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Bad Sectors

Posted: Wed Jun 15, 2011 9:01 pm
by Guest
In creating an image of a 1tb hard drive that is drive #5 in a raid 5 arrray it begins producing read errors at 80% done. Every eight seconds it attempts to read the next position and fails. This has been going on for seven days now. At this rate I have calculated the image will be completed in about a year and a half. I know the last 20% of the hard drive is bad so how would I go about creating an image of the drive with the first 80% of the drive reading fine and the last 20% bad. I am fine with an image that has 80% of the data and the last 20% zeroed out.

Is there a way to only image 80% and then have r-studio just write zeroes to the remaining 20% of the image?

The reason I am doing this is for some reason the original drive #5 is the only one that wants to rebuild the array, but due to the errors the rebuild fails. Initializing a new drive and putting it in slot 5 puts the raid offline. So I need to image the drive #5 and put the image on a new drive so I can rebuild the array.


Re: Bad Sectors

Posted: Thu Jun 16, 2011 3:20 am
by Alt
You may create a region of that size (80%) and create the image of that region. Then you may create a RAID using that region as a disk or copy that region to another hard drive to rebuild the hardware RAID. See more about regions at R-Studio help: Regions.

Re: Bad Sectors

Posted: Thu Jun 16, 2011 11:52 pm
by Guest
Thank you for the information. I made a 50gb region on the first 50gb of the bad 1tb drive and then imaged it. I then copied the image to the new drive which made a 50gb partition with the remainder unallocated. Thinking that the raid information should be in that first 50gb I put the new drive in the array. At bootup the raid still found the new drive as legacy and the array was disabled and drive 5 (the new drive) was offline. All the other drives in the array come up as configured. I went ahead and initialized the new drive but the array still comes up as disabled with the drive offline.

Putting in the old drive shows all drives configured and the rebuild starts, however, due to the errors the rebuild fails.

I am using eight 1tb drives in this raid 5 array. Only drive 5 has failed but putting in a new drive but even after initializing the raid stays offline and doesn't begin the rebuild.

It is a hardware raid with the rocketraid 2322 controller running on windows server 2003.

question : How best would I copy the configuration data of the raid from the old damaged drive to the new drive so the raid will recognize it as part of the array, just as it does the old damaged drive, and then begin the rebuild with the new drive installed? Recall that the raid rebuilds with the old drive in until it encounters the errors on the old drive after a few hours and then the rebuild fails. Is the configuration data in a place that r-tools does not image?

Re: Bad Sectors

Posted: Fri Jun 17, 2011 10:11 am
by Alt
Most likely your RAID controller stores some its configuration data at the end of its disks. Thus when you create a region on the faulty disk, it appears behind the region area, so it's not copied. But it's on healthy sectors and the RAID controller can read it. So, my recommendation are the following:
1. The most reliable solution: create a virtual RAID from the healthy disks and the image of the region. Copy the data from the virtual RAID to some temporary storage. Create a new RAID replacing the faulty drive and copy data back to the RAID. If it's crucial to have an exact copy of the volume written on the RAID, you may create an image of the volume on the virtual RAID and then copy that image to the new RAID. Drawback: you'll need a temporary storage place for the RAID data.
2. If you don't have such a place: you may try to locate where the bad sectors end and create an exclusive region, cutting off the bad area. Then you may create an image of that exclusive region and then copy it to another hard drive,or copy the exclusive region directly (without creating the image). The bad area will be filled with the characters specified on the Bad Sectors tab of the R-Studio Settings panel. Then you may rebuild the RAID.