In this article we will look on the topic of handling a raid server recovery, A lot of people have been deceived that all RAIDs, especially RAID 1 and RAID 5 have built-in redundancy that prevents them from breaking down easily.
This erroneous belief prevents companies from doing proper backups. This misconception makes it disastrous when server failure occurs as a lot of data will be lost permanently.
Apart from interrupting their normal operation, they will need to manually enter a lot of records from paper documents and if the documents have been discarded, there will be a big problem.
The other problem is that, when this happens, non-specialists will begin to do some trial and error to revive the system and possibly recover some lost data.
They don’t realize that once there is an alteration of any disk in the array, there will be an increase in the magnitude of the problem and this often leads to permanent data loss.
So, it is necessary to offer some guidelines to follow so as to minimize loss of data.
Raid Server Recovery
Once you have a problem with your RAID server, you won’t be able to access the RAID volume anymore. When this happens, you have to bear in mind that recovering your data is not a task anybody can handle.
Only highly experienced system engineers can help out. However, being familiar with standard RAID configuration does not mean you have the skills and expertise to rescue a damaged or inaccessible RAID volume.
Data recovery is a totally different ball game.
There are no two ways about it. The only solution is to hire an expert. The tips outlined below are just to minimize data loss and also increase the chances of successful data recovery.
This is also important because a data recovery expert is not a magician. If you make things worse, he might not be able to retrieve lost data.
There are several disk failure or data loss scenarios. The commonest scenario has been discussed here.
The first and the commonest scenario is when there is one disk failure and your RAID server begins to run at degraded mode.
This is not a complete disk failure. It is a partial disk failure since the RAID will still be accessible in this state.
No data is lost yet. The problem here is that there is no more fault tolerance redundancy. It simply means your server cannot tolerate any more fault.
If another disk fails in addition to this, it becomes a total disk failure and the RAID volume becomes inaccessible.
When this happens, critical data should be backed up or copied out first before any attempt to rebuild it. This is because, when one disk fails, it brings others in the array closer to failure too.
Remember that disk failure is not such a big problem, but the data that may be lost with it is the real reason disk failure is a “dreaded monster”.
So, once critical data has been copied out, pressure and tense are gone. A standard rebuild process can then be launched. There will be no problem if other disks also fail in the process.
It is worthy of note that this is just one scenario. There are other more serious disk failure scenarios.