Issues that may arrive in moss 2007 while upgrading to sql server 2005 sp4

Hi,

We have a moss 2007 farm having clustered sql server 2005 sp2 for content databases. The servers for sql are Windows Server 2008 SP2 64-bit. Now we are planning to upgrade the SQL server 2005 SP2 to SP4.

Can someone please guide for:

- Any issues that may arrive while doing this upgrade?

- Any steps that we might have to take on MOSS 2007 before doing the upgrade. e.g. stoping any service etc.

thanks and regards,

kaushik