> My testing has lead to some questions Could you post some figures? For instance, what's the file system throughput to the raw disc versus a two-component Level 1 RAID (with stripe size equals file system block size)?
> I think it's possible, even if you have the raid card in jbod mode, I don't know of any other modes the card (3081E-R) has. > Is it possible for you to set up a test with raid5 using a different sata > or sas interface card? Difficult. I don't have any other machine with SAS (except one identical to the to-be file server minus the data discs). I could try a desktop machine with two or three SATA drives attached to the mainboard. > I've found that for high work loads this card just stops generating > interrupts for no apparent reason. > I wonder if you're suffering from a similar, but not quite so fatal, kind of > issue with your raid controller? How can I check that? > while the spsu size was right, the sector boundaries which defined the > stripe might not be the same as the blocks being read from and written to > on the filesystem itself. I seriously hope that's not true. I think if the partition is aligned, the file system blocks are aligned. Can some file system expert please comment on this? > raid5 will always be slower than raid1 Why? If the stripe size equals the fs block size, I don't see why that should be the case. > I kno[w] how frustrating it can be to try and figure out why something isn't > working as expected. Yes. Of course, that's my job, but it gets frustrating after weeks without clues of improvement.
