Compared ** *********** *** **** **** *******
****** *** ************ ******* ***** **** use ** *********** *******, ******* ** is * *** ****** ** ** NVR ** *** ********. ***** ** captured ** * ****** *** *********** to * '*******' ******** ***** ******** video ***** *** ******** ** *** same **, ****** ** *********.
****** *************, **** **** *****, ********* have * ******** (** ********* ********* on ****** ** *******) ** **** site. **** *** ** ********** * form ** '**** *******' *** ** is *** ****** ***** **** ******* but ********* ******** ** *** ****.
** ********, **** **** *******, *** video ** ********, ******* *** ****** right ****** *** ****** ******. ***** does *** **** ** ** **** out ** *** ****** ****** ******* wants ** **** **** ***** ** review ******** *****. *******, **** ** cameras ******* **** *******; **** ** not ******** ** ****** ** ** SDI ******* **** **** ** ******** their ***** ** *****-***** *********. ** cameras **** ****** ** ***** *** local **** ******* *** *********** '****** channel ****" ** **** ******* **** video ******* *** ********* ** ***.
***** ***** *** ** ******** ** many ******* *******, *** **** ******* are** *****:
- ** **** ***** *** ********** ***** into ******* ******** ******* ** ** plugged **.
- ** *** ****, * *** ************* (e.g. *******) ***** **** ****** **** the ******* *** *** *********** ********* size ************ **** **** *********.
- ** *** ****, * *** ************* allowed ******** **** ***** ** ** connected ******** ** *** ******.
Common ************
***** ********* ************ *** **** ****** for **** *******:
- *** ****** ***********- ******* ** ******* ** * server ** ********* ** ***, **** record ****** *** ****** ***** **** storage *** ******* ** ***** ******* directly ***** * ******. **** *** the **** ****** ** ***** **** a ***** ****** ** ******* ** VMS ******* ********* **************** **** *** complexity ****.
- ******* **** *********- *** *** ********* ********, **** wireless, ********* ****** *** ****** ********* reduces *** ******* ** *** *******. Instead ** ********* ************ ** ******** there ** ******, *** ***** **** is *********** **** ******* ***** ** watch **** ** ** ** *************.
- ********* **********- **** ******* *** ** **** as * ****-** ** ********* *********, ensuring **** ** ***** ** **** even ** *** ******* ********** **** down *********** ** *** *** / NVR ** ******* ************. **** *** connection ** *** ******** ** *************, the ******** *** ******* ***** ****** during *** ******** ** ** **** from *** ****** ** ** (****: must ****** *** ******* *** **** feature *** *********** **** ******** *******). Redundancy *** **** ******* ** **** often **** ** ***** *****, ******* critical ************.
Camera *******
************, ** **** ******* ** *********** for ** *******, **** ** ***-****, low-end ****** ** *********** ** ********** cost.**% ** ** ************** ******* ******* ** *** **** Camera ****** , ****** *** *** SD *****.
***** *** ***** ********* *********** ********** encountered:
- ******* ****
- ******* ***********
- ******** / ********* *************
Storage **** ***********
** ****, *** *** ******* **** per **** **** ** ** ******* ranges **** **** ** *****.
**** ** *******, ********** ***** ****, only ******* **** *****, ******** ******* to ****. ***** ******* *** ******* SDXC, ***** ******* **** **********. *******, regardless ** *** ** **** ******* supported, **** **** *** ************ ******** the ******* ******* **** **** *******.
** ********, **** ** ******** ****** common ***, *** *******, ** **** Axis *** '************' ** **** ********* ******* ***** ** *****.
**** *** ****** ** ********** ** a *** ** ******* ********, ***** for *****'* ** ***** ** *** a *** ** *******. **** *** camera, *** **** ** **** ****** depends ** **********, ***** ****, ***********, motion ** ********** *********, ******** ******, etc. **** ****, ******* * ***** of ********* **** ** **** **** without *********** ** *** ** ***** key ********** *****.
Storage ***********
** *** **** *** *****, ******** over **** ******* *********** **** ****** very ***********. *** *******, ***:**** **** ******* *** ****** ********* Is *************** ****** **** ********* ********, ****** Solution. **** **** *** ******* ***, at ***** ********* ******* **** *** a ***** ******* *** ******** **** storage *******. *******, **** ******* ** issues **** ***** ******'* **** ******* also **** ********.
*** ***** ****** ** *** *** of ***** '*******' ** *****, ** SD ***** ***** **** ****** ***** giveaways ** ********** *********. **** ******** people ********* ***** ** ** *****, though ** ******* **** ** ************ as '*****' **** ******** **********, **** part ** **** ** ******** *** reliable *******. ********, *******, *** *** taken * *** ** ********* *** its ***** ** ************,******** * '************ *********' *******, ****** **** ** **** *** and **** **** **** *.* ***** effective ********.
****** ****: ******* *********** ** * concern *** ****** *** ****** **** storage, ***** **** **** ******** ****** supplier ** **** **** ********* *** are ******* ** ******* / ********.
