RAID 5 Repair and recover

[babhiker]

I have a NUUO NVRmini2 NE-4080 video recording NAS server. It has 4 disks configured as RAID 5. RAID status was critical this morning. Disk 4 was dropping out, I could see in the logs. I was going to replace disk 4 to try to reseat the drive but... Here is the really dumb part.. I removed disk 1 instead. Am I totally screwed as far a getting any data back? Now drive 1 shows up as a spare . When I replace drive 4 with a new drive(on order) is there any chance of recovering i.e. somehow returning drive 1 to it's original status?

Thanks for any input!

 

[Ijack]

If the array is still working, change drive 1 from a spare to part of the array. (From what you say all 4 must ave been part of the arry originally) Pray that the failing disk lasts long enough to allow the array to rebuild. Once the array has rebuilt you can pull the failing disk and replace it.

If that doesn't work then you probably have to rebuild the array from scratch and restore your data from your backups.

 

[drtweak]

Yea just replace Disk 4. This is the beauty of a RAID 5. In your case you have 4 drives. 1 drive is a parity drive (Or the Spare/Hot Swap drive) This is the drive that takes over once 1 disk has failed. So when you removed disk 1, I'm assuming disk 4 was the spare drive before (Or another drive) and it started to rebuild since it though Disk 1 was gone but since disk 1 is good and you put it back in it made it the new spare.

I would wait till it rebuild first which is what is is probably doing. Then I would just yank out disk 4 and replace it.

Also is this a full blow server or just a NAS Box? If its a server what OS are you running and kind of RAID card? If its a server and if it is running a Hardware RAID then i would restart it, and then at startup it should give you a Key Combo to press to enter the Raid config, and check it form there.

 

[TyrOd]

HOLY CRAP, NO do not take any of the above advice.
Your array is CURRENTLY in a DEGRADED state with at least 1 other drive failing or unstable.

DO NOT attempt any rebuilds. You need to in this order:
1: Make images of ALL drives in the array EXCEPT disk4
2:Attempt to bring the system back online with 3 disks in a degraded state.
3: Attempt a rebuild with the 3 image drives + spare.
4: If steps 1-3 are not successful, seek a professional data recovery lab to recover the data and expect to pay $1k+ for data recovery.

 

[TyrOd]

Yea just replace Disk 4. This is the beauty of a RAID 5. In your case you have 4 drives. 1 drive is a parity drive (Or the Spare/Hot Swap drive) This is the drive that takes over once 1 disk has failed. So when you removed disk 1, I'm assuming disk 4 was the spare drive before (Or another drive) and it started to rebuild since it though Disk 1 was gone but since disk 1 is good and you put it back in it made it the new spare.

I would wait till it rebuild first which is what is is probably doing. Then I would just yank out disk 4 and replace it.

Also is this a full blow server or just a NAS Box? If its a server what OS are you running and kind of RAID card? If its a server and if it is running a Hardware RAID then i would restart it, and then at startup it should give you a Key Combo to press to enter the Raid config, and check it form there.

Dude, first of all there is NO "spare" drive.

The PARITY data is distributed across all drives in a RAID5 array, so unless he had the system setup from the beginning as RAID5+1 hot spare, he is in a REALLY bad situation to attempt any kind of rebuild.

 

[USAFRet]

This is when you blow away the entire RAID array, rebuild it, and bring up the data from your backup.

 

[popatim]

USAF Retired and I are of the same mind. Losing an array should never be an 'OMG' situation, merely an inconvenience. Especially since an array never replaces the need for a backup.

TyrOd also offers correct advice especially if there are no backups. If there are backups. power off the nas, insert the drives back into the exact same slots. power up the nas. It should power up in a degraded state with the 3 good drives, now you can replace the bad drive and initiate the rebuild.

If you dont have a backup and the files are important then step 1 is to protect the data and you do that by imaging the 3 drives. I would attempt the 4th drive too but 3 would be the minimum. Don't do anything else until you get that done, dont even power them up.

