I'm looking for some advise on tuning. I have a server with 20 disks behind an LSI 9271-something. They are currently exposed as 20 individual raid0 with a "strip" size of 1MB, and assembled into an mdraid, meta 1.2, layout 10 format f2, with a 1MB chunk size and formatted using ext4 -T largefile. To date, this has given me the best numbers when reading some 10,000 files (total size: about 2.5TB) sequentially or in parallel. I can't seem to get better than about 1,800 MB/s read speeds though. I *should* be able to get closer to 3,000 based on what the drives are capable of. Quite some time ago on this very hardware I saw a sustained 2,750 MB/s but I don't remember how I got there. readahead values have been adjusted, I/O scheduler, etc... all played with with some benefit but nothing huge. What should I be looking at here if I want the best possible read performance? I don't want to give up some measure of redundancy. -- Jon -- 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
