Mirroring Efficacy on RAID5 with Cooked Files

(Did that subject line grab you?) The lobotomized managers at my current worksite -- who make all manner of uninformed (I could say ignorant, but I won't) decisions about infrastructure acquisition, configuration and deployment - plan to ship a system which will host an informixserver (which uses cooked files) with a single RAID-5 partition comprised of half a dozen multi-gigabyte devices -- in spite of advice to the contrary by highly (over)paid and experienced consultants. Now, in attempting to find a way to mitigate the damage, the question is: What use is it to mirror the instances' chunks within the same RAID partition? Would this be helpful in any way? We're using IDS 7.31UC-4 on Solaris 2.7/Intel (don't ask).

Red Valsen <red_valsen@yahoo.com> writes: > (Did that subject line grab you?) Nah, pants still on... > The lobotomized managers at my current worksite -- who make all manner > of uninformed (I could say ignorant, but I won't) I believe the correct word is "PHB" > decisions about > infrastructure acquisition, configuration and deployment - plan to ship > a system which will host an informixserver (which uses cooked files) > with a single RAID-5 partition comprised of half a dozen multi-gigabyte > devices -- in spite of advice to the contrary by highly (over)paid and > experienced consultants. You'r one of those consultants? > Now, in attempting to find a way to mitigate the damage, the question > is: What use is it to mirror the instances' chunks within the same RAID > partition? Would this be helpful in any way? > > We're using IDS 7.31UC-4 on Solaris 2.7/Intel (don't ask). On the good side: -When some lUSER deletes one of the cooked-files, the other (mirrored) chunk will still be there... -Read _could_ be faster (what kind of controller?) Downsize (should be done to the managers above...): -Write is even slower (you're doubling the slow write-time of RAID-5) -The point of mirroring is usally to provide some higher sense of security, doing it on RAID-5 takes _a lot_ of that safty away. Thomas

NO RAID5 NO RAID5 NO RAID5 NO RAID5 NO RAID5 NO RAID5 NO RAID5 Red Valsen wrote: > > (Did that subject line grab you?) > > The lobotomized managers at my current worksite -- who make all manner > of uninformed (I could say ignorant, but I won't) decisions about > infrastructure acquisition, configuration and deployment - plan to ship > a system which will host an informixserver (which uses cooked files) > with a single RAID-5 partition comprised of half a dozen multi-gigabyte > devices -- in spite of advice to the contrary by highly (over)paid and > experienced consultants. Been there, welcome to the club! > Now, in attempting to find a way to mitigate the damage, the question > is: What use is it to mirror the instances' chunks within the same RAID > partition? Would this be helpful in any way? Not even a little! As Thomas pointed out it may save you if some dolt deletes one of the mirrored COOKED files. Beyojnd that no help at all. > We're using IDS 7.31UC-4 on Solaris 2.7/Intel (don't ask). Phew, I was sure you were going to insist I did. Art S. Kagel