Can I move drives from a failed NAS?

[psx_999]

Hi, I have just bought a Thecus 3200PRO and set it up with 2 * 1.5TB using RAID 1. For lnowledge purpose, I would like to inquire, in the event that the NAS unit itself fails, can I just un-plug my hard disks an plug them into another new NAS and it will run as per normal with all my files intact? Thanks.

 

[Guy Incognito]

I have this same question. When learning about RAID, they always talk about what happens if a drive fails - but they never talk about what happens if the storage device itself fails.

This excerpt from the Wikipedia article on RAID even makes it murkier:

Equipment compatibility

The disk formats on different RAID controllers are not necessarily compatible, so that it may not be possible to read a RAID on different hardware. Consequently a non-disk hardware failure may require using identical hardware, or a data backup, to recover the data. Software RAID however, such as implemented in the Linux kernel, alleviates this concern, as the setup is not hardware dependent, but runs on ordinary disk controllers. Additionally, Software RAID1 disks (and some hardware RAID1 disks, for example Silicon Image 5744) can be read like normal disks, so no RAID system is required to retrieve the data. Data recovery firms typically have a very hard time recovering data from RAID drives, with the exception of RAID1 drives with conventional data structure.

I'm not that experienced with this, but when I think of software RAID, I'm thinking about how Windows NT/2000 Server did software RAID [which I don't recall anyone ever actually doing this].

I assume with the RAID 1 device I can just take one or both drives and put them in another RAID 1 device as long as the new device can read the same file format NTFS, FAT32, EXT, etc. I could even throw one of the drives in an external hard drive case lying around. This is because there is no parity information involved.

But what about the RAID 5 disks? Can I just take the disks and put them into another RAID 5 device made by another company? I assume I just couldn't take one of the hard drives and throw it in an external hard drive case because a file could be spread across all the disks and I would need data from all the disks. Is the information written on RAID 5 disks can only be seen by that particular storage device itself?

 

[claykin]

Hi, I have just bought a Thecus 3200PRO and set it up with 2 * 1.5TB using RAID 1. For lnowledge purpose, I would like to inquire, in the event that the NAS unit itself fails, can I just un-plug my hard disks an plug them into another new NAS and it will run as per normal with all my files intact? Thanks.

In general the answer is NO. At least you want to treat it like a NO until you know for sure.

1) If you were to replace the disks into another 3200Pro with the same firmware rev, then you should be fine. Its sometimes important to install the disks in the same order they came out of the old unit (disk 1=disk1). Make sense?

2) If you are migrating to a new NAS, I would use an abundance of caution before installing the disks int the new unit, even of the new NAS is Thecus. Most NAS products will want to reformat the disks very quickly after detecting disks that don't belong there.

So, I would highly recommend you backup your NAS data to another destination.

In some cases a RAID set can be read on a PC. It will usually require the use of Linux. Some Linux Live CD's will be able to read the RAID set so you can extract data from it. Don't rely on this, its for emergency purposes only. backup your important NAS data. RAID is not backup.

 

[johnnyr]

Mirrored drives

Since the drives are mirrored, you can remove both drives from the new unit and install only one of the old drives. The NAS should recognize the drive and operate with it. Failure to do so should not affect the data on the drive, but just in case you still have the other side of the mirror.

If the drive is recognized and useable, insert one of the (blank) new drives and let the system rebuild the mirror.

The only way I can see a problem developing is if the system builder went out of his way to lock you in some how. This seems common in the software world but isn't expected with hardware, fwiw.

 

[gospeed.racer]

This is cool, I got an answer to a question I hadnt even really considered. What IF the NAS itself fails, not the drive...That sounds kinda scary. The whole idea behind what I am trying to accomplish is keeping my data safe, hadnt really considered anything but loosing a drive or 2 up till now.

Now I am a bit scared, is there a type of raid that is "more" compatible or more easily read by Linux? (for MY purposes I can have either 5 or 10). It sounds to me like 10 is safer, but I am VERY new to all this!

 

[johnnyr]

RAID types

Hi Goracer,

You could start here to get a good overview of the different types of RAID.

http://en.wikipedia.org/wiki/RAID

Then you can ask any questions here is something isn't clear to you.

 

[gospeed.racer]

Thank you for your comment, but I have read of the different types of Raid. I know the general way it works, and had settled on Raid 5 to get a bit more miles out of my TB's over raid 10. Then as I read more about 5, I decided to use 10 as it seems far safer and can suffer multiple drive failures. So I am pretty much at a crossroads.

What your link doesnt tell me is what I was asking- is one easier to recover than the other? I dont mean recover from drive failure, I mean NAS failure. I dont care if I need to pop a new drive in it once in a while, its when the box fails that I will be up a creek. It sounds like raid 10 data can be recovered with raid 0 tools. For this reason, as well as speed and safety, I will go with raid 10.

Thank you for your time.

 

[johnnyr]

Sorry I misunderstood your question

In my opinion, if the box fails, you better have a backup somewhere. Getting a new controller to recognize the previous RAID configuration is beyond my skill level!