Hard drive failure, dynamic disk

[mirhagk]

Hello everyone, so my hard drive decided to die yesterday. It made me sad. The thing is is that I have 2 hard drives in my computer and actually the one hard drive didn't completely die, it just has a bad sector (which means I can probably partition it such that that sector is avoided). I got some recovery discs, I backed up both hard drives, and I installed Kubuntu on an external hard drive so I could test the rest of the computer. I even downloaded a dev preview of windows 8 to install (might as well take the oppurtunity to try it out).

However I have a huge issue. The two drives were partioned as follows:

Disc 1:
Partition 1, C:\ (OS) Partition 2: Half of a RAID-0 configuration

Disc 2:
Partition 1, E:\ (data) Partition 2: Other half of RAID-0 configuration

The RAID's are set up with windows dynamic discs, which are causing all the problems. Basically no other tool is able to read it, and even my mini bootable versions of windows are XP home edition and therefore unable to deal with it. I tried installing windows 8, hoping it would give me the option to just format the entire hard drive, but it doesn't like dynamic discs.

I don't care about keeping my partitions (in fact I now hate that RAID configuration, possibly might switch to RAID-1 but not sure yet), so how can I format the entire hard drive if they are dynamic discs that most OS's can't even detect (Kubuntu did detect them and let me copies files over, but they only detected the first partition on each)

[DemonWasp]

Generally, you should be able to just "delete partition table" (that'll delete all record of where partitions are, which seems to be what you want). Then you can create a new partition table that suits your new needs (and new partitions, each of which you format independently).

You generally don't format a whole disk. If you must, something like this works to wipe sda:

code:

dd if=/dev/zero of=/dev/sda bs=4k

Obviously, that's a pretty dangerous command. It shouldn't work against mounted devices (use umount to unmount auto-mounted partitions) but I'm not about to test that. Type carefully!

[mirhagk]

Thanks demonwasp, fortunately I was able to do without. Kubuntu is apparently either to stupid or arrogant to even know that it was a dynamic disc, and just saw it as an unrecognized partition. I simply ran the installer over both drives, telling kubuntu to use everything, so it erased evidence that it was a dynamic disc, and then installed windows 8(which boots in like 2 seconds on my machine, compared to 7's 5-10 seconds).

Now I just need to find the errorneous parts on my hard drive, and format the disc around it, any ideas?

[md]

Repeatedly write to the drive until it fails. Replace under warranty. Use smartmontools with linux in order to tell if the drive has actually failed.

Modern drives remap blocks which fail (and modern drives work in terms of blocks, not sectors/cylinders though sometimes a block is referred to as a sector... terminology sucks). If you're lucky it's a single failure and you should be fine to use the drive without any special action on your part. If your unlucky there are lots of remapped blocks and more are failing all the time. If that's the case you're gonna have to replace the drive.

Smartctl will tell you all that and more.

[DemonWasp]

It's not so much that Kubuntu is stupid or arrogant: it's (probably) that Microsoft couldn't be arsed to release details of their Windows-only RAID implementation. If they did, I would expect that it would eventually get implemented on Linux. Since they haven't, it would be incredibly difficult / dangerous to mount such a partition, since you could easily break it. Far better to remain uninvolved in that case.

[mirhagk]

I didn't mean it as in Kubuntu was bad, I meant it more as Kubuntu probably saw MS's implementation (and the whole idea of software RAID) as stupid, and chose not to implement it. And MS probably did release details somewhere, they've been really good about that lately (considering the fact they were sued because they didn't give OS's out to competitors before they released them). Nowadays pretty much every MS product has a dev preview, and they are 100% free, and are usually cracked and known before the product is released.

[DemonWasp]

I haven't been able to find Microsoft's documentation of how this feature works (disk storage formats, information, etc), but maybe it exists. If it does, please link me to it -- I'd like to know how it works. Come to think of it, it is possible (if unlikely) that they used something standard that could have been detected with dmraid ( http://manpages.ubuntu.com/manpages/natty/man8/dmraid.8.html ):

code:

dmraid -r

Kubuntu, like nearly all Linux distributions, supports software RAID out of the box -- you can even set it up in their installer ( https://help.ubuntu.com/community/Installation/SoftwareRAID ). I should know: I'm running one right now on my server machine. It was painless to set up, trivial to use, and if the machine (software or hardware) ever dies, I know I can revive it from a LiveCD. This scenario you're encountering now is exactly why I chose hardware fake-RAID for my Windows box: recovery after your install dies can be difficult.

[mirhagk]

Yeah unfortunately your never gonna convince me to switch from windows, there's too many personal reasons to stay with it (among them is gaming, programming[.NET, and XNA] and so that I can be sure all my programs work)

I think I am going to go with RAID-1, that way I can be sure I don't lose files.

Also I noticed that many of my files being downloaded suddenly failed to write to disk, but after resuming they are fine, so there is an issue with the hard drive, but fortunately windows 8 handles it better than 7