NETGEAR is aware of a growing number of phone and online scams. To learn how to stay safe click here.
Forum Discussion
jamescordell
Dec 05, 2022Follower
Ready Nas 4220 No Volume Exists
Hi, We have a RN4220 and the volumes have disappeared, all else seems to be working fine and discs look ok and we can login to the admin panel ok. Is there any chance we can recover the data ...
SamirD
Dec 10, 2022Prodigy
Power down the unit and take the drives out and connect them all to a regular computer that has enough ports. Then boot the computer to a linux live cd. The volume if there is one, should be visible there and you can copy off the data.
StephenB
Dec 10, 2022Guru - Experienced User
SamirD wrote:
The volume if there is one, should be visible there.
Generally that is not the case. You need to take some manual steps to assemble the RAID volume and mount it. Also, you often need to install some linux tools (mdadm and btrfs are often not installed on live cds). Perhaps more importantly, if the volume fails to mount in the NAS, it will almost always fail the same way with the linux boot.
This troubleshooting can also be done in tech support mode w/o moving the drives (assuming you have the needed linux skills).
It would be useful to get the logs first, and diagnose what went wrong. If the volume is simply out-of-sync, the recovery generally is fairly straight forward - just forcibly assemble the RAID array. There can be some lost files (or corruption) due to lost disk writes.
But if disks have actually failed, the recovery is more difficult.
- SamirDDec 10, 2022Prodigy
I'm not sure if the 4220 is running os4 or os6, but for the older os4 units that are just running mdadm there are live cds that have worked for the intel ss4200-e that is also just using mdadm. I have the exact versions somewhere in my notes. But yes, if btrfs is in the mix, that's something only a more modern edition will have support for or the ability to add. It would be nice if someone where to make some sort of 'nas recovery' build just for recovering nas units. This is also one reason why I just run my drives jbod in a nas--so you can easily hook up the drive to a computer and get the data in case the nas itself has issues.
- SandsharkDec 10, 2022Sensei - Experienced User
The 4220 is a 12-bay rack-mount OS6 system, so putting all the drives in another computer is not a typical recommendation.
- SamirDDec 10, 2022Prodigy
Yeah, if it's fully populated that won't be an easy task. But if one is fully populating one of these, it's time to build a truenas setup on industry standard server hardware.
Related Content
NETGEAR Academy

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