[Zope] Backing up the Data.fs

[Paul Winkler]

On Mon, Nov 05, 2001 at 05:18:19PM +0100, Alastair Burt wrote:
> Footnotes: 
> [1]  I think my scripts to automatically start up Zope in event of a crash
> may have led to two instances of Zope trying to serve the same Data.fs.   

Zope exits on startup if it can't lock the database. 
The code that handles this is in lib/python/ZODB/lock_file.py.

Having looked at it, I must say it doesn't exactly make me feel
safe. Looks like it should work on unix and windows, but if it
should fail to define a working lock_file function it silently defines
lock_file as a no-op. Is it just me, or is this dangerous?

It does seem to work properly on linux at least. Example:

[pw@roaddog Zope]$ ./start &
[1] 6959
[pw@roaddog Zope]$ ./start &
[2] 6964
[pw@roaddog Zope]$ 
[2]+  Done                    ./start

A look at my log file shows this:
2001-11-05T16:26:58 PANIC(300) z2 Startup exception
Traceback (innermost last):
  (snip)
StorageSystemError: Could not lock the database file.  There must be
another process that has opened the file.


-- 

paul winkler
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