INFORMATION: RAID 5 Add Disk Rebuild Time

[raotor]

This is just for informational purposes only and may help people thinking about expanding their systems decide if/when they should do it.

I have a ts 509 Pro with firmware version 3.1.2.

I have 4 1.5Tb HDD's and have just expanded the array with a fifth HDD using the "Add Disk" option.

The expansion process took around 81 hours to complete! The percentage progress given I think was only about half of the actual progress because when I last checked during the expansion it was showing 48%. However, the process completed just a few hours later - so I think the progress percentage figures are approximately half of what they really are.

Nevertheless, 81 hours to complete. Assuming at some point in the future I want/need to expand the entire array (i.e. replace all 5 HDD's with larger capacity units) and assuming the capacity expansion process takes a similar time to complete for each disk as the "Add Disk" option, then you're looking at over 400 hours to do this!

Food for thought considering that the volume is read-only during the expansion process - not a problem for me as I use mine for media streaming, but perhaps more critical to those who use theirs for other things.


t

[PC-fre@k]

Just added a 2TB disk to a 3x2TB RAID 5 .
Started yesterday 20:00, now 26 hours later, 12 percent... So, if I should double this, 26 hours 24 percent, then it would take about 110 hours to complete this? that freakin 4,5 Days!

[Don]

Look at the Increase raid rebuild speed link in my signature. This might help.