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zmc does not start with large shared_data_size

Posted: Sat Jan 14, 2006 6:44 pm
by RoRo
Hi,

I'm just doing my first steps with ZoneMinder but am not able to start zmc. My debugging tries show that the requested shared memory size seems to be too large:

01/14/06 18:55:29.199546 zmc_dvideo0[26922].DB1-zm_monitor.cpp/138 [monitor purpose=1]
01/14/06 18:55:29.200652 zmc_dvideo0[26922].DB1-zm_monitor.cpp/141 [shm.size=36864716]
01/14/06 18:55:29.216214 zmc_dvideo0[26922].ERR-zm_monitor.cpp/145 [Can't shmget, probably not enough shared memory space free: Invalid argument]

I extracted the shmget() call to a little test case and found out, that with shared_data_size=36864716, this call always fails with errno=22. I tried a bit deeper and found out that the limit seems to be somewhere between 8.000.000 and 9.000.000, so 36.864.716 is more than four times too much.

But my shared memory knowledge is quite limited, so I don't know what this means. Can I extend shared memory or is there some problem with my installation, which leeds to a too big shared_data_size?

My system: Debian etch on AMD64. Linux 2.6.14.3. ZoneMinder 1.21.4.

Thanks for any help

Roland

Re: zmc does not start with large shared_data_size

Posted: Sat Jan 14, 2006 6:58 pm
by RoRo
RoRo wrote: But my shared memory knowledge is quite limited, so I don't know what this means. Can I extend shared memory
Okay, after writing this down, I googled again and found a hint pointing to /proc/sys/kernel/shmmax.

The command

Code: Select all

echo 60000000 >> /proc/sys/kernel/shmmax
seems to solve my problem. But is this really the correct way?

Ciao
Roland

Posted: Sat Jan 14, 2006 8:25 pm
by cordel
This