Mass Storage Structure - Lecture Slides | COMP 310, Study notes of Operating Systems

Download Mass Storage Structure - Lecture Slides | COMP 310 and more Study notes Operating Systems in PDF only on Docsity! 1 COMP 310: Operating Systems Lecture 27: Mass Storage Structure November 29, 2004 Christine Alvarado Overview  Disk Management  RAID  Back-up storage 2 Review  What does the disk look like? Using the Disk  Formatting  Booting from disk  Dealing with Bad Blocks 5 Bad Blocks  Disks are flakey—some even come from factory with bad blocks  Handling bad blocks: Swap-Space Management  Swap-space size  Must be determined in advance  Better for overestimate size (Why?)  Swap-space location  2 options: 6 UNIX Swap Space management  Swap space allocated for text and data Redundant Arrays of Inexpensive (Independent) Disks (RAID)  Use many cheap disks instead of one disk to get better reliability and performance 7 Reliability via Redundancy  Mean time to failure—average time until a specific disk fails  Say mttf for a disk is 100,000 hours  If we have 100 disks… Solution: Redundancy