It is always a good idea to backup mysql database on a production server at regular intervals. Read my post how to auto schedule a mysql database-backup on windows or linux.
If you are using a RAID 0 drive for mysql and the disk failed to boot what will you do ? If you have mysqlbackup It is easy to reinstal mysql and restore database from backup . But what if you dont have any backup .. ?
Yeah it happend to me ! . I have used all the data recovery softwares i found on internet to get the databack . succeeded Only with TESTDISK and GetMydataback .
As soon as i noticed that my server is no more bootable due to RAID fail , I requetsed datacenter support team to keep the prsent RAID drive as secondary driver and add another harddisk and install OS on it .
I booted off serevr with newly installed OS but i can see the Failed RAID parition not mounted as it is showing RAW file system in diskmanagemnet.
I used TestDisk and tried to copy mysql InnoDB file idbdata1 from failed drive which is around 46 GB , but Test disk is copying the file in a kind of loop . Once The file being written completely it starts overwriting it again and again .