… : 5 Failed Devices : 0 Spare Devices : 1 Layout : left-symmetric Chunk Size : 64K Name : 001F33EABA01:2 UUID : 01a26106:50b297a8:1d542f0a:5c9b74c6 Events…:51:11 2011 Raid Level : raid5 Raid Devices : 6 Avail Dev Size : 5851089777 (2790.02 GiB 2995.76 GB) Array Size : 29255447040 (13950.08…
Post: RAID throughput on FusionIO
March 24, 2010 By 7 Comments
… you can get creating RAID as: mdadm –create –verbose /dev/md0 –level=10 –layout=n2 –raid-devices=4 –chunk=64 /dev/fioa /dev/fiob /dev/fioc /dev/fiod In this case for all modes use 64KB chunk size ( different chunk sizes… echo “====== testing $blksize in $threads threads” echo PARAMS $size $mode $threads $blksize > sysbench-size-$size-mode-$mode-threads-$threads-blksz-$blksize for i…
Post: Aligning IO on a hard disk RAID – the Theory
June 9, 2011 By 18 Comments
… default are bigger in size – I would often see see 64KB (mdadm default chunk size) or 128KB stripe unit size so in these cases… alignment example, let’s assume we have a RAID with 256k stripe element size and a misalignment in partition table – partition /dev… a stripe width. RAID level, number of disks and the size of a stripe element set the stripe width size. In case of…
Post: EC2/EBS single and RAID volumes IO benchmark
August 6, 2009 By 14 Comments
…/md1 –chunk=256 –level=raid1 –raid-devices=2 /dev/sdm /dev/sdl and mdadm -v –create /dev/md2 –chunk=256 –level=raid0 –raid-devices… 16; do echo PARAMS $size $mode $threads > sysbench-size-$size-mode-$mode-threads-$threads ./sysbench –test=fileio –file-total-size=$size –file-test-mode=$mode…
Comment: Aligning IO on a hard disk RAID – the Theory
June 9, 2011 By 18 Comments
… create software RAID, there’s little difference what is the physical sector size since you want to align to md chunk size right? @Roman – while this depends a lot on the workload and the RAID controller, I think it’s fine to have a relatively small stripe size as long as IO…
Comment: RAID throughput on FusionIO
March 25, 2010 By 7 Comments
RAID 10,f2 is generally considered to be the overall fastest Linux RAID10, so you might want to try that. Also, as of mdadm 3.1.1, default chunk size is 512K rather than 64K, so maybe that’s worth trying.
Comment: Setting up XFS on Hardware RAID -- the simple edition
December 16, 2011 By 9 Comments
… size, in this case 256k. Does this mean that the RAID controller is not going to cut the data up into smaller chunks, say 4 64k chunks and write them in parallel the across two drives? In my mind and what I have read, increasing the RAID stripe size…
Post: Innodb Fuzzy checkpointing woes
May 10, 2006 By Leave a Comment
…flushing of dirty pages happens gradually in small chunks so database load is very even. This … your database is small (ie only size of allocated buffer pool size) this might never happen. … at shared MySQL virtual hosting and powerful RAID system may have very different performance properties.Â…
Comment: Aligning IO on a hard disk RAID – the Theory
June 9, 2011 By 18 Comments
… only tool that uses “stripe size” to call what other tools call stripe element, stripe unit or chunk. Here’s definition from the manual v1.0 (2006): Stripe Size: The stripe size specifies the size of the segment written to each disk in a RAID configuration. You can set the stripe size to…
