RAID 5 Faliour, 1/2 of the data Lost data during RAID rebuilding

[GIKUYU]

Hi, i am hopping this is as fascinating as is to me.

i have a RAID 5 DELL Power edge 6800 SERVER with 3 drives each 300gb making a volume of about 600gb. split into two partitions C: About 20gb" with windows" d: about 500gb " with data and active databases" with almost 400gb of data

i am consulting for the company and this is the information i have in regards to its faliour.

the server RAID filled a few weeks back and the RAID wouldn't rebuild, they called in a Dell consultant who helped them rebuild the RAID.

on the RAID rebuilding the boot partition c; refused to boot so they formatted it and put in a new Windows installation, on booting the windows they realized the d; partition had rebuild but only half of the data previously there is available i.e about 178gb of data is only available the rest is not there.

is there any explanation as to how this may happen
if the rebuilding was done OK, and maybe during the re installation they Run a chkdisk on the volume d; would this cause the loss of data

some of the traces of the missing data being found is mostly data with 0mb in size

there are critical databases missing on the server running on sql 2000, is there a tool to curve our or run a RAW recovery for SQL.

we have run all possible tools r-studio, get data back, data recovery wizard and none of this tools can get the lost data

what explanation exists on this case

how do i get the lost data?

is there a way i could get the windows log files/ event viewer to know what transpired before the faliour, who logged on to the system etc

[GDH]

Hi,

If you have a RAID failure and you are reading this post, the FIRST thing to do is to take a sector copy image of each disk.

If it very easy to screw up a raid recovery and a sector copy of each drive will mean that no matter what you do, you cant make things worse, because you can always restore the sector copy to the physical drive and go back to square one.

RAID 5 is a striped set with distributed parity. This means that for speed purposes, a single file can be split on 2 separate physical hard drives (with the third hard drive providing redundancy).

I no longer think it will be possible to rebuild the raid - the re-installation of Windows and the subsequent partition size error suggests that any of the old RAID array records will now be completely screwed up.

The only thing I can suggest is that you try running a "Complete File Search" with Recover My Files on the physical drives for specific file types. You are likely to find only files that are small enough not to have been split over the two drives - but this may be better than nothing.

Good luck.

[GIKUYU]

i have used that option on the entire volume but the only sql files i get they are below 1 gb ie about 1024 mb where as the databases are about 14gb and 4gb how comes it cant even get some existing databases on the server at the moment

[GDH]

Try the search again, but first this time click on the OPTIONS button and under the SEARCH tab take the tick out of "try and determine file size" and set the default file size to the size of your missing file.

However, this method of recovery locates the file header and the progresses the required distance down the disk to locate the file. Therefore, if the file is fragmented, the result is likely to be corrupt.