Changing the space assigned to snapshots on PS5000

I have a PS6000 that i am currently implenting. i believe that you can change the snapshot free space within the web management by going into group config -> defaults -> and changing snapshot reserve. This changes for the whole system. Hopefully that works.

That only changes the default setting for when you setup a new volume. I am trying to recover the space that snapshot reserved was using. Currently my settings tell me that I have 20.9% reserved for snapshots and 21% free (which is about 1.07T), but when I try to create a drive through xenserver, it tells me that I only have 159G free; and that free space I have on the dell storage is snapshot free space. There has to be a way to reclaim that space so that xenserver can see it properly.

Per Citrix, an ‘xe sr-probe’ command against the Storage Repository (SR) in question should perform a rescan.
Source: XenServer 4.1.0 release notes (when sr-probe was added):

A xe sr-probe CLI command has been added which performs a backend-specific scan using the supplied device_config parameter. If the device_config parameter is complete the command will return a list of the SRs present of this type on the device, if any. If the device_config parameter is partial a backend-specific scan will be performed, and results will be returned as backend-specific XML to guide the user in improving the device_config parameter.

Customer should, of course, refer to the admin guide for their specific version of XenServer for correct syntax.

It could be xe sr-probe or maybe it is xe sr-scan, one of those two should work.