NETGEAR is aware of a growing number of phone and online scams. To learn how to stay safe click here.
Forum Discussion
Solved
Data Volume lost after disk replacement on Readynas Pro 6
Hi, I just ran into a serious problem, and I hope someone can help me. Currently my Readynas Pro 6 does not see any volume on the 6 disk X-Raid Array anymore. I walked past my NAS a couple of...
Yes, required for other than windows filesystems.
Obviously much cheaper than any professional recovery service.
Thanks StephenB,
If I understand X-Raid2 well enough (since yesterday..) than it is essentially a raid 5 configuration. With my limited knowledge I would say that as only one disk failed at any moment it should be possible to recover if I have not damaged anything seriously with the scrubbing. Unfortunately I have no idea where to start and obviously I am done experimenting at this stage.
I'll be happy to contact Netgear to see if they can help me, but I'll be just as happy if anyone from the community is able to show me what needs to be done. I hope it can be fixed.
Although you received notification of the second disk failure after being notified that the resync had completed, it is possible that the disk actually failed during the resync. I've certainly seen many users experience this pattern of events.
If you have no backup then you should try support as StephenB has suggested. There isn't anything you can do which isn't going to make data recovery more difficult.
If support won't help then I guess you can look for other data recovery services.
Thanks vandermerwe,
I'll contact Netgear, I truly hope they can help me out
Your message made me think however: Since my problem I have been thinking to setup a second 6 bay system as hot standbye or as a live backup system.
But if it is common that two disks fail at the same time, and resync is often not succesfull, and if the chances for a simple recovery with a raid5 solution are slim therefore, wouldn't it be much safer to buy a simple dual disk NAS system and set it up only to mirror the other disk? In that case the chance for losing all data would be the chance that two disks out of two fail at the same time. In my 6 bay X-raid/Raid5 configuration the chances that two disks fail at the same time is 15 times higher (if my chance calc is right). I had never thought about it, but to me that sounds too risky (now). Maybe it doesn't justify the capacity loss of a simple mirrored setup with only two disks or the additional investment in more expensive 6 bay systems. But moreover, doesn't the much increased risk of data loss put X-Raid aside as a reliable solution for data storage?
With higher numbers of disks Xraid with dual redundancy (or RAID 6) is what most here would recommend.
A lot of us have a dual nas setup, using replicate or other synchronisation
Hombibi wrote:
Since my problem I have been thinking to setup a second 6 bay system as hot standbye or as a live backup system.
But if it is common that two disks fail at the same time, and resync is often not succesfull, and if the chances for a simple recovery with a raid5 solution are slim therefore, wouldn't it be much safer to buy a simple dual disk NAS system and set it up only to mirror the other disk? In that case the chance for losing all data would be the chance that two disks out of two fail at the same time. In my 6 bay X-raid/Raid5 configuration the chances that two disks fail at the same time is 15 times higher (if my chance calc is right). I had never thought about it, but to me that sounds too risky (now). Maybe it doesn't justify the capacity loss of a simple mirrored setup with only two disks or the additional investment in more expensive 6 bay systems. But moreover, doesn't the much increased risk of data loss put X-Raid aside as a reliable solution for data storage?
First of all, though two disks failing at around the same time does happen, I wouldn't call it "common". Also, the chances are the same if you have a 6-bay NAS running xraid or if it is running jbod. What changes is the impact of those failures. If you were running jbod, then one failure would lost 1/6 of your data, and two failures would have lost 1/3. Running xraid, 1 failure loses nothing, but 2 or more lose everthing.
Math aside, recovery of a RAID array can be difficult. One option is to lower the odds, and run RAID-6 (or maybe RAID-10, or multiple RAID-1 volumes) as vandermerwe suggests. You can also run jbod on the backup NAS, which makes it less likely that you'd lose everything. I've taken the latter strategy (I have 3 copies of all my data, and my backup NAS(s) are using jbod to simplify recovery. The main NAS uses xraid/RAID-5.
So there's more than one approach here. However, I think that if most of the experienced users here had to choose between a single NAS with RAID-6, or a main NAS with RAID-5 + a backup, they'd vote for RAID-5 + backup.
Please send me the logs (see the Sending Logs link in my sig).
NETGEAR Academy
Boost your skills with the Netgear Academy - Get trained, certified and stay ahead with the latest Netgear technology!
Join Us!
