Data Recovery Forums - Help & Discussions

mrjoshuawells · Joined: 09 Sep 2009 Posts: 1

I am using Mac's OS X 10.5.7 and an ATTO Diamond Raid Array with 24 x 250 GB drives set to a level 0 Raid, then partitioned into 3 x 2 TB mounted drives.

Recently one of the drives in the array failed and after extensive testing, this one drive is toast. Since the drive was set p as Raid 0, this meant all the partitions were offline. I replaced the bad drive with a new one that was larger (400gb) then formated the entire array, once again to Raid 0, then partitioned into 3 LUN's. To my suprise, once I plugged it back in, the computer found my original 3 mounted drives, and the files all seemed to be intact. But then I went to Disk Utility to check the drives and the filesystem was missing or corrupt and the drive unmounted, and was unaccessable. I ran DiskWarrior on the drives and was able to rebuild the file struction with minimal loss of files.

My Problem is, the majority of data on this 6 TB array is video files, and now every mov file opens, but approximately every 3rd or 4th frame has large boxes of odd colors, you can see a frame grab here: http://www.babywildfilms.com/Bad_Frame_Img.jpg

The first question i have is whether a single partition of 3 partitions on a 24 drive raid level 0 uses space on all 24 drives evenly, or will each partition use 8 drives?

Second, has anybody seen this type of degradation on a video file before? It just seems too consistant to be simple corruption.

And lastly, are my partitions skewed because of the one larger drive? If I replace it with a 250 GB drive might that help?

I understand that there will be data lost, and I am not too concerned with that, as long as I can get back at the majority of my files.

vicky · Joined: 07 Mar 2007 Posts: 60

1- your partition will use the blocks on all of the 24 drives evenly
2- This degradation is due to loss of data blocks from one of the damaged disk which was in use in previous raid configuration, thats why you are looking a regular pattern in degradation
3- You partitions are not skewed due to 400 gb size of new disk, raid softwares are intelligent enough to manage the size issue.