I am doing a resync on a RAID6 array and I am looking at some 2 days to complete. I looked here for hints on how to speed it up, but I have, instead, managed to slow it down!
HW details are: 10x 4TB WD Black HDDs (one died so resync is due to this) Core2Quad, ASUS P5K Deluxe with 8GB RAM
What are the best params (VALUE) to use for this config and/or how do I calculate these?
Hint 1 - MIN / MAX SPEED LIMITS:
echo VALUE > /proc/sys/dev/raid/speed_limit_min (I set to 90000) echo VALUE > /proc/sys/dev/raid/speed_limit_max (I set to 900000)
Hint 2 - READ AHEAD:
blockdev --setra VALUE /dev/md0 (set to 32MB / 65536)
Hint 3: STRIPE-CACHE SIZE (how do I find system_page_size? I set to 32MB / 32768 and have not seen OUT OF MEMORY error):
memory_consumed = system_page_size * nr_disks * stripe_cache_size echo VALUE > /sys/block/md0/md/stripe_cache_size
I have disabled NCQ and enabled internal bitmap before starting resync so these steps are working.