Prevention is good

Every now and then, people plan and go to great lengths figuring how to do data recovery before the actual data loss occurs.

What type of file system does the ix2 use with hard drives? For safety, I’d like to know how to recover data from the drives if the ix2 fails. I do not like the idea of relying on some hidden proprietary format that requires the ix2 to be able to retrieve my data in case of failure.

Anyone know how to read the disk formatted by the ix2 from a PC running any operating system?

There is no hidden proprietary format actually. Lenovo/Iomega uses run-of-the-mill Linux software and filesystems. However, the great confusion ensues little further in the discussion, mixing up filesystems with RAIDs, RAIDs with backup, single-disk RAID1 with a single partition, you name it.

Well, let’s spell it out

  1. Any NAS would use this-or-that form of RAID.
    1. Even if you have a single disk in a multi-bay NAS, it will have a single-disk RAID, most likely RAID1, to avoid changing data format if you add a second drive.
    2. Furthermore, if you have a single-bay NAS, it is still likely to have a single-disk RAID, to achieve compatibility across the entire model lineup (and specifically the ability to move the drive to the multi-bay model).
  2. Most modern NASes use one of the standard Linux filesystems, XFS, EXT3, EXT4, or BTRFS.
  3. If there is no damage to the data on disks, or the damage is minor, and assuming skilled operator, a properly configured Linux PC will read the data if all disks are connected at the same time.

But, the most important question here is: if one plans for data recovery before the actual loss, why do not have a backup instead of recovery?

 

Advertisements

ix4-200d unsuccessful drive replacement

Someone had to go to a data recovery center when his Iomega StorCenter ix4-200d has a rebuild failure

I have a StoreCenter ix4-200d [with 4 disks in RAID10] that had a drive failure. I … replaced the damaged drive. On restart the screen on the StoreCenter said “Drive 1 requires overwrite confirmation“, but when I go into the dashboard, there is no message for confirmation, and it has not lost all storage folders and shows 0 data stored.

… and that’s actually the end of story. Further troubleshooting attempts in earnest require the drives to be out of the NAS, no matter if you use Linux and mdadm, or Windows and data recovery software. However, as it often happens, some tinkering with mdadm was attempted, unfortunately with no effect, but fortunately without any ill side effects. The story ends happily, although not cheap

 

Yes i found a solution… I did send my storecentre to a recovery service centre and they managed to restore the data 100%…the total cost for this recovery €3000 !!!

That may seem tad high for a 4 disks in RAID10, as the drives were still readable and probably did not both require extensive mechanical work. The corresponding Home NAS Recovery license would have been little short of $200, plus a cost of four replacement drives.

IX4 falling apart

This documents a typical sequence of multiple drives failing in a RAID5, this time in Iomega ix4-200d.

I’ve received an automatic email from the dashboard saying

Data protection is being reconstructed. Data is available during this operation, however performance may be degraded.

After that, the NAS started ‘Data recovery procedure’ [and then came another message]

Drive number 1 encountered a recoverable error.

[and] NAS started recovery procedure from the scratch. Even though that mentioned drive has failed, everything worked fine untill yesterday [when] new message … said

Storage failed and some data loss may have occurred. Multiple drives may have either failed or been removed from your storage system. Visit the Dashboard on the management interface for details.

Is there any way to recover at least some data if it is NAS that failed?

Depending on the condition of the disks, Home NAS Recovery may or may not be able to extract data from it.

Maybe there was a spare involved, as data protected is being reconstructed in a RAID5 can only refer to a rebuild of the array. The rebuild happens either when a defective disk was replaced or when a hot spare kicks in after one of the active array disks fails. There is another variation to that tune, not really obvious, which is a transient failure causing one of the disks to drop out of the array momentarily, then report back online and be accepted back in the array.

Anyhow, while rebuild is in progress, it turns out the second drive in the array is unreadable. This halts the rebuild. The error is at first deemed recoverable, and the rebuild is retried. However, the error recovery is not successful and the second disk (#1) drops offline. With two drives offline, the data is no longer accessible.

For our data recovery software, the logical reconstruction is not a problem given that the disks are still readable enough. This may be a problem though. In worst case, the disks need to be cloned to a blank new disks, and clones then used for recovery. The NAS will not accept the clones because it already has recorded the disks as “failed”, and cloning the entire disk content also clones the “failed” marks for respective disks.

The case for the Linux way

This case looks like it can be solved with Linux fairly easy

I own an Iomega storcenter ix2-200, with several shares… Shares show up as empty, on my pc as well as on the webinterface. … However, the webinterface also indicates that there 1.2 TB of data (the blue indicator), which should be the real size. Therefore, I assume the data is still present, but something has been messed up. Does anyone know / have suggestions how I can regain access to my data?

Shares not containing data is obviously bad. However, the case as a whole does not look that bad, because the volume is still indicating 1.2 TB in use, so the data is still there somewhere. Most likely, attaching the disk set to a Linux PC will allow to copy the data away. This should not be difficult given it is only two disks. Then, some Linux chmod may be in order to override any possible access restrictions, and the data should be there for the asking.

SHR on two identical disks

The set of questions from here, while SHR-specific, applies to NETGEARs X-RAID as well.

I have a DS213j set up as Synology Hybrid RAID (SHR) with 2 2TB disks. What happens if the DS213j fails? Are the disks just mirrors so that I can connect either to a PC and see it as an external drive and recover the data? If not would it be better to change to RAID 1? What are the advantages of SHR over RAID 1?

SHR means Synology Hybrid RAID. The advantage of SHR is that SHR can better utilize capacity of mixed size disks, and SHR supports some weird disk upgrades which are normally done by deleting and rebuilding the traditional array.

However, if we are talking two identical disks and no plans to upgrade, SHR is in effect the same as RAID1, so there is really no choosing one or the other.

My Book World single disk

The most basic question about a WD NAS – How to recover data from a failed My Book World edition?

I have a 1TB My Book World … Logged in yesterday, just to reboot it (always figure its healthy to reboot devices/servers every few months). …  it says ‘drive not recognized’, and failed to mount drive. Updated firmware on unit, still the same… … taken HDD out the enclosure, and plugged it into my PC (Windows7).

Windows can see 5 partitions on the drive, as not NTFS/FAT32, i know it will format and lose the data the moment i try and add the drive….Any ideas on what software i can use to extract my data off the drive ???

Sure. Use Home NAS Recovery. This is not even expensive for a single disk.

For the record, it is not a good idea to reflash firmware on a bricked NAS. If something goes bad to worse, the newly flashed firmware may initiate some kind of initialization as the NAS may think the disks are blank. Side effects of initialization are never good.

Fixing an array with mdadm goes wrong

Now this is complex.

I have an mdadm-created RAID5 array consisting of 4 discs. One of the discs was dropping out, so I decided to replace it. Somehow, this went terribly wrong and I foolishly succeeded in marking two of the (wrong) drives as faulty, and then re-adding them as spare.

Now the array is (logically) no longer able to start:

mdadm: Not enough devices to start the array.

Degraded and can’t create RAID,auto stop RAID [md1]

As I don’t want to ruin the maybe small chance I have left to rescue my data…

This sure is complicated. Obviously, if you fail two array members, RAID5 goes down. Worse yet, once this happens, it stays down. You can’t tell it to accept the spares back in a normal way. Theoretically, some more fiddling with mdadm can force the array back into shape, but I doubt it is safe given a DIY environment. If your unit is still under warranty (this particular case was with Thecus), then by all means open a ticket and ask them to fix the issue – they are pretty good with mdadm. If the case is beyond Linux repair, fall back on our Home NAS Recovery – we are pretty good too.