Autosave doesn't have a coded limit on the number of files it's handling. Bob Dalesio's original code
used a linked list, and that's how it still works. I haven't tested large numbers of files, but in some ways
splitting an autosave file into several smaller ones would improve the overall efficiency by decreasing
the number of unchanged PVs that are written when one PV changes.
Autosave has only eight sets of status PVs, but the only consequence of going over that limit is that
a file's status will not be available via PVs.
You can run only a single instance of autosave in an IOC, because two instances would run into
There is another possibility: If you make a single autosave request file from many individual files, using
the include-file mechanism, you have most of what is needed to later split off an application to a different
IOC. You could copy the full save file to the new IOC and just put up with the error messages the first
time autosave tries to restore PVs that don't exist in the IOC. Boot-time restore is strictly limited to the
ioc in which it runs. (However, manual restore does not limit itself to the ioc in which it runs.)
From: "Emmanuel Mayssat" <email@example.com>
To: firstname.lastname@example.org, "emmanuel mayssat" <email@example.com>
Sent: Thursday, April 11, 2013 6:43:32 PM
Subject: autosave limitation?
I have several device running in a master IOC.
I would like to use autosave.
The issues is that I would like to break down my master IOC into smaller ones at will (for development purpose).
I would like to use several req files and restore files for autosave.
In other words, I would like to have one autosave configuration per device in the master IOC.
Q: Is there a limitation to the number of files and instance of autosave in a single IOC?