ZoneMinder Forums

gmar_87 wrote:I am trying to get some spare USB webcams working with ZoneMinder, but having some problems. I can get one sort of working at 320x240 but if i increase pixels or image frame size i get the following in the syslog.

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2011-09-13 19:39:41.584021	zma_m2	2087	ERR	Got unexpected memory map file size 23041284, expected 5761284	zm_monitor.cpp	364

Is it possible to increase mapped memory? If so, how?

mastertheknife wrote:

gmar_87 wrote:I am trying to get some spare USB webcams working with ZoneMinder, but having some problems. I can get one sort of working at 320x240 but if i increase pixels or image frame size i get the following in the syslog.

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2011-09-13 19:39:41.584021	zma_m2	2087	ERR	Got unexpected memory map file size 23041284, expected 5761284	zm_monitor.cpp	364

Is it possible to increase mapped memory? If so, how?

You need to restart ZM after changing settings such as the resolution.

mastertheknife

nightcrawler wrote:gmar,
Mapped memory allows you to use a special type of file as the placeholder for your memory and this file is "mapped" into memory space for easy and fast access.
To enable mapped memory in Zoneminder you need to add the

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--enable--mmap=yes

switch to your configure line. IE: etc/zm/zm.conf

look if your linux has an mmap drive. usualy it is like /dev/shm. (see the wiki: http://www.zoneminder.com/wiki/index.php/FAQ for mmap)
You can check it with command:

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mount | grep shm

An line is send back if you have it like :

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none on /dev/shm type tmpfs (rw,nosuid,nodev,size=512mb)

look to the size! if it's less then your system RAM than Increase it with an remount command

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# mount -o remount,size=1G /dev/shm 

and check it again


Now set in Zoneminder options path > PAT_MAP to /dev/shm (default!) and restart ZoneMinder, to check the memory slices use "df" and relating to just ZM type

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ls -l /dev/shm/zm*

(you can leave the /zm* out of it if you want to see other users of the swap space)

and if it's set you can increase your camera resolution,buffer etc. if the cam stops working restart zoneminder like mastertheknife says in his post. the mmap only increase if you restart ZoneMinder.
(It personally has takes me a few days of google-in before I found this "bug").

df -h

mount | grep shm

 ls -al /dev/shm

total 74424
drwxrwxrwt  2 root     root          100 2011-10-10 19:55 .
drwxr-xr-x 19 root     root         4340 2011-10-08 11:17 ..
-rw-------  1 www-data www-data 36865524 2011-10-11 08:45 zm.mmap.1
-rw-------  1 www-data www-data 36865524 2011-10-11 08:46 zm.mmap.2
-rw-------  1 www-data www-data  2305044 2011-10-10 19:55 zm.mmap.9