What does HDD DMA error mean?
Had a power cut today and my CCTV system started beeping and flashing "HDD DMA error" on the screen.
I tried turning it off and on a few times but it still kept doing it so I removed the HDD and hooked it up to my laptop in an external drive caddy, it seemed to be fine, the laptop recognised it and I could copy files to/from the drive no problem.
I formatted the drive hoping it might cure the problem and reinstalled it back in to the CCTV DVR and it's still doing the same thing?
I looked up DMA error but I'm still not 100% sure what it even means.
- 5 years ago
It is an error on the hard drive. Formatting is the right solution, but since the problem still exists, it must be something more serious. The best things to do is to find a CCTV expert like iptechsecurity.com to help you out. Maybe, you have done some errors on the formatting procedures or during the re-installation.
- AdrianLv 75 years ago
DMA is a protocol that allows the drive to read/write direct to ram, bypassing the CPU (but CPU gives the instructions to do so...)
A DMA error on the drive means either the DMA controller on the motherboard is faulty, or the DMA logic is faulty in the HDD itself. Your PC may be able to read the HDD, if it does not "force" DMA modes to be used. All HDD can do "polled" or DMA modes. If not forced to one mode, the HDD may just pick one that works.
However, your CCTV system may be trying to force DMA mode, and that is what is failing. Only way to test where the DMA fault is, is to try another drive in the CCTV system, and see if the DMA fault goes away (then it is the drive). If it remains, it is more likely the motherboard in the CCTV system that has faulted.