The Nx Witness Server application detects and analyzes available storage during the setup process. If not specifically altered Nx Witness will utilize all storage in a system. Storage can also be assigned via the Nx Witness client. Storage options include local storage to the HDDs available on the server computer, Direct-Attached Storage (DAS), and Network-Attached Storage (NAS).
The Nx Witness recording process goes a little something like this:
- IP Video camera streams are detected and captured by the Nx Witness Media Server and stored in RAM.
- The Nx Witness Server writes captured IP video in RAM to available storage (internal hard drives, DAS, or NAS) once per minute..
- All available system drives are written concurrently and according to a ratio the system calculates for their size. So, for example, if a single server has multiple sized hard drives Nx Witness will fill up each hard drive at the same rate to ensure that no single drive's system bus gets overloaded.
- Nx Witness keeps some free space at every drive so that performance is not affected. You can find details about Nx reserved space here: https://support.networkoptix.com/hc/en-us/articles/229345767
- When a drive is full Nx Witness will then begin to overwrite non-locked video starting with the earliest (oldest) video on the server across all drives. Thus solid timeline is guaranteed.
- Since 2.6 version Nx Witness keeps system drive blocked for recording if there's any other drive at server which fits minimal requirements.
- User can not manually modify the archive(delete/add/etc.) using Nx Software
How is hard disk failure managed?
If a single drive in a multiple drive system fails the Nx Witness system will do the following:
- continue writing to all available drives
- create a notification in the notifications panel that a hard drive failure has occurred
- rebuild the archive index after the Media Server is restarted