Some quick highlights from our Gluster talks at LinuxCon EU, as well as slides available as a PDF below.
Bitrot detection in GlusterFS – Gaurav Garg, Venky Shankar
BitRot detection is a technique used to identify certain “insidious”
type of disk errors where data is silently corrupted with no
indication from the disk to the storage software layer that an error
has occurred. This class of data corruption are very different than
latent sector error typically caused by damaged disk drive. When data
gets “rotted”, an application can still access data off the disk drive
unknowing that the data is corrupted.
With GlusterFS 3.7, its possible to detect corruption caused due to
bitrot and take steps to rectify them. When bitrot detection is
enabled on a Gluster volume, files are signed after they have been
written. A periodic filesystem scrubber verifies the integrity of
signed files are flags (or marks) files which have mismatching
signature. Corrupted files are typically denied access to clients
unless it’s a replicated volume where it’s still possible to access
the “good” copy and repair the corrupted file.