[OpenAFS] About `dafileserver` vs `fileserver` differences (for small cells)

Ciprian Dorin Craciun ciprian.craciun@gmail.com
Sat, 9 Mar 2019 08:50:40 +0200

On Sat, Mar 9, 2019 at 4:10 AM Mark Vitale <mvitale@sinenomine.net> wrote:
> DAFS main benefit is the reduced impact of restarting a fileserver, especially
> fileserver with thousands or even millions of volumes.  DAFS fileservers
> are able to restart more quickly, are able to avoid restarts formerly required for
> volume salvages, and are able to reduce the negative effects of restarts on clients.
> Here are some details about how these benefits are acheived:

Thanks Mark for explaining the advantages of DAFS, especially number
(4) (i.e. saving of the client "states").

However is it still "safe" and "advised" (outside of these
disadvantages) to run the old `fileserver` component?

(More specifically, from a source code point of view, outside of the
demand-attach, are there any other performance / stability
improvements in DAFS as compared with FS?)

BTW, on the topic of volume salvaging, when I define my DAFS / FS node
I start a node of `salvager` (for FS) and `dasalvager` and
`salvageserver`.  However looking at the running processes the
`salvager` and `dasalvager` don't seem to be running after the initial
startup.  Thus I wonder how the salvage process actually happens?

Does the `fileserver` / `dafileserver` actually start the salvage
process, or do they communicate this to the `bos` to restart only that

(My main reason to ask this, is in anticipation of my other email
which tries to identify if I can safely run the fileserver processes
directly from `systemd` outside the control of `bos`?)