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	id AA08896; Thu, 7 May 92 16:58:46 -0700
Message-Id: <9205072358.AA08896@postgres.Berkeley.EDU>
From: postarch (Postgres Mailing Archive)
Subject: Re: vacuum
To: postgres@postgres.berkeley.edu
Sender: pg_adm@postgres.berkeley.edu
Reply-To: mer@postgres.berkeley.edu
In-Reply-To: Your message of "Tue, 05 May 92 12:02:55 PDT."
             <9205051845.AA03160@dpi.inpe.br> 
Date: Thu, 07 May 92 16:53:06 PDT

you write:
> I am trying to vacuum (v3r1) a database and I am quite sure I have no other vacuum cleaner running. Why do I receive this message?
> 
> Query sent to backend is "vacuum "
> WARN:May  5 16:37:57:can't create lock file -- another vacuum cleaner running
 +?
> 
> Can someone tell me more about the vacuum cleaner?

In order to guarantee that there is only one vacuum cleaner command running
at a time the backend creates a file "pg_vlock" in the database directory.

If this file already exists the current vacuum command aborts assuming that
another vacuum is currently being run.  If a vacuum command caused a crash
it is entirely possible that the pg_vlock file was not removed.  If you are
sure there is no vacuum running you should remove the pg_vlock file by hand.


Jeff Meredith
mer@postgres.berkeley.edu