 

[drtweak]

Yea just replace Disk 4. This is the beauty of a RAID 5. In your case you have 4 drives. 1 drive is a parity drive (Or the Spare/Hot Swap drive) This is the drive that takes over once 1 disk has failed. So when you removed disk 1, I'm assuming disk 4 was the spare drive before (Or another drive) and it started to rebuild since it though Disk 1 was gone but since disk 1 is good and you put it back in it made it the new spare.

I would wait till it rebuild first which is what is is probably doing. Then I would just yank out disk 4 and replace it.

Also is this a full blow server or just a NAS Box? If its a server what OS are you running and kind of RAID card? If its a server and if it is running a Hardware RAID then i would restart it, and then at startup it should give you a Key Combo to press to enter the Raid config, and check it form there.

Dude, first of all there is NO "spare" drive.

The PARITY data is distributed across all drives in a RAID5 array, so unless he had the system setup from the beginning as RAID5+1 hot spare, he is in a REALLY bad situation to attempt any kind of rebuild.

No you're right. I'm just use to RAID 5 always have a Hot Spare because the only time I deal with them are in servers and we ALWAYS have a hot spare. Would be stupid not to on a RAID 5 or and RAID to begin with. But I just assumed it was a hot spare since when the added back in Disk 1 it made that drive a Spare drive. From my experience with RAID 5 if you have a spare drive, and yank a drive that isn't the spare, it then rebuilds using the spare and even if its for a split second it then makes the spare part of the RAID and then the other drive becomes the spare, so I just assumed he had a spare setup already. But then again I'm always dealing with High end Dell PERC Cards.

 

[popatim]

Yeah, not having a hot spare make little sense to me and I just dont get why they make 4 drive NAS & direct attach raid units but not 5 or 6. (8's are just too dang expensive.) 3 drive raid5 makes as much sense to me as not having a hotspare. Not even something I would consider. LoL.

 

[Philip_Booth]

Raid Recovery is the first tool to automatically detect the type of the original RAID array while still allowing for fully manual operation. Raid Recovery is no doubt a highly valuable tool for users of all types of RAID array. Raid Recovery gives top priority to your data, allowing you to recover and back up all files from the corrupted array before attempting to fix it. You can store the files on another hard disk or partition.

 

[Ijack]

Wow - that reads just like an advertisment! Do you have any connection with the publishers of that software by any chance?

Edit: Being the curious sort, I fed your post into Google. Look at what I found on the web page of the publishers of this software!

...Raid Recovery is the first tool to automatically detect the type of the original RAID array while still allowing for fully manual operation. Raid Recovery is no doubt a highly valuable tool for users of all types of RAID arrays, whether hardware, native, or software
....
Raid Recovery gives top priority to your data, allowing you to recover and back up all files from the corrupted array before attempting to fix it. You can store the files on another hard disk or partition, use a recordable CD or DVD, or even upload the files over FTP.

Looks familiar? 😉

I don't know what the software is like, but their marketing stinks.

 

[TyrOd]

Wow - that reads just like an advertisment! Do you have any connection with the publishers of that software by any chance?

Edit: Being the curious sort, I fed your post into Google. Look at what I found on the web page of the publishers of this software!

...Raid Recovery is the first tool to automatically detect the type of the original RAID array while still allowing for fully manual operation. Raid Recovery is no doubt a highly valuable tool for users of all types of RAID arrays, whether hardware, native, or software
....
Raid Recovery gives top priority to your data, allowing you to recover and back up all files from the corrupted array before attempting to fix it. You can store the files on another hard disk or partition, use a recordable CD or DVD, or even upload the files over FTP.

Looks familiar? 😉

I don't know what the software is like, but their marketing stinks.

That account is a bot that's been on every data recovery thread and article here for a few weeks at least.