Hi Dave, Thank you for the response. Is this still the case even though the raid card is presenting the raid60 array as a large single 723TB drive? Thanks, Alan > On Feb 3, 2020, at 2:59 PM, Dave Chinner <david@xxxxxxxxxxxxx> wrote: > > On Mon, Feb 03, 2020 at 01:48:20PM -0800, Alan Latteri wrote: >> Hello, >> >> In an environment with an LSI 3108 based HW-RAID60, 256k stripe size on controller, 5 spans of (10data+2parity) disks. What is the proper su & sw to use? Do I do sw to the underlying 10 data disks per span? The top level 5 spans or all 50 data disks with the array? Use case is as a file server for 20-60 MB per frame image sequences. >> >> i.e >> >> 1) sw=256k,sw=10 >> 2) sw=256k,sw=5 >> 3) sw=256k,sw=50 > > A HW RAID6 lun in this configuration behaves (and performs) like a > single disk, so you're actually putting together a 5-disk raid-0 > stripe with a stripe unit of 2560kB. > > i.e. for consistent performance and allocation alignment for large > files, you want to do full RAID-6 stripe writes to each lun. Hence > you want the filesytsem aligned to the first disk in each of the > RAID-6 luns and to size allocations to full RAID6 lun width, not > random individual drives in the RAID-6 luns. > > IOWs: > > sw=2560k,sw=5 > > Cheers, > > Dave. > -- > Dave Chinner > david@xxxxxxxxxxxxx
