Durability (cont)
Durabilty begins with a stable disk storage subsystem.
i.e. effects of putPage() and getPage() are consistent
We can prevent/minimise loss/corruption of data due to:
- mem/disk transfer corruption: parity checking
- sector failure: mark "bad" blocks
- disk failure: RAID (levels 4,5,6)
- destruction of computer system: off-site backups
|