Folder sizes on server larger than in original PST

[Andrew Morgan]

On Sun, 28 Aug 2005, Mark wrote:

> Hello,
>
> Perhaps not related to Cyrus, but maybe you guys know why this would be
> like this. I've imported a 650MB .PST file made from Exchange server
> into the Cyrus imapd, who now reports about 870MB. In fact not only
> Cyrus reports it, but it really us that big, according to the OS. I've
> not seen this before, usually the size of a .PST roughly matches the
> size on the Cyrus server after an import. Any idea what could cause a
> missmatch? There is nothing obvious, it seems each email is a bit
> larger than in PST, all adding up to over 200MB of difference. Import
> was done in Outlook by opening a PST as a personal folder, then
> connecting to Cyrus, then dragging and dropping the folders+email.
> Thanks for any insights.

I'd guess it is related to the block sizes on your cyrus filesystem. 
Let's say you have a block size of 4k.  Any file's actual size on disk 
will be a multiple of 4k.  For a 650MB PST file, the most you could be 
"off" the real size is 4k.  When you break that PST out into 1000 separate 
files, you could be off by, for example, 1000 * 2k.

If your block size is larger yet, this effect will be more pronounced. 
See the manpage for "du".

Just a guess...  There may be other factors involved too.

 	Andy