As the title states, I currently have my Synology NAS with a single 4TB drive in it. I now wish to expand this with another 4TB drive. If I expand the volume (it's currently setup as SHR) will the initial disk be erased? I know it says "existing data will be erased" when you select the new drive, but I'm not sure if it means only on the new drive or both the new and the existing drive.
Synology – Will Expanding Hybrid RAID Delete Data on Initial Disk?
network-attached-storageraidsoftware-raidsynology
Best Answer
No the existing data will not be erased when you add a disk to the SHR array. The message is simply saying the new drive being added will be formatted.
Your data and applications will actually remain available during the expansion process; there is no need at all to even stop using the NAS whilst SHR Vertical Expansion is taking place.
That said - before any type of RAID manipulation (of any flavor) you should backup first.
Finally it is probably worth pointing out that if you are using two equally sized disks there is no point at all using SHR over RAID1 - indeed you should use RAID1 as SHR will incur an overhead in both read and write speeds compared with RAID1.
The real advantage of SHR comes when using odd sized disks.