I want to talk about DVR Storage for CCTV Systems.
A DVR/NVR uses a special type of hard drive that is meant for 24/7 use and constantly writes to it. It also has features to access playback while still recording in the background. Western Digital calls these their Purple Series and Seagate SkyHawk series.
You never want to use a typical Desktop hard drive in a DVR/NVR or any other series really other then the two mentioned. Now Seagate has a white label drive that just says Video 3.5 HDD and those are fine to use as well. However if you plan to use a NAS such as a Synology as an NVR then you’ll need to use drives used for CCTV use.
I get asked this all the time at work after I install a Camera System “How many days does it record?” and a lot of times people get mad at my answer, probably because I can do the math correctly and I know my hardware. But for this post I’ll direct it to a record time calculator.
Keep in mind even if you record only Motion the math uses Continuous recording. Motion Recording is Continuously recording but when it doesn’t see a Pixel change or whatever trigger for it to “record” it will dump that video. What also determines the record time is how many Cameras, their Frames Per-Second, Resolution and Compression type.
A lot of the cheap kits you buy that come with the Cameras, Recorder and Cabling then chances are you have a 1TB drive and can handle a H.264 compression type.
For a example a 4 Channel system with a 1TB drive four 2MP 1080p Cameras with H.264 compression with 24/7 at 15 frames per-second you’ll get 15 days. How ever you might get 25 days with it on Motion if the Cameras have lite traffic.
I personally built my Camera System to my taste. For a example I used four IP Cameras and used different cameras for different locations for the optimum use for the location and used SD Cards until I was able to find a NVR that worked for me. The NVR didn’t come with a drive so I was able to save a few bucks so I could put it towards a Western Digital Purple series 8TB drive. My Cameras and NVR use the newer H.265 Compression so the video is more compressed and still able to have 20 Frames Per-Second at high quality and get about 80 days of record time. I probably spent about two hundred more then a eight channel kit would of cost but I got a better bang for my buck.
The major thing to understand is when the drive fills up it overwrites. It doesn’t wipe the whole drive but it overwrites by day. With an example I will use easy numbers. Say each month is 30 days and the DVR/NVR records for 30 days and the system started recording March 1st. 30 days later is April 1st the system will write over the March 1st entry. However March 2nd is still there until April 2nd then that gets overwritten. and it continues on through out the month.
Another thing to remember most CCTV Systems that are cloud based doesn’t store the video on the cloud. The “Cloud” part is letting you remotely connect to the Camera System to view and playback video from a Phone, Tablet or Computer without having to be a Network guru poking holes into a firewall. Now some consumer Cameras have Cloud storage but they only hold the video for a certain number of days and you have to pay a monthly fee. However some semi professional grade systems will let you sync it to a OneDrive or Google Drive account but you’ll be paying out the butt monthly for that.
Another option is you can add a NAS to the system and the DVR/NVR can upload to the NAS via FTP. However you’ll want CCTV grade drives in your NAS. You could use the Seagate Ironwolf series for the NAS but I don’t think they can keep up with the demand. I had a customer that got me to link his NVR to his NAS and with in a year it wore out the drives he had in it. I have no idea what kind of drives he had in there.
How can I get more record time with my current system?
Do a firmware update, could possibly add more features if the system isn’t too old. Some manufactures such as Dahua added the H.265 compression to their older NVRs that are still in production. If your System isn’t that old maybe a year or so you can see if it has the option to enable H.265. Another option is to turn off unused channels. So if you have a eight channel System and only have six Cameras you can either turn off those two channels or set them to at least Motion. Change the Frames Per-Second to something lower. I typically set the Main Stream to 12FPS and the Sub Stream to 10FPS with budget systems. Put the Cameras on Motion recording or some sort of smart analytics. I would recommend to see if the drive can be swapped out to something bigger but currently since Chia Coin that IPO has been depleting the Hard Drive market and has put Hard Drives on back order and raised the prices to double.
If your current system is five years or older I would honestly upgrade and look for options such as these.
- IP Based
- If you want four Cameras then get a eight channel (comes with a bigger drive)
- 1080p Resolution
You’re looking on the list and probably going “what??!?” Let me explain. Analog is dead, it’s hard to find Analog equipment on the consumer market these days and everything is going IP. H.265 is the new video compression for higher resolution cameras. If you only want four Cameras you’ll probably want more in the future and more channels comes with bigger drives typically so with the four cameras you’ll get more record time out of the box. 4K video is nice and all but in all honesty it’s not much from 1080p and for typical residential applications 1080p is just fine. From my experience most Camera kits that come with 4K cameras the NVR has a typical 1TB drive and even with H.265 you’ll get a week of record time VS 1080p you’ll get 28 – 29 days. If you really want more Resolution then go for 3MP Cameras.
After all the whole point of a Camera system is to catch something devious going on from either a peeping tom or the neighbor’s dog taking a dump on the front lawn. When something happens you want to pull that Video ASAP. Don’t wait more then a week to do it because Murphy’s Law will come knocking on the door. I’ve told customers to unplug their system if it will take me a week to longer to get there. Had one guy wait a whole two months to contact office to pull video from some drunk driver decided to trench the front yard with a car. That guy got a 95 dollar service for me to tell him, “uhh, sorry sir but the playback only goes back 15 days, that will be 95 dollars”. We didn’t know it happened two months ago until I got there.