Storage System Requirements

• Look like a filesystem
• Dynamically increase redundancy
• Dynamically increase capacity
• Utilize variably sized disks
• Support migrating onto larger disks (i.e. replace a 250GB drive with a 500GB drive)
• Removal of drives for offline redundancy
• Distributed space sharing with partially trusted parties
• Snapshots
• Mount historical/point in time view
• Compact small files/partial end blocks based on how static they are?
• Migrate static data to more compute intensive/compact redundancy representations?
• Configure a full copy of files to be contained within a defined border
• Concurrency
• ACLs

Niceties

• Operating system lives independently of disks (flash or cd+flash)
• limited caching/synching for laptops that disconnect from the network
  • Possibly per directory
  • Dont cache large items that are intended to be streamed (many media files)
• Built in support for managing backups to/restores from alternate media (likely DVDs)
• A cheap copy operator. Help to restore previous versions to a writable state, or to have a sort of branching maybe.

Possibly Helpful Research

• http://en.wikipedia.org/wiki/List_of_file_systems
• ZFS
  • http://www.sun.com/software/solaris/zfs_learning_center.jsp
  • http://www.sun.com/2004-0914/feature/
  • http://en.wikipedia.org/wiki/ZFS
  • http://www.linux.com/articles/51237
• Par
  • http://www.cs.utk.edu/plank/plank/papers/CS-96-332.html
• RAID
  • MD (linux raid driver 'multi-device') + event numbers
• GFS
  • http://www.google.com/url?sa=t&ct=res&cd=2&url=http%3A%2F%2Flabs.google.com%2Fpapers%2Fgfs-sosp2003.pdf&ei=9jsKSPOhJJHiggLR963sDQ&usg=AFQjCNHCcMYVzxld481n3XFz9k2x38OlZw&sig2=u4ISsEYsOyNtCW0nPU3jVw

Use Cases

• Photo/Home movie storage
• Backup solution
• Store my tax files without fear of losing them, ever
• mp3/xvid collections
• nfs mounted home directories
• email boxes

How to test fs for general correctness and correctness under various failure conditions?

IDEA: Distribution nodes. for distributed fs. Define logical structure of desired redundancy. Disc->Machine->Site->Region->Continent->Planet->SolarSystem... Redundancy level would be some function of what the highest level it was a member of multiple nodes. if it is on 2 discs on 1 machine, that is a smaller redundancy than if it is on 2 discs from 2 different sites.

Steps:

1. Filesystem/FUSE symantics
2. Redundancy across drives
3. Redundancy across servers