Third ***** *************
*** ******* ******* ***** **, *************, the **** ** * ** * years ***. ***** ***** *** ******* for **** ******* ******* ****. **** if *** *** ****** ***** ****** a ******, ** **** *** **** you *** ****** ******** **. **** IP ******* ******* ** ***** *** only ***** *** *********** ******* ** individual ***** *****. **** **** ******* VMS *********** *** **** *** ***** own ***, *** *** ***** *******.
** *** *********** ****, ***** ********* expect ** ******* ****** ** ************'* cameras ** * *** *** ****** them ***. *******, **** **** *******, most ***** ******* ** ******* *** the *** **** ** ******* *** party ****** *************, ********* **** ****** Axis. **** **** **** *** ****, Genetec ****** *** *** ****** ***** party **** ******* ******* *** **** is ***** * ******** ** *** cameras.
*** / ***: ****** **** **** choice ** ********* *** ***** ********* with **** ****** ** **** *******.
ONVIF ******* *
* ***** ***** *******, *, **** to ******** ******* / ********* ** recorded *****, ** *******. **** *** the ********* ** **** ***** ***** systems ********** ** ***** / ******** as **** ** ***** / ******** integrating **** ****** **** *******. ** the **** ****, ******** ****** ******* for ***** ******* * ** *******, with *** ****** ** ** **** 2015. *******, ** ***** *** ********** supporting ***** ******* * ** **** time, ************* ************ ******** ************** ** ***** * ******* ** it*** ***** **** *******.
******* * ** ****** ******** *** not ** * **** **** ****. The *********** **** ** ***** **** today ** **** ** *** *** it **** **** ********* ** **** reduce *** ***** ***** ************* *******.
Edge ******* *********** - ****** ** ***
*** ***********, ****** ** ***, ****** be ********** *** ***** *** **** to ********* *** ******* *** ****** less ********* ***/** ******* ******* ** storage. *******, **** **** **** **** if ***'* ****** *** ******** ****** to *** *********, ***** ** ********. See ********* ** *************** *** *** **** *** **** of ****.
Stealing *******
***** ******* *** ****** *********** ****** and ******* ** **********, ***** **** storage ***** ******* *** ******** ***** wherever *** ******* ***. *******, **** makes ** ****** *** ** ********* to ******* ***** ********. *** **** need ** ** ** ****** *** back ** *** ****** *** **** out *** ****. *** **** ** a ********* **** **** ** *** whether ***** **** ****** ** **** vary ***** ** *** ******** ******** of *** ************. ** ****** **** high ******** ********** ** **** **** as ************ ***** *** **** ** the ****** ** ** **** ********* about ****.
The ******** **** *** **** *******
*** **** ******** **** *** **** storage ***** ** ******, **** ******* systems **** ***** **********. ** ***** systems, ***** ***** ********* ******** ** corporate ** ********, *** *********** ***** of * ~$*** ** **** *** camera ** *** *********** *** *** likelihood **** *** *** ***** **** supports **** ********* ** ******, ****** not *******.
* *** ***** ***, ***** **** storage ** ********* *********** ***** / recorders *** ********** *** *** **** has ****** ****** *****. *** ***** who ****** ****** *** ****** ****, HD ****** *** ******** * ******* and ***** **** *********** ** ******* this. **** **** ********* **** **** Camera *********, ***** *** ****** **** of **** ******* *** *** ~$*** SD **** **** *** ****** ****** come ***** ** *****, ********** ***** HD ****** **** *** ** ***********.
*** *****, ******, ***** **** ******* replacing ***** *** ****, ** ** only * *** ******* (*, * or *) ** ****** *** ****. In **** *********, *** **** *** complexity ** ****** * ******** ********* a *** ** *****.
Future ** **** ******* / *********
**** ******* ** ********** * ***** in **** (******* **** ******* ***** **********).
*** *** ******** *** (*) ***** party *************, (*) *********** *** (*) size. ****** ***** *** **** **** progress ** **** ***** **** *** past *** *****, ** ** *** fast. ******, *** ******* ***** ******* looks ** ** ** * ******* pace. ** ****, ******* **** ******* when ***** **** *******.
****: **** ** * ************* ******* version ** ******* **** ******* / ********* ********.
Comments (16)
Dale White
John,
Thanks for this. Maybe the manufacturers on here will move toward improving the offerings in this area. I have advocated for edge storage for a long time. Many other technologies moved intelligence and data to the edge years ago e.g access control. At one time, all access control decisions were made by a central processor which limited response time etc., but that was 30 years ago.
To me, I guess it's just logical to keep your data locally and only access it when needed. I wonder if use has improved since your 2012 article?
We spend a lot of money shipping huge amounts of video data around to massive storage arrays, clouds, etc. Our studys have shown that <2% of video is ever actually used. So at a site with 24TB of storage you're just hogging the network infrastructure for no reason.
That's like having a 15 ton dump truck deliver a shovel full of dirt. We have a ways to go in this area but the time could be short with the right company and resources.
Given the average system size, reliable, supervised edge storage would simplify a lot overly complex installations. Not sure why it hasn't been a priority before now.
Can't wait!
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Undisclosed #1
Some good points, a few things I'd mention as well:
The two big limitations of edge-storage are overall card size (in GB) and difficulty in accessing the video (both of these are mentioned, I'm just confirming/rehashing). Edge storage is great for cases where you only have a small number of cameras and will need to access/retrieve recorded video very rarely.
I disagree with this statement though: This is not possible in analog or HD SDI cameras that need to transmit their video to stand-alone recorders.
Edge storage is really just storing the video in a way that keeps the traffic off the network. Cameras directly connected to an NVR/DVR would really be edge storage by most practical definitions.
Something else not mentioned in the article is the use of edge storage for network load management. I see/hear people ask about this a lot, and it doesn't work like that. Generally speaking, if you don't have the bandwidth to record video live, you won't be able to "buffer" it in the camera and move/trickle it to some centralized recorder later.
In terms of SD cards, I'd strongly suggest budgeting for a 3 year replacement cycle. You can use the data sheets from most of the popular cards and some basic math to calculate an expected life span, but in my experience there is more to it than just the total number of write cycles.
The good news is that bad SD cards will tend to show their flaws pretty early, and you can catch some of this before installing them in the field. Essentially:
1) Determine how much data you will use per day (within a few GB or so, it doesn't have to be perfect). Let's assume you're storing 30GB/day.
2) Multiple your daily storage by 90(days) for a total, 2700GB in this case.
3) Take your SD card size and divide the number above by your card size (eg: 2700GB/128GB card = 21.09)
4) Create a set of 3 random files, each that is a little bit smaller than your card size (you're going to copy this file to the card and you want to make sure you don't get an error from the file being too big for the card after your OS puts some crap on the card first).
5) Mount the SD card, copy thr first file, when that completes delete it and copy the 2nd, then the third. Do this process however many times simulates 90 days (eg: 21 times in this case).
6) Use a utility like this one to check the card for errors. If there are a high number of errors discard or return the card.
Or, to state the above another way, I've seen a lot of cards fail in the first 60-90 days, if they last that long they'll probably last a couple of years. You can simulate a bunch of write-cycles with some script-fu on linux or Windows and catch faulty cards before they're 100 miles away and 20 feet in the air.
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Undisclosed #2
If I'm understanding you correctly, this seems odd. I don't doubt that there is a good deal of variance in reliability of cards even of the same type and capacity, but it is well known that these cards lifespan is limited by the total number of cell rewrites, at least for the working ones.
Needlessly simulating 90 days of writes would be expected to reduce the lifespan of the card by 90 days on the ones passing the test. Do alot of them fail in just 2 or 3 days? Maybe that would be enough to eliminate the worst cards.
Why disagree? I suppose that SDI cameras could record uncompressed video to the SD card, but I would imagine that would fill up in a matter of minutes. As for any analog camera, I don't see how its possible at all.
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Undisclosed #1
It would *sort of* reduce the lifespan, but not as directly as you think.
The cards have a spec that lists the number of overwrite/bit flip cycles before major degradation, and loss/corruption of data, occurs. The majority of the cards will fit to this spec (actually, exceed it) and everything is OK, but some will not.
I'm not saying this is an exact science, it's just some recommendations based on observations. 2 or 3 days worth of testing would only equate to 1 or 2 complete flips of the card data, almost no name-brand card should fail that quickly.
This is really no different than the burn-in tests typically done with components. Due to the nature of the SD cards being installed in the cameras it's generally not easy to just walk up and replace the card. Also, because of the way they fail, and the fact that many cameras still don't do much to check card integrity and report errors (last time I looked, over a year ago), you can end up in a case where your card is either completely dead, or at a very reduced capacity. If you are not regularly accessing stored video to verify the integrity of the card you will end up in a case where when you need the video it's not going to be there.
If the card can survive a simulated 90 day stress test there is a higher chance that it will go on to be reliable. I also feel that if you're using SD cards exclusively you need to setup a maintenance window that gives you a good margin of error. If a 90-day reduction in lifespan (and again, it's not direct) is going to be a major factor, then you should be using larger cards or not relying on edge storage for your solution.
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Alexander Gutierrez
My experience with Sunell OEMs when using Edge recording (on Micro SD Slot): For a strange reason the Clock resets, so the recording is affected, either the camera does not record or the recorded file has a false Time/Date info. This need to be checked when testing these kind of solutions. Sunell provides a NTP tool but this is useless when you want to apply to real life situations because you are only installing a camera with no local VMS / NVR.
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Joe Jones
John,
I was wondering if there has been any newer research done into edge recording since this article. I know that the storage capabilities have evolved quite a bit and was wondering about 3rd party support and other features.
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