PC DVR Storage space...

[garzajd3 0]

Ok surely I'm not the 1st to run into this. I use PC based DVR systems mainly because when I started they seemed to be cheaper and I can build and configure them myself. I have recently changed the software I use for the DVR side of things. Problem is basically storage space. Seems like most clients out there want and/or need a frame rate of atleast 5fps. So on a system that has 17 cameras with a 250Gig drive I get about 3 days. Now if I throttle the fps down to 1.5 and do the motion only recording then I can get around 7 days.

So my question or concern is that sooner or later someone is going to want a higher frame rate, with a high detailed image, and also a lengthy review time.

Getting the frame rate and quality for recording doesnt seem to be an issue, just getting enough space. Is it typical for these pc based systems to have alot of external storage devices?

I know you can do RAID and all types of daisy chaining for enough drives to fill a small room, but is there some better answer that I'm missing?

I just recently threw out a dual xeon machine out with 5 drives running raid to give me 1 terabyte which I thought would have months of data, but now I"m starting to wonder. Yes I know the more motion you have the more space you need, etc,etc. But surely people using pc based systems arent simply adding usb/firewire devices to add drives... or are they?

Any help or ideals would be useful. And if your going to suggest stand alone units can you please tell me the big advantage. By the way my current systems all utilize network based camera and/or networked video servers.

[scottj 0]

Your choices are either DAS or NAS scenerios. The only things you can do to maximize your storage capacity is A.) Use a DVR with that utilizes a tighter kb/frame compression method, or B.) Add additional disk space whether it is DAS or NAS.

 

Scottj

[Jasper 0]

I use external hard drives to raise the storage capacity, plus the benefit of the user being able to take the hard drive home to review video if they wish.

 

Hard drives are very inexpensive compared to what they were just a couple of years ago.

250GB seems like very little hard drive space for 17 cameras, but I know many people are doing it.

 

Using RAID is good, but you probably should increase the size of the hard drives if your considering going up on the frame rate. 1 Terabyte would be the minimum I would probably use for a 16 camera system.

 

Storage requirements will vary greatly though due to the camera used, the compression methods used and especially lighting issues.

[DingChavez 0]

3 days or 250GB? What kind of file size does the DVR compress the video to? Does it compress at all or just leave it at whatever the camera did? Either way, your application must be extremely busy with lots of activity or your file size is too large. I have a feeling its the latter.

[rory 0]

What type of compression are you recording with.

 

I have a client with 13 cameras ... 640x480 recording with Geo Mpeg4, 4 color cameras, the remainder are BW ... and recording Real time 30fps per channel, on motion detection .. in highest quality recording setting.

 

Its a night club so its open 4 nights a week and thats when the majority of recording is done due to motion, it eats up the HDD on the color cameras especially one of them that is better than the rest with full lighting, file sizes for 5 minutes can be 287MB, BW file sizes are around 90MB for 5 minutes.

 

Addtional occasional recording on the off nights are from low lighting such as pixelising, as well as 24/7 securuity walking around the club, particularly on a couple cameras.

 

Motion is set to almost highest sensetivity.

 

Im getting 11 days with 750GB. Remember the recorded video is in real time though, if i set it to 5fps on each camera, id get more than 3 months as the recorded video sizes drop drastically, by a couple hundred MB, tried it already, but the client wants highest quality and real time as they used to use embedded units, the reason for switching to PC based was this, as well as upgrading options.

 

Note: Pixelising and Color Cameras decrease length of recording, with motion for Pixelising, and color for either motion or continuous. The higher the quality video of a color camera (such as high res in full lighting), will also raise the image size resulting in shorter recording.

 

Using Mpeg 4 over Wavelet or MJpeg will result in longer recording, and in most cases can be as high quality, depends on the DVR used. Tested on the Geo the Geo MPEG4 in640x480 is as good as the Wavelet, with higher compression. Other DVRs will differ though.

 

Rory