Drive Size Increase


I upgraded the drives on a DL4100 RAID-10 from 4 4TB drives to 4 6TB drives. I did Hot Swaps one at at time and the dew drives were rebuilt.

The unit is up and running and all the data is accessible. When I go to Storage->Disk Status it show 4 6TB drives in Good condition and perfect temperatures. But when I look at Storage->Raid Volume_1 Shows RAID10 with 7.92 TB.

I’ve rebooted it and still thinks it has the same old space of the 4TB drives. Home still also shows the old spape available

Since I use RAID 10 I figured it would automatically go up to the 12TB capacity in RAID 10. I have looked around and haven’t found a place to increase the size.

If i go into RAID configuration and just re-select RAID 10, it warns all data will be destroyed and i don want to have to restore everything.

anyone know how I can get it to increase Volume_1 without losing everything and having to restore?


raid mirrors/duplicates/protects the files if one drive goes out. The capacity of the raid will always be in relation to the smallest drive. So in your case as you found out the extra capacity is wasted.

Some RAID controllers offer migration, but I think you will need to copy your data off and build a new array to 12tb


I did more research and saw that you can add a Volumes_2 with the extra space but only option seems to be as Spanning.

WD has no option to increase the drive partition size. I verified this with WD Tech Support. The only way to use the extra space is to redefine your RAID 10 which erases it and the only option is to restore all your file.

I was using 7.5TB so that takes a long time to restore!

There is software available to resize drive partitions and I assumed that WD would resize them after increasing the all the drives to larger drives.

I wasted two days installing each drive individually (Hot Swap) with the expectation that in the end there would be a way to automatically increase Volume_1 without a full restore,

Had I known that, I would have to re-initialized the RAID 10 to increase the size, I would not have wasted two days doing the How Swaps.

It would be pretty simple for them to increase the partition size without a restore, but I guess they are too lazy to do it, don’t want to pay a license fee to use someone else’s partitioning software or just want to sell more external drives.

Just seems like a big waste to time to not be able to increase the drive partition size on the fly and force you to have well over 24 hours of down time restoring your NAS!


You have to accept the fact that this is a low cost NAS device. A server quality hardware RAID card cost as much as this box.


I own EaseUS Partition Manager for Windows which costs $59.95. I know I bought it on sale for much less than that.

A bulk license would probably go for much less than $10 or $20 dollars. I would be happy to have paid an extra few bucks and not have to be going through a restore now and have the Partition Manager added the space on the fly when larger drives are installed.

I’m already into 26 hours of restoring and estimate it will be another 4 to 6 hours to fisnish.

i would have gladly paid a few extra bucks to have the capability to increase volume size without having to re-initialize the volume and have to do the restore.

It’s a very disruptive process. Hopefully WD does something in the future to address this problem!


33 1/2 hours later my restore is finally done. It would have been so much nicer if WD would have automatically taken care of partitioning the drives to accurately use the new full size without having to re-initialize and restore.

I went from four 4TB WD Red Pros to four 6TB WD Red Pros in a DL4100. Originally I did Hot Swaps and allowed the old drives to copy from the 4TB to the 6TB, but in the end I still had to re-initialize and restore 7.5TB of data to the new drives.

It would have been really nice if the added space was automatically added without the restore.

Very disruptive for those who use this in a business environment!