BACK UP: Error backing up .vswp files

[vipclubber]

I am trying to back up entire VM folder to my local PC drive.  It copies everything except .vswp files and sometimes produces File failed to copy using datastore browser.

What are those files? Should they be copied and any idea about the error?

[rcporto]

These files are virtual machine swap files and could be ignored, since they will be created again after you power on your virtual machine if your memory reservation is smaller than the assigned virtual machine memory

[vipclubber]

Thank you. Can you please explain in simple terms what swap file is and the purpose for which it is created?

[Mathieu_C]

The .vswp file is used in case of lack of memory on the ESXi to transfer RAM pages to Storage (same system as OS) after a big overprovisionning (among other), you can choose to place it with VM files or all in another datastore. The size of the file is equal of the memory size of the VM less the memory reservation, but the file is not deleted (0.0 KB).