[ReadyNAS NVX] Upgrade HDs to 3 TB

PeterWB wrote:

Current setup: 4x Western Digital RE3 Enterprise Edition 1 TB harddisks (model WD1002FBYS) Future setup: 4x Western Digital SE Datacenter Edition 3 TB harddisks (model WD3000F9YZ) [list=a] What will be the new storage capacity of my NAS? I've read a bit about the 8 TiB upgrade limit and the 16 TiB total limit, without using a factory reset. Will I indeed go from 4 TiB to 12 TiB? (I know the RAID array setup takes capacity, and the part about TB vs TiB is somewhat confusing, but what I'm meaning to say is will I go from a 4x 1 TB disk setup to a 4x 3 TB disk setup, or do I also lose capacity because of upgrade limitations).

You currently have a 3TB array. If you initially started with this configuration (that is, if your last factory reset was with all four 1TB drives in place), you can expand to a 3TB + 8TB = 11TB without performing a factory reset. Replacing all four 1TB disks with 3TB disks will give you a 9TB array; 9TB is less than 11TB, so you can do it without a factory reset.

PeterWB wrote:
If and when a factory reset is required to obtain an even larger capacity with the new HDs, do I lose all my data in the RAID array?

Yes. You'll have to backup your configuration and data, reset, then restore addons, configuration, and data in that order.

PeterWB wrote:
I know I need to upgrade per disk, and let the RAID rebuild before upgrading the next disk, in order to retain all my data. Do I need to power down the NAS before exchanging a disk, or can I leave the NAS running?

You should upgrade while the NAS is running. Pull one disk, wait for Frontview to tell you that a disk is missing, insert the new disk, wait for the array to rebuild.

Or... Backup all your data to something like a 4TB external USB drive. Power down the NAS, pull all the disks out and label them by slot number, insert all your new 3TB disks, factory reset, then restore your data from the USB drive. That'll be a LOT faster than rebuilding 4 times, plus you'll have a backup, plus you'll be starting with a 9TB array so you'll be able to expand to 4x4TB drives (or 4x5TB drives, if such things become available) later without another factory reset.

PeterWB wrote:
When the NAS can be left running: Is the NAS usable in the network (for reading / writing) when the RAID rebuilds, or is it better to take it off-line?

It's usable. Might be a little slow, though.

PeterWB wrote:
Any idea how long the rebuild per disk will take (hours, days)?

It gets slower as the array gets larger. I don't have an NVX, but I'd plan for the whole 3TB-to-9TB process to take a couple days.

PeterWB wrote:
Please confirm the new full capacity will only become available after upgrading the fourth and last disk.

The usable capacity is (approximately) the sum of capacities of all disks except the largest one, so...
4 x 1TB + 0 x 3TB = 1 + 1 + 1 = 3TB (current capacity)
3 x 1TB + 1 x 3TB = 1 + 1 + 1 = 3TB (after replacing 1 drive)
2 x 1TB + 2 x 3TB = 1 + 1 + 3 = 5TB (after replacing 2 drives)
1 x 1TB + 3 x 3TB = 1 + 3 + 3 = 7TB (after replacing 3 drives)
0 x 1TB + 4 x 3TB = 3 + 3 + 3 = 9TB (after replacing 4 drives)