How WinQuota works
Contrary to many other solutions, WinQuota is complex and efficient solution for your quotas. Instead of periodical scans of certain folders and breaking permissions with limits emulation, WinQuota works at kernel level, intercepts all file activity, and counts quota for all file operations.
This way is more complex, but it much effective and it have no penalty to quota counting for your files.
WinQuota is well-designed application; it uses WDK and IFS Kit techniques to keep your system stable and compatible with 3rd party vendors of anti-viral software. WinQuota does not use any "hackery" techniques like kernel tampering or so; it uses only documented way to manage quotas.
For old systems like WinNT, W2K and WinXP, WinQuota uses file system filter drivers; for modern systems like W2k3, Vista, w2k8 and Win7, WinQuota uses new approach based upon file system mini-ports.
Practically, it can be illustrated as
Often, you can find other solutions:
These solutions working on different principles than WinQuota or Veritas/Symantec, and have no flexibility and efficiency of WinQuota. Only few solutions for Windows really work in real-time.
The typical request handling in WinQuota can be illustrated by the following diagram:
As you can see, WinQuota works with file requests in real-time; it does not provide any checks post-factum. It means WinQuota works as fully-automatic solution and you never have possible races between your checks and your file operations.
Technically, all quota counts are collected at disk in the same place as your files (e. g in folders). This way provides you easy and efficient backup with standard and 3rd party tools. And of course it minimizes penalties for quota accounting, as counters always placed into files and it cached by system together with your files.