Stale Drive Detection for Windows NTFS Raids

Greetings and Salutations!

My name is Richard Correa and I am a Software Engineer and data recovery specialist for DTI Data. Over the years I have written many tools to help the technician resolve several of the problems they may encounter during their daily endeavor to recover a clients data. One of the most complicated, yet rewarding recovery situations is the RAID. Although somewhat simple in its design the implementation of the RAID, especially the RAID 5, has suffered many design upgrades to the point that it is virtually impossible to hand recover. I have written a set of tools to help me recover RAIDs and this tool, aptly named; the ‘Stale Member Detection’ tool has been priceless in its use.

Each RAID has its own unique set of problems to resolve, but finding a stale drive, until this particular tool, was one of the hardest to determine. For those who are new to RAID recovery let me illustrate the attributes of a stale drive by using the following real life example.

I receive several calls throughout the week that are RAID oriented. Approximately seventy percent of them concern a RAID 5. Of those calls I would estimate that forty percent of those have one drive down but the RAID is down. Yes that’s correct, one drive down, but the RAID 5 is down. RAID 5 by design will run with one drive down so why are the RAIDs not mounting? They are not running because they have a stale drive.

A stale drive, simply stated, is a drive that dropped out of the array, never removed, replaced, and rebuilt. It is allowed to remain in limited service until a second drive is lost as well. A stale drive normally does not have a bad physical problem. Something as innocuous as a slow read or write could cause the RAID firmware to degrade the RAID simply through a synchronization fault. If the RAID is shut down the stale drive may come back online and then embed itself back into the array. In addition during a self check the RAID controller may find a fault in the parity and try a rebuild to rectify the problem. Since the data on the stale drive is old, it will not only corrupt the stripe of the RAID, but the file system as well. This is particularly bad if the client has a large and active database.

All this being said, it behooves us to make sure that when a drive falls out of the array forcing a degraded state the drive is replaced and the RAID rebuilt. If such is not the case in your particular situation then by all means use the ‘Stale Member Detection’ tool to help find the offending drive so that you can replace and rebuild. As in all things make sure that a backup image is made of all the drives in the array before trying a rebuild, or reset, or initialization or whatever happens to be the industry catch phrase this week. It is infinitely better to be safe than unemployed.

Remember, there can be nothing more dangerous to your current employment status than a stale member.

We are offering the RAID Stale Member Detection software to our customers for the price of $9.99 Just click Buy Now to start using it today!