[Feature Request] disk replacement for space enlargement

[scegg]

Hi.

Currently, if a user need to enlarge space by replacing disks, not adding, the procedure is:
1: Start the procedure
2: Replace one disk
3: Rebuild the new inserted disk with the data on other disks
4: Go to step 2 until all disks replaced
5: Space upgrading

While doing this, lots of time are required in step 3 and multiple disk reading operations also. But in most case of this scenario, the disks to be removed are healthy. We could read the data in this disk directly, rather than rebuild from others.

My request is making a new feature to do like this:
If there is at least on free slot for disk on this NAS:
1: Start the procedure
2: Locate a free slot
3: Prompt the user to insert a new disk into the free slot located.
4: Select one of the old disk (system automatically) and copy all the data from it into the new inserted disk of step 3. While performing this step, if any data copied from the old disk need to be changed due to any writing operating, it should be applied to the new disk also.
5: Prompt the user to remove the disk finished reading from step 4.
6: Set the slot related to step 5 as a free slot, go back to step 3, until all disks are replaced.
7: Allow an option to let user move the disk in the slot related to step 2 to the slot related to slot 5. While performing this step, volume readonly mode or downtime is acceptable.
8: Space upgrading

If this is a full house NAS:
1: Let user to attach a USB based HDD dock to the NAS.
2: Select one of the old disk (system automatically), prompt the user to relocate it to the USB dock, set the slot as a free slot. While performing this step, volume readonly mode or downtime is acceptable. This step is set for lowering the writing operating on a USB based disk.
3: Prompt the user to insert a new disk into the free slot.
4: Select one of the old disk (system automatically, the disk in USB dock should be the last one) and copy all the data from it into the new inserted disk of step 3. While performing this step, if any data copied from the old disk need to be changed due to any writing operating, it should be applied to the new disk also.
5: Prompt the user to remove the disk finished reading from step 4.
6: Set the slot related to step 5 as a free slot, go back to step 3, until all disks are replaced.
7: Let user to detach the USB dock.
8: Space upgrading

These steps are my suggestion, you could change them of course.

Please consider to make it possible. Thanks.