*****
*******, **** ** **** in ************* ~**% ** professional ***** ************ ********.

**** ** ** ******* since ******* **** **** only ~**% ** ******** used ****.
*******, ***** */*** ** integrators ****** *** ****, while ****** **** *** it **** ** *** time.

Larger / ******* ********
*** ****** ******* ******* showed * ***** *********** between ******* *** ****** camera ********. ***** ************ in ******* ****** ******** (~20 ** ****) ****** used ********** (** *** ~20% *****). ******, ***** specializing ** ****** ****** projects (~*** ** ****) almost ****** **** ********** (in *** ~**% *****). In ****** ********, **** install **** ************ ***** to ** **** ********* while *** ****** ** losing ***** ***** ** be **** ******.
***** ********** ******** ******* color ** **** *****:
- "*********, **'* ******** *** all ******** > ** Cameras. ** ******* ********, it's * ******** ** end ***** ** *** it ** *** (*****)."
- "* *** ******* ********** in *** ******** ****** for ****** ***'* ***** only **** * ******** to **** * ****** hard *****."
- "** *** **+ ****** market, ** ******** ****** to *** **** ** all *****."
- "*** ******* **** ***** numbers ** ******* ** use **** * ** these *****. ** ********* raid * ***** ** nice *** '******* ‘*************"
- "**** ** *** ******* are ****** *** *** space. *** ******** ** these ******** ** *** use **** ** ********** for ***** ** **** are *** ******* ******** applications."
- "** **** **** *****/****** to ********** ***** ***** and ****** ***** ** a ******* *** ******** out * ****-***** ******* for ******* ** * plus *** **** ********** and *** ****.
- "*** ***** ************* (*-* cameras) ** ****** ** not *** *** ********** or, ** ****, ****** two ******. ******* */* of *** ***** ******** use *********. *** **** small *********, *** ******* is *** ** ********* that *** **** ***** failure *** ******* **** is * *** *****."
Reasons ***
********* *** ***** ** surveillance *****, ******** ** the **** ** ****, was *** **** ****** reason *** ** *** RAID:
- "******* ***** *** **** as *********** ** ******* who ********** *** **** for ********** **** ******** data *** *** **** reason **** ** *** as ********* **** ******** video."
- "** ***'* **** ********* that **** **** ** pay *** **********."
- "******** *** *** ****** to ******* **** *** footage ** *** **** sensitive *** ** *******."
- "********* ****** ***** *** extra **** ** **** video **********."
- "** **** **** *** ******* are **** ********** ** longevity ** ********* **** redundancy."
- "**** ** *** ********* come **** *** *** world ***** **% ** the **** ****'* ***** RAID *******. **** **** in ****, ***** ********* already **** ******** *** risk ** ****** ******* if * *** ****. Plus, **** ***'* **** to *** *** ***** money *** ****."
- "* **** ***** *** customers ** **** ***** like *** ****** *** explained *** ******** *** they *** *** *** the ***** ********* ** the ****.”
- "***** ** ****** ***** adding *******, ***** ****** storage. **** **** ** strongly **** **, ****** simply ** *** **** to ***** *** *****."
** ******, **** **** be ********* ***** **** sentiment, *** *** **** smaller *****, *** ********** that ******** ******** **** be **** ** *** due ** * *********** of (*) ********** ******* and (*) ********** ******.
Redundancy **** - *, *, **
***** *** *** **** common ****** *** ***** was * ****** ******, up *** ****** ** this ****** **** ** 2012. ******, **** * number ** ******** ** RAID10 **** *****:
- "**** ********** ***** **** 5 ** *** ********** (about **%) **** ****** sites **** * ***** 15%"
- "* ***** **** ** use ***** ** **** cases. **** ***** **** up *****."
- "***** **% ** *** CASINO ************ *******. ***** 70% ** *** ****** SURVEILLANCE *******."
- "* *** **** * on ***** *-**** ************* and **** * *** bigger *************."
- "** ****** **** ** use **** * ** RAID * ** **** too *****."
- "** *** **** * for **% ** *** sales. *** ** **** requires ** ** ** a ***** *******, *** client ***** *** *************. the ***** **% ** sales *** ********** ******* we *** **** *"
- "**** ** ****** * disk ***** ********* ** a ****** ******** ******"
- "**** ******* *****, ** prefer **** ** ****** a ******* ** ***** drives *** ******* *****, or * ******* ** 5 ****** ******* ***** (n+2) ***** * ** an *** ****** ******* than *... *** ******* online *******."
- "**** * ** ******* systems ***** ** *******. Larger ******** ** **** use **** ** ** the "**** ********" ****** and **** * ** the "*******" ******."
