On Sun, 18 Mar 2007, Geoffrey S. Mendelson wrote:
Date: Sun, 18 Mar 2007 13:35:00 +0200
From: Geoffrey S. Mendelson <[EMAIL PROTECTED]>
To: Israel Linux Mailing list <[email protected]>
Subject: Rsync and databases
I lost the original to this thread, but I thought some comments may be
usefull.
First of all, rsyncing an open file is not a good idea. If the file
is a database you can end up with a totaly worthless bunch of random
bits. :-(
If the file is closed, then RSYNC will work, but it may not work for
all database systems, check before using.
Rsync will definately *not* work for Oracle database files. The rsync
fails on the verification stage. Use ftp instead.
- yba
If the record itself or the database has a creation/update timestamp
using it would be better. Run a job at an interval that dumps the records
using in restorable form to a flat file that have changed since the
last sync, and restore them to the copy of the database. This minimizes
the chance that either or both databases will get out of sync or become
corrupted.
Rsync will work perfectly fine for SAMBA mounts from Windows servers and
it also runs under SFU and CygWin directly on Windows. There may also be
a native Windows port.
Note that a little clever programing can create a "shadow" database using
a different access method. For example an SQL server accesed with ACCESS
on the windows machines and a MySQL or Postgess data base on a Linux
server. It would be best (if not required) to limit your updates to
one of them.
An example of this would be an order database that is filled and queried
on a web server and then shadowed on Windows machines for the bean counters.
Or the other way around, an exisiting Windows database can be shadowed
for web (or internal) browser access.
Geoff.
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