should be safe enough. However I don't understand why you have 4 9+1 arrays, and 1 X+1 for varying X. Maybe 9+1 is the largest the controller will give you, so you have to go to 5 arrays. In that case, 4 8+1 arrays, 1 9+1 array, and 2 global spares would seem a more sensible arrangement. NeilBrown - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
