The explanation offered doesn't make much sense to me.
"tempdb is reallocated every time the instance starts. This reallocation requires the existence of model to be successful."
But who has suggested dropping and recreating model? It was about moving. And whether tempdb is moved before or after model is moved, in both casees it exists. Just in a different location.
"msdb is used by the SQL Server agent and has no bearing on the stability of the database engine."
And how does it follow from this that it can only be moved after tempdb?
Can someone please provide a pointer to some resource (BOL, MSKB, maybe even some non-MS web site) that confirms this?
As far as I know, and as far as I read from Books Online, system databases can be moved in any order you want. Also, you don't have to move all or none, you can just move one or two and leave the rest in the default location.
The only thing I found that is vaguely related is that **IF** you move system databases by detach and attach (not the method I'd prefer - BOL describes a much easier method), and **IF* you also do this for model and msdb at the same time, **THEN** you need to reatrtach model before you can reattach msdb. This is documented here: http://support.microsoft.com/kb/224071.
But unless someone can point me to some documentation I overlooked, I'll have to conclude that this QotD is wrong. It should be removed from the site, as it can only create confusion.
(But seeing that the erroneous March 6 question hasn't been removed yet either, I don't expect this to happen... )
Hugo Kornelis, SQL Server/Data Platform MVP (2006-2016)
Visit my SQL Server blog: http://sqlblog.com/blogs/hugo_kornelis