NETGEAR is aware of a growing number of phone and online scams. To learn how to stay safe click here.
Forum Discussion
NARKOSIS
Jan 14, 2020Aspirant
Expanding Storage on RN3138 Question
Good afternoon, Our company is looking to expand our 3TBx4 NAS. We are running RAID-X (Raid5). The documentation mentions the drives are hot-swap enabled. Does that mean we can just remove (say) ...
- Jan 14, 2020
NARKOSIS wrote:
Does that mean we can just remove (say) the fourth drive, install a 6TB drive and its good to go?
Basically yes.
You should make sure your backup is up to date before manipulating disks, as the array isn't redundant during the RAID resync, and the process will fail if there are latent disk issues.
Then hot-swap the first disk and wait for the resync to complete.
When it does, hot-swap the second, and wait for it. There will be two resyncs needed (the second one will likely be called "reshaping". So be sure it is complete before moving on to the third.
Also, the volume won't expand until the second disk is replaced and fully resynced. The third and fourth disk upgrades will also expand.
The capacity rule is "sum the disks and subtract the largest". That will give you the size in TB (1000*1000*1000*1000 bytes). However, the NAS actually reports TiB (1024*1024*1024*1024). Google can convert this for you btw - for example, try entering 12 TB in TiB into the Google search bar.
NARKOSIS wrote:
Do all of the drives need to be the same size?
As is hopefully clear from the first response, no.
Personally I'd upgrade only two of the drives, and upgrade them with larger models. That allows upgrades to be done more cheaply later (and often more cheaply now).
For instance, upgrading four disks to 6 TB Ironwolf Pros would cost about $720 USD and gain you 9 TB of capacity. Upgrading two disks to 12 TB Ironwolf Pros would actually cost you a bit less at the moment (about $650 USD) - and you'd end up with the same volume size. Plus when you need to upgrade again, you can replace one of the 3 TB drives with another 12 TB one, and gain another 9 TB. A lot cheaper than upgrading all four every time.
That's just an example, obviously if you prefer different disks the pricing will be different. But I do recommend using either NAS purposed (WDC Red or Seagate Ironwolf) or enterprise-class drives.
StephenB
Jan 14, 2020Guru - Experienced User
NARKOSIS wrote:
Does that mean we can just remove (say) the fourth drive, install a 6TB drive and its good to go?
Basically yes.
You should make sure your backup is up to date before manipulating disks, as the array isn't redundant during the RAID resync, and the process will fail if there are latent disk issues.
Then hot-swap the first disk and wait for the resync to complete.
When it does, hot-swap the second, and wait for it. There will be two resyncs needed (the second one will likely be called "reshaping". So be sure it is complete before moving on to the third.
Also, the volume won't expand until the second disk is replaced and fully resynced. The third and fourth disk upgrades will also expand.
The capacity rule is "sum the disks and subtract the largest". That will give you the size in TB (1000*1000*1000*1000 bytes). However, the NAS actually reports TiB (1024*1024*1024*1024). Google can convert this for you btw - for example, try entering 12 TB in TiB into the Google search bar.
NARKOSIS wrote:
Do all of the drives need to be the same size?
As is hopefully clear from the first response, no.
Personally I'd upgrade only two of the drives, and upgrade them with larger models. That allows upgrades to be done more cheaply later (and often more cheaply now).
For instance, upgrading four disks to 6 TB Ironwolf Pros would cost about $720 USD and gain you 9 TB of capacity. Upgrading two disks to 12 TB Ironwolf Pros would actually cost you a bit less at the moment (about $650 USD) - and you'd end up with the same volume size. Plus when you need to upgrade again, you can replace one of the 3 TB drives with another 12 TB one, and gain another 9 TB. A lot cheaper than upgrading all four every time.
That's just an example, obviously if you prefer different disks the pricing will be different. But I do recommend using either NAS purposed (WDC Red or Seagate Ironwolf) or enterprise-class drives.
- NARKOSISJan 14, 2020Aspirant
Thanks for the detailed explanations/recommendations! Is there a preferred/recommended order to replace them? Or does it matter? IE, Replacing the first on the Left->Right (1,2,3,4), or Right->Left (4,3,2,1)? And yes, we are looking at the Ironwolf drives.
- StephenBJan 14, 2020Guru - Experienced User
NARKOSIS wrote:
Is there a preferred/recommended order to replace them? Or does it matter? IE, Replacing the first on the Left->Right (1,2,3,4), or Right->Left (4,3,2,1)?
It doesn't matter. If the existing drives weren't purchased at the same time, then perhaps replace the oldest first?
- SandsharkJan 15, 2020Sensei - Experienced User
Oldest or any showing SMART errors first.
Related Content
NETGEAR Academy

Boost your skills with the Netgear Academy - Get trained, certified and stay ahead with the latest Netgear technology!
Join Us!