How to flush / empty / purge / resize your System Volume Information folder

vssadmin list shadowstorage

[....]
Shadow Copy Storage association                                                         
For volume: (F:)\\?\Volume{7df38471-635b-11e4-9415-000c29dbe934}\                    
Shadow Copy Storage volume: (F:)\\?\Volume{7df38471-635b-11e4-9415-000c29dbe934}\    
Used Shadow Copy Storage space: 249 GB (41%)                                         
Allocated Shadow Copy Storage space: 251 GB (41%)                                    
Maximum Shadow Copy Storage space: UNBOUNDED (2863325530%)
[...]

                        
vssadmin resize shadowstorage /on=F: /For=F: /Maxsize=40GB 

Successfully resized the shadow copy storage association  

If you want to delete a shadowstorage and encounter the infamous error message:

C:\Users\administrator> vssadmin delete shadowstorage /on=F: /For=F:     

vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool      
(C)Copyright2001-2013MicrosoftCorp.                                                                                                                         
Error: The specified shadow copy storage association is in use.                

then use your superpower:

cmd> vssadmin list shadows
cmd> diskshadow
diskshadow>list shadows all
diskshadow>delete shadows oldest F:
diskshadow>delete shadows volume F:
diskshadow>delete shadows all
diskshadow>list shadows all
diskshadow>exit