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Debian Squeeze KVM server with Win2k8 server guest. The server has 16GBs of RAM and the guest only runs MS SQL, with a 15GB database on it. I am wondering if there is anything I can tune from the default memory or storage settings in either the Kernel or default Debian settings that might aid performance here.

Ideally on the Windows guest I am going to have to find a way of making the MS-SQL server keep as much of that DB as it can in RAM so this will hopefully translate directly into physical host RAM. The DB is for a voting system so its a mix of write for votes and reads for daily results and reports. Is there anything I can tune about the host FS perhaps like swapiness or dirty_ratio that would be beneficial here?

I don't know MS-SQL very well, I would assume I can't tune how write are handled. I assume that even if the DB is in RAM, DB writes in Windows are flushed to disk strait away on the guest, so this will pass down to the host. The host runs DRBD and replicates the guest VM live to another server. Anything I need to be aware of here perhaps?

Many thanks.

user@machine:~$ kvm -version
QEMU PC emulator version 0.12.5 (qemu-kvm-0.12.5), Copyright (c) 2003-2008 Fabrice Bellard
user@machine:~$ uname -a
Linux myhost 3.4.9 #1 SMP Wed Aug 22 19:08:46 BST 2012 x86_64 GNU/Linux
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