Tom Bishop wrote:
So I have been playing with a RAID 10 f2 ( 2 disks far layout) setup...thanks for all of the advice..Now I am playing with the format and want to make sure I have it setup the best that I can, my raid was built using the raid 10 option with 2 disks with the layout=far, chunk size 512....now I read all of the docs I could find about format and stride and stripe size and this is what i came up with...
mkfs -t ext4 -E stride=128,stripe-width=32 /dev/md0
Someone let meknow if this looks right, but since i only have two disks to get my stride 512/4k=128 and then to get my stripe 2/2*128/4=32
I have this in my notes for ext2/ext3 filesystem under raid 5. You will have to see how your layout differs from raid5 in terms of distribution of data across the disks.
# the optimal stride is given by: # # chunk size # stride = ---------- * ( num disks ) # block size # #
Here is a framework of a script to test performance of various chunk sizes (came off of some webpage a while ago). Optimal chunk size will of course depend on your application and the size of your writes and files.. # # EXT2BLOCKSIZE=4096 # or 1024 or ??? # for CHUNKSIZE in 4 8 16 32 64 128 256 512 do stride=$(( $CHUNKSIZE * 1024 / $EXT2BLOCKSIZE )) .. .. create new /etc/raidtab and run the test .. mke2fs -b $EXT2BLOCKSIZE -m 1 -Rstride=$stride /dev/mdxx .. mount /dev/mdxx ..configurations # whatever test .. tiobench bonnie dd .. done # #