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RAID Resync#


Improve Speed#

If you make these changes, your RAID resync/build times will improve substatially.


Your NAS will be incredibly slow and nearly unresponsive after these changes.


  1. Open Storage Manager
  2. Go to Storage Pool
  3. Go to Configurations
  4. Select Customize
  5. Set Min to something high like 300 or 600
  6. Set Max to something ridiculous like 1500 (it'll likely never go that fast)

Command Line#


You may have a different number instead of md2 for your main array. Use cat /proc/mdstat to find out your array number.

  1. SSH into your NAS
  2. Elevate to root with sudo -i if you don't want to type sudo before every command
  3. Run echo 32768 > /sys/block/md2/md/stripe_cache_size if you have a lot of RAM. If you have the default amount of RAM, this might not work well. You can use any power of 2 though, such as 16384 or 8192. I don't recall what the default is, but I think it's only 4096.
  4. Run blockdev --setra 65536 /dev/md2
  5. Optional: Run echo max > /sys/block/md2/md/sync_max (in my case this was already set to max and not needed, however)

You can also play with disabling NCQ during the rebuild, but I found it helped basically none so returned that to default.