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[Xen-users] How (not) to destroy a PostgreSQL db in domU on powerfail

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Subject: [Xen-users] How (not) to destroy a PostgreSQL db in domU on powerfail
From: Michael Monnerie <michael.monnerie@xxxxxxxxxxxxxxxxxxx>
Date: Tue, 24 Feb 2009 10:20:54 +0100
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Now I'm sure that the following configuration can destroy a PostgreSQL 
8.3.5 database:

* Linux host (dom0) with XEN, XFS filesystem with "nobarrier", RAID 
controller with battery backed cache.
* XEN vm (domU) with XFS filesystem with "nobarrier" with postgresql
* my daughter with 3.5 years switching off the power supply of the 
server, just behind the UPS

Seems XEN does lie about fsync, otherwise it shouldn't have crashed the 
database (so badly that I could not even dump it, had to restore).

Is there a way to secure domU's in a way they survive a powerfail?

mfg zmi
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