[cap-talk] E persistence & MinorFs private storage

Rob Meijer capibara at xs4all.nl
Sun Jul 20 08:17:40 CDT 2008

I don't believe I completely seem to be able to grasp E persistence from
what the Persistent eChat example demonstrates.

>From what I think I understand, I've now put the following text on the
MinorFs wiki at
http://minorfs.polacanthus.net/index.php?title=MinorFs_and_E :

Note: the text below is currently unvalidated !

MinorFs provides private storage to pseudo persistent processes. The E
language is an object capability language that provides persistent VATs.
Given that a persistent VAT is tied to a file on disk, having the file on
disk made private to the pseudo persistent process by storing it under the
/mnt/minorfs/priv/home directory should help persistent E VATs in keeping
their state and capabilities protected at the OS process level of

An other concern with E ar the OS process level of granularity might be
leakage of authority through the trace files that E creates. It might be a
good option to set the "TraceLog_dir" option in /usr/local/e/eprops.txt to
/mnt/minorfs/priv/home if leakage of authority by means of the tracelog
might constitute a concern.

Given my currently still limited understanding of persistence in E, the
abouve might be completely based on my misconceptions.

Anyone with a good understanding of E persistence, please feel free to
edit the wiki page, and possibly add a simple example.


Rob J Meijer

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