[Tinyos-Storage WG] TinyOS Mailing List

[Prabal Dutta]

I think everyone who has been involved in the storage WG formation
e-mails and inaugural conference call has now signed up on the list.
Now that everyone's on board, let's switch to using the list so we
automatically archive e-mails.

Summarizing for posterity on the mailing list some useful information:

********************************************************************************

KICKOFF E-MAIL [Deepak Ganesan]

Folks,

Here is a starting point for the agenda for the Storage WG. We need
to generate a brief one-page proposal in about 10 days, and then
start discussing regularly to make progress.

Here is a draft outline of the charter and the main goals of the WG.
Feel free to add or update the outline. Would like to have an initial
round of comments by email so that we can send out the 1-page
proposal. After that time, we can try to schedule a weekly meeting
time to discuss the WG.

Charter: To define storage interfaces and abstractions, reusable non-
volatile data structures, interoperability requirements for
components that share flash memory, and reference implementations of
storage systems.

Below are the key issues in a little more detail:

+ Sharing storage between different applications/objects
       - Split storage into volumes and let each application handle its
volume however it wants:
               + Volumes: TEP 103 describes an approach for dividing the flash
into volumes between different applications
               + Interface VolumeSettings (Blackbook): get information about
volume size, read/write units, erase size, etc.
       - Interleave objects within a single volume:
               + Object: Capsule describes an approach for
interleaving different
objects in a single log.

+ Re-usable non-volatile  data structures/objects:
       - Files:
       - TEP 103: Large "write once" object, Logs, SmallObject
       - Database objects: BDictionary (Blackbook), Stream, Index, Queue
(Capsule),

+ Support for checkpointing and rollback (for hibernation or recovery
from node failure)

Timeline:

- Feb/March/April: Discuss and finalize interfaces
       + the goal here would be to decide on the abstractions for sharing
storage, data structures and support for checkpointing/rollback
- May/June/July: Reference implementation
       + would be good to have two or more reference implementations that
port the systems that we have already built to the interfaces that we
decide to use
- July/Aug/Sept: Performance evaluation


References (alphabetical):  feel free to add to the list

Blackbook File System
http://mail.millennium.berkeley.edu/pipermail/tinyos-devel/2006-
November/001516.html

Capsule: Object Storage System
http://sensors.cs.umass.edu/projects/capsule/

ELF: Log structured Flash file system
http://mantis.cs.colorado.edu/media/sensys_elf_external.pdf

FlashDB:
http://research.microsoft.com/research/pubs/view.aspx?tr_id=1214

Matchbox:
http://www.tinyos.net/tinyos-1.x/doc/matchbox.pdf

Microhash: Efficient index structure for flash memory
http://www.cs.ucr.edu/~vana/microhash.pdf

TEP 103:
http://www.tinyos.net/tinyos-2.x/doc/html/tep103.html

TINX: Tiny Index
http://graphics.stanford.edu/projects/lgl/papers/mrl-tinx-06/mrl-
tinx-06.pdf

********************************************************************************

CAPSULE [Gaurav Mathur]

tinyos-1.x/contrib/umass/tos/interfaces:

http://tinyos.cvs.sourceforge.net/tinyos/tinyos-1.x/contrib/umass/tos/interfaces/

********************************************************************************

DIRECT STORAGE / VOLUME SETTING [David Moss]

tinyos-2.x-contribs/rincon/tos/chips/stm25p
tinyos-2.x-contribs/rincon/tos/chips/atm128/flash
tinyos-2.x-contribs/rincon/tos/interfaces

********************************************************************************

- Prabal