VSM 7.5 - Storage Requirements for the Metadata Server

Jonathan Young · ‎04-04-2014

For the Media Servers, there is a formula you can use that will tell you how much space you need based on the expected number of cameras, bit rate, frame rate, and retention period. Requirements change, but this at least gives you a baseline or starting point of how much space to assign to the system.

For the metadata server, is there a similar formula that should be followed or some way of determining a baseline amount of storage to add?

I'm setting up a lab environment to test this new server type out, mainly for the luminance data to be used for motion analysis. I'm going to add 1TB to it to start (probably way too much for a 20 camera lab, but since it will be thin provisioned, I don't care at this point).

Any thoughts, considerations, or recommendations from those that have already set this up? Hopefully I'll have some of my own early next week after playing with it for a bit.

Scott Olsen · ‎04-07-2014

I don't believe I've seen anything regarding this yet either.

I don't see much in the way of technical details regarding what data is actually stored, but admittedly, I haven't taken a look at any of the published API detail.

I think you might have to do your own testing in a lab environment to come up with your own prediction algorithm. I've made my own custom VMD tracking spreadsheets and scripts to calculate actual 'real world' storage requirements for some of our installations that utilized a combination of both continuous recording and VMD. All other variables being equal (bitrate, retention, etc...) we're able to compare the VMD storage values to a reference "continuous archive" storage total to derive each feeds "effective duty-cycle". If you were also able to isolate and track this additional metadata storage requirement on a per-camera basis, you may be able to get the detail you need to come up with a rough algorithm or "metadata factor" that could be used to estimate additional storage requirements.

Sounds like fun. I wish I had the time to experiment myself!

Best of luck, and don't be afraid to share :-)

Scott Olsen

Solutions Specialist

Bulletproof Solutions Inc.

http://www.bulletproofsi.com

Scott Olsen Solutions Specialist Bulletproof Solutions Inc. Web: www.bulletproofsi.com

Jonathan Young · ‎04-07-2014

It looks like the correct answer is......very little. After capturing a weekends worth of luminance data, I looked to the media volume and there is nothing there except the default storage scripts. This makes me wonder why it even required me to add the media volume in the first place. My assumption is that they copied code from adding a media server and forgot to remove that check, or they are planning ahead for additional features on the metadata server.

I haven't had a chance to see where it is placing this data. I saved a disk usage report and will use this to compare what I have in a few days to see where the culprit location may be.

My first impressions of the new metadata server are good. I like how quickly it is able to pinpoint motion in video. I searched a period of 8 hours and received results in less than 30 seconds. This is lightning fast compared to the 6.x way of motion analysis.

Scott Olsen · ‎04-07-2014

Interesting. I haven't had a chance to try it out yet, but if I had to guess, I'd say that the metadata is being index in a mysql database of some kind.

Keep me in the loop with what you find out!

Scott Olsen Solutions Specialist Bulletproof Solutions Inc. Web: www.bulletproofsi.com

Jason Rossi · ‎04-12-2014

I haven't deployed mine yet but I was informed by a knowledgeable Cisco engineer that the metadata server acts as temporary storage when a metadata search is initiated. So it is only used on demand, and for up to 5 cameras being searched at one time. Therefore minimal storage is needed.

I suspect a dedicated server is needed not for the storage requirement but rather due to CPU load required during the search.