>> I've always wondered if there's a maildir split >> specified out there that applications could utilize... >> where n is your split width... tmp/n, new/n, cur/n. > > what about shifting this problem to the storage layer? > Apart using SSDs, what about using having a striped array as a RAID 1+0 > layout, in order to have some redudancy as well?
Adding IOPS, tuning dirhash and whatnot definitely work up to a certain point. Sometimes you'll blow out your backup programs and other tools at various points along the way till you're again bound by too many files in one dir or have hit the cpu/ram wall for it all.
