[tahoe-dev] Share rebalancing

[Shawn Willden]

I noticed this morning that for the last couple of days my "backups" have been 
going nowhere.

I have a small friendnet, and for some reason all of the other nodes went down 
at roughly the same time.  My backups continued chugging away, but the only 
storage node available was my local node -- so all shares went there.  Not 
very useful.

I'm going to set up some monitoring stuff to notify me and automatically shut 
down the backups whenever grid health drops below an acceptable level, but my 
first concern is to figure out how to fix the useless backups, to distribute 
the shares properly.

I'm looking for ideas about how I can do this.

The best plan I've come up with so far is this:

1.  Modify GridVerify (my backup checker, which walks the backup logs and 
checks the health of each file using the check function of Tahoe's web API) 
to evaluate the share allocation of each file and log the readcaps and 
storage IDs of those that aren't spread across enough servers.

2.  Write a script to retrieve each of those readcaps.

3.  Write a script to delete the local shares by deleting the storage ID 
directories.

4.  Re-upload the downloaded files.

Any other ideas?

	Shawn.