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Carry Out Effective RAID 5 Recovery


I have a Windows 2003 server which I use along with a RAID 5 array containing 4 hard drives as part of a business working from home. I have recently been experiencing a problem on start-up which is preventing me from viewing the data which relates to my business. The error consists of one of my hard drives blinking a code to me, a code which consists of a yellow light and then a green light, blinking repeatedly. This new yellow and green light is rather obvious when looking at the server, particularly when all of the other hard drives have a regular green light, which is how I have always seen them before. The problem is that I am not able to see any of the data from the drives, even the ones which are still showing the green light. I have not yet tried to replace the hard drive with a new one, since I need to extract the data from the server first. Since I can’t see the data, I am going to assume that this message has something to do with a failure of the disk.


I need some help with an HP Netserver LH3 connected to a RAID 5 array. This is quite an old system, and has been sitting to one side of the computer desk for a long while, but has a lot of important company data on the drives. When I was away on holiday, someone took over the running of the servers, and did a little ‘tidying up’ while they were there, which means taking the drives out of the array, removing the sides of the enclosure, and blowing dust out of the server with a can of air. I work for the IT department of a textile mill, and I know that the air is full of dust. I also know that the server hadn’t been cleaned in a while, though the ‘someone’ insists that they dust the device regularly. Since this little Spring Clean, the array has refused to come online, and the server won’t boot. It is saying that there is no operating system found, the Operating System being one of the drives in the array. I have tried moving around the drives in the array, because they might not have been put back in the correct order, but the array is still not working. I have tried to rebuild the array using one of the disks, but this has not been successful.

Carry Out Effective RAID 5 Recovery

Computers and hard drive storage are almost ubiquitous within business in the modern world. Companies regularly utilise storage systems as their only repository of data and information, particularly for archived information. Although many businesses have a plan and procedure in place in event of the storage crashing and becoming corrupted there are many more that do not.

RAID disk drives are a very popular method for providing storage and in general are relatively resistant to corruption and damage, although RAID 0 systems are much more susceptible than later RAID configurations and architectures. The RAID 5 storage system utilises a striped with parity configuration. If a RAID 5 data storage system does stop responding and become either damaged or corrupt, there are two main options that are available.

The first is through a significant advantage that a RAID 5 data storage system provides. This is that the information is written across a number of drives along with additional parity data. Should one of the drives in the array fail the rest of the drives will operate as a striped volume but without parity and also without any associated loss of data. If the damaged drive is replaced with an equal, or higher capacity, drive the data on the damaged drive is reconstructed automatically on the new drive using the parity data that has been written onto the other drives. It is for this reason that at least three drives are used to establish a RAID 5 data storage system. On a degraded Raid 5 system sometimes when a disk is replaced the system only partially rebuilds. If this happens switch of your raid server and contact us for advice on how we can recover your data. Never attempt to rebuild several times or keep replacing disks in server hoping for it to rebuild. If it does not rebuild first time it won’t rebuild a 2nd, 3rd, or 4th time.

If the failure is not just limited to a single drive more extensive time and effort is required to recover the data. When several disks fail in a raid server self-recovery of the data is impossible, you will need to contact us for expert advice from a RAID 5 recovery specialist.

When we recover a Raid System we need to work out the basic information below. The first is the complexity of the RAID 5 array configuration. In order to begin the recovery of a RAID 5 system the following elements will need to be ascertained:

The number of disks that were in the RAID 5 array
What the sequence of those disks were
The size of blocks that were used in the array
The offset used before the array data begins
The parity pattern that was utilised
If delayed parity has been used the delay pattern will also need to be known
In some architectures there will also be spare blocks utilised and so the locations of these also need to be known

The second is the expertise that is required in order to maximise the amount of data that is recovered from damaged or corrupted disks. Our RAID 5 data recovery experts have access to specialist tools and software that they can use to ascertain all of the above information automatically. We have methods of creating images to work from so that the data on in original disks is not in danger of being further damaged in any way.