Block Checksum
Assuring data integrity
NetApp uses an advanced method of ensuring consistency of data written to the disks. Perhaps the easiest way to think of this is “in-line RAID”. For every 8 data blocks, each of 512 bytes, the 9th block contains checksum information about the preceding 8 data blocks. The checksum information is read in the same I/O request so there is no performance hit. The checksum information is compared to what was expected and if they do not match then the bad block can be immediately reconstructed from the other drives. With RAID-DP this can even be done if a disk has failed or is missing!
Monitoring block checksums can be used to ensure the continuous integrity of the data on the disk. If multiple inconsistencies are detected then Data ONTAP StoreVault Edition can initiate a Rapid RAID Rebuild in the background, if there is a hot spare in the system This avoids the need to fail a drive outright and go through the performance hit of a regular rebuild.
Block checksum is part of the Advanced Protection Architecture and is just one of the ways that StoreVault delivers peace-of-mind data protection, allowing you to spend more time on growing your business and less time worrying about your growing storage. [more »]
