Is it possible to adjust the size of a vm's hard disk image, say I have a 2008r2 vm with a 500gb disk and I want to increase it, can it be done safely or is that not how to do it?
Also, is it possible to reduce it if most of it is unused?
increasing is very easy (assuming your guest has no snapshots and the LUN has enough free space). You can use the vSphere Client to change the provisioned size of the disk. From there in 2K8R2, go to disk manager and extend the volume.
Reducing is best done using VMware Converter
Yes it is possible - earlier versions of Windows the system drive could not dynamically expanded so there are some tricks that can be done as well as software that allowed for exoanding the partition -
Decreasing a disk is trickier because you can run into issues of corrupting the parititon - the best way to do this is use VMware converter and resize the disk smaller -
Of course!, I had forgotten about moving the partition boundary, new to all this in a virtual world I have had good success increasing disks and some very bad results in decreasing them In the physical world so I guess it's the same then.
Can I V2V with the converter without using vcentre??