# nDVR Purging Clarification

**URL:** <https://community.wowza.com/t/ndvr-purging-clarification/37334>\
**Category:** Wowza Streaming Engine\
**Created:** [February 20, 2014, 11:43am UTC](https://community.wowza.com/t/ndvr-purging-clarification/37334 "2014-02-20T11:43:31Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![Kenny\_Griffin](https://avatars.discourse-cdn.com/v4/letter/k/3ab097/32.png) [@Kenny\_Griffin](https://community.wowza.com/u/Kenny_Griffin)\
**Post date:** [February 20, 2014, 11:43am UTC](https://community.wowza.com/t/ndvr-purging-clarification/37334/1 "2014-02-20T11:43:31Z")

</div>

I am thinking of implementing nDVR for a bunch of webcams but I need some clarification on the purging aspect of older files. I know there is a max WindowDuration of 30 hours. So this means I can only let users go back up to 30 hours, correct? I currently have a test application set to 6 hours. After 6 hours, will the m4fv and m4fd files older than 6 hours be deleted automatically? Or will they still be on my server and I need to set up a crontab script to delete them?

---

<div class="post-metadata">

**Author:** ![Daren\_Johnson](https://avatars.discourse-cdn.com/v4/letter/d/ee59a6/32.png) [@Daren\_Johnson](https://community.wowza.com/u/Daren_Johnson)\
**Post date:** [February 20, 2014, 5:58pm UTC](https://community.wowza.com/t/ndvr-purging-clarification/37334/2 "2014-02-20T17:58:28Z")

</div>

Hi,

Right, that’s the maximum for a single recording.

File management is actually explained in this guide [How to plan your Wowza nDVR workflow.](https://www.wowza.com/docs/how-to-plan-your-wowza-ndvr-workflow#outside)

But yes, if the WindowDuration is set to 6 hours, the files will be trimmed/removed to maintain that 6 hours.

Best regards,

Daren