The client in this data recovery case came to us to get data recovered from their crashed Dell T420 server. This Dell T420 server used a RAID-5 configuration. It had eight two-terabyte Seagate hard drives for a combined total of 14 terabytes of storage space. This was plenty of space to store their SQL database, as well as their other assorted files. And with RAID-5’s single-disk fault tolerance, their data was well-protected.
But, as we’ve discussed quite a few times on the Gillware blog, RAID fault tolerance on its own isn’t always enough to protect your data from disaster. And, unfortunately, it wasn’t enough here. After the Dell T420 server crashed, our client-to-be took a look at it. BIOS troubleshooting dialogues showed two culprits for the server failure. Six of the eight hard drives were online, as they should have been. But the two remaining hard drives had crashed. One came with the error message, “State Failed”. The other came with the error message, “State Foreign”.
With two hard drives down, the RAID-5 server’s XOR parity-based fault tolerance couldn’t plug up all of the holes in the server’s logical volume, causing a fatal server crash. To get their data back and their small business up and running, the owner called upon the server data recovery experts here at Gillware.