HPE Storage Users Group

No the defrag and compact are not the same. The defrag process is an array internal process that occurs periodically (there is no way to control this manually today). The defrag process wakes up periodically and scans for VV's with free reserved space, once found the system will attempt to defrag the pages into contiguous 128MB regions. Once you have contiguous 128MB regions these are returned back to the CPG for reuse by any volume using that CPG. The CPG compact process then collects these 128MB regions from the owning CPG and returns them back to the system as a whole for reuse by any valid CPG.

"My backup solution is VEEAM, which makes a snapshot of each vm each day, and removes it afterwards. That, i assume, will also take up space after deletion?"

If the Snap VV is deleted after use, then the space will be returned to the CPG for reuse by any VV or snap in that CPG, if you have enough returned space then the compact CPG will return this to the system. However there's no need to run the compact so often, the returned space is already available for reuse within the CPG for your growing volumes or next set of snapshots. As such assuming you compact and return the space to the system nightly, the next time the CPG grows to accommodate writes it will just claw the space back, so you're probably just making the system work harder than it needs to.

I see, ok.

Well yestoday i ran the vmware commands on our lun's, and i was able to free up almost 300 GB on one of the luns - however the 3par console says something different. Here is a few screenshots to explain:

What are headings you are looking at in the GUI, "Used space" or "Reserved Space" ? They're cut off in the screenshot so impossible to compare to the CLI output, also the GUI will trail the CLI on reclaimed space so the CLI is the best indicator. In your case it's showing

983,680MB Reserved of which 921,152MB has been written
After the reclaim you have the following
938,752MB Reserved of which 630,709MB is claimed as used so 290,443MB's was returned for resuse by the VV.

In the above you can see the system has already reclaimed some of the Reserved space 983,680MB - 938,752MB = 44,928 MB / 128MB region = 351 x 128MB regions, which will be returned to the CPG and if you run a compact CPG ultimately to the system as a whole. This is the defrag process in action and it will steadily return space but not at the speed of the VV reclaim. First it targets the non fragmented regions (as above, low hanging friut) and will slowly defrag and return the rest to the CPG over time. It's designed to be non intrusive and also your VV might decide to grow again, so why do unnecessary work if the space is just going to be overwritten by the same VV in the very near future.

Note if you want to circumvent this process then you can convert the VV from thin to thick and back to thin again, assuming you have the space and this will defrag the VV on the fly and return the reserved space immediately.

The Reserved vs User space, Reclaim and Defrag processes are covered extensively in many other threads on this forum.