We have an iSCSI target provided by a CentOS server attached to a Windows Server 2003 Standard box, formatted in NTFS.

My question is this - I know we can resize the backend block device fine (LVM et al.), however how do you tell Windows the NTFS filesystem has shrunk afterwards? [note we want to shrink].

I'm imagining a world of pain if it's not done correctly!

This is a production box, so ideally we'd like the process to keep the drive mounted and online during the process, but downtime can be scheduled if need be.

90% of what I've found on the subject so far basically involves using the 'ntfsresize' command in Linux to do the job -- but surely Windows can do this itself?

Cheers!