DVR systems DVR-HDE-960H-960H2 Series - Manual (Page 67)

Note: If there is only one HDD and is set to Read-only, the device can't record any files. Only live view
mode is available.
If you set the HDD to Read-only when the device is saving files in it, then the file will be saved in next
R/W HDD. If there is only one HDD, the recording will be stopped.
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