I'm having some issues expanding a RAID 5 array on a Synology DS413. The drive has gone from 3 x 3TB WD Green drives to 4 x 3TB. I started an expansion operation and it's been stuck at about 60% and extremely slow speeds for a week (about 350Kb/s when I check
/proc/mdstat). I've tried increasing min/max speed limits and stripe_cache_size but it didn't change the actual speed.
The drive is near unusable while the expansion is running, transferring files out maxes out at 400Kb/s. I think the issue is related to bad sectors on Disk 1, when I try and run a SMART test on the drive it gets stuck at 90%.
So because I can't get data out of the disk and the RAID expansion will take over a month, I'm wondering if there's a way to stop the expansion? If I force reboot the disk by disconnecting power, will it corrupt the drives? Are there any other options that people know of?