- "**** * ** * fundamental ******** *** *** office. **** * ********** replacing * **** ** typically ********* ** ********* that **** ****** * really *****/******** ****** ** staff, **** ***** ** customers **** '******' ******* staff *** ********"
- "***** **** * ** 6. ****** ** ******* pushing **** ******, *** customers **** ********* *** ignoring ***** ***** ************ for ***** *** **** coming **** ** **** out **** ***** ******-***** recorder *** * ***** failure ** *** ********."
** * ***** ************, RAID5 ** *** ***** costly ** ** **** only * ********** ****** for ******** ******. *******, the ***** ******* **** RAID5 ** ****** * second ***** ****** ********** from *** ***** ****** drive. ******, ******* ***** are *********** ** **** drives *** ******, ********** this ****. ******* ** that, **** ***** *** choosing *****, ***** ******** 2 ********** ******, ******* its ****** **** ********. Finally, ****** (*** *+*), everything **** *****, ******** faster ****** *** ******* times **** **** * and *, ** *** expense ** ********* * additional ***** *** ***** drive ****.
Comments (22)
John Honovich
Btw, this question / topic came up in the current IP Networking class. Keep the feedback coming in as this helps us prioritize what to cover.
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Undisclosed #1
I would be careful when using the term "redundancy". In the IP video space terms like redundancy, failover and high availablity are used often, in many cases incorrectly. This article speaks to RAID as a solution for storage "redundancy" however many times "redundancy" can be misconstrued as solution for a catastrophic server failure. Just a thought.
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Matt Ion
It's almost an all-or-nothing with our customers. Pretty much all of the smaller/individual retailers just rely on the DVR/NVR's internal drives, and if a drive fails... oh well. Usually if they need to review an event, it's within a day or two of it happening; long-term events are things involving big bucks and more of a concern to the parent company or outside vendors (lotto, credit cards, etc.), and if the video is gone, it's someone else's problem.
The only customer that does use RAID storage, it's still on less than half their sites, but for almost all sites that have it, we're using RAID6 with a hot spare. There was actually one case where we had a drive fail in a RAID5 array, and then another fail before the array had finished rebuilding on a replacement drive, resulting in the loss of everything. After that the decision was made to go to two-disk redundancy, and since it's not always possible for someone to get to site right away to replace a bad drive, the hot spare was decided on as well. So far there have been no data losses on those systems.
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Rob Hammond
This thread is helpful to us on the design side, understand what you guys on the install side are experiencing!
To reiterate what 1 said above, RAID is not redundancy, it is resiliency, true redundancy would be a separate server mirroring the active server; on active server fail, auto switch to the backup server - I have never heard of this type of deployment in video surveillance.
Another redundancy solution is to store locally when the server goes down, the camera detects a server failure and it stores locally, until the server comes back on line. My question is how well does this work in the real world, we have SD cards in most cameras now, have people been deploying this as fall back? Does it work as advertised?
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Tariq Saleh
Hello,
RAID 6 is better than RAID 5 in terms of redundancy. However, the RAID 6 has write performance penalty due to overhead associated with the parity calculations. RAID 6 performance varies depending on the manufacturer’s storage architecture.
Thanks
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Alan Nagl
This conversation is really interesting to me. During the past couple of years, few of my/our customers report using RAID 5 or higher, and now this poll shows it has grown to >50%.
As a hard drive guy, I tend to think of RAID as an insurance policy. It can provide partial protection against data loss, but it comes at a price, and it is not 100% protection.
Also, it's important to remember that RAID5 and higher is actually a tougher environment for drives. Given the same model/same capacity, drives running a RAID5 or higher file system will have a slightly higher failure rate...
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Alan Nagl
Well, certainly it does vary, depending upon their segment of the market and their tolerance for cost, but for us the WD Purple series is by far the favorite.
We also carry the Purple NV, which is a better choice for RAID5 and higher file systems, and of course, the Enterprise class drives are picking up steam as the larger NVRs come into their own.
I'd say we're seeing 90% traditional streaming drives (Purple), 5% entry level RAID (Purple NV) and 5% Enterprise class (WD Re).
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Alan Nagl
More RAID 0/1, then RAID 5. 6 seems rare, but I'm not sure why.
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Luis Carmona
One aspect of RAID I think some people miss and need to be careful about, is where is the RAID parity written or stored? I remember there were some lesser expensive RAID controllers that stored parity info in the RAID controller. That meant if the controller went bad, you lost all your disk info. Most however write the parity info on the drive. That means if the controller goes bad, or you want to move the disks to another chassis, you can do so and the RAID info can be read by the new controller and all data will be there and accessible.
It's been awhile since I've researched and worked with these nuances of RAID controllers, and maybe that's not the case anymore in some controllers that RAID info is only in the controller. But anyone using RAID should ask the question, "What happens if my controller fails?"
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