RAID has become an integral part of our computer world, especially on large servers where redundancy and efficiency is key. RAID has been developing and evolving for over 20 years, and today it is essential to most company’s IT needs.
With its ability to make things much more efficient, as well as provide the ability to mirror data to provide a backup, companies love it. However, as with anything, things can happen and failures can occur. RAID is not immune to that by any means.
In fact, there is a chance that your RAID array could fail at any moment. If that happens, then you need to start thinking about RAID data recovery.
Backup before RAID data recovery!
First of all, if you have data you care about, you should back it up!
Yes RAID provides a backup in a way, but you should never rely on that. You need to ensure you have a data backup of everything on that server so that when you do need to go through a digital data recovery of your RAID array, you are not as worried about losing data.
Remember, your RAID array may initialize and wipe all the data on the drives during a RAID 1 data recovery, and you don’t want that to happen. Backup everything as often as you can.
How do RAID failures happen?
We will just quickly mention how some of the most typical failures can happen.
- Hard disk fails with no hot standby, and as a result the RAID array begins to run in a degraded mode. The likelihood of a further failure of the RAID volume is very high at this point.
- A failure of the RAID controller.
- A power surge causes the RAID disks or the controller to fail, causing a corruption of the data.
- A faulty drive is used in an attempt to rebuild a RAID array.
Data Recovery of RAID Array
When you need to do a RAID data recovery, you can try the following steps:
- First thing you need to do is determine and secure the state of the current RAID array. Label everything so that after you have done the data recovery RAID 0 job, for example, you can get everything back the way it is supposed to be.
- Disconnect the array member disks and connect them all to a controller that can separate each one into their own individual drives.
- Launch recovery software to recover the array parameters. This is a very important step in any digital data recovery scenario.
- If you have software that allows you to build the array without initializing it, build the array in this mode using the recovery software parameters.
- If you are using a hardware RAID, mount the disk to the operating system you want to use.
- If you are using a software RAID, then during the RAID data recovery process, you should create an array image file, then use a data recovery tool to load it. If you can’t do that, then you need to load the parameters into the data recovery software, without creating an image.
- Once you have all the data saved properly and checked, you can begin to rebuild the original RAID and you can start to copy the data back. This is the last step in any sort of RAID data recovery.
It is very important to note that you must be careful when doing any of this. If you try to rebuild any RAID configuration in the wrong order, chances are you are going to lose all your data. The controller is going to initialize the array and when that happens, all the arrays will be initialized with zeroes. This in turn will erase all your data and your RAID data recovery attempt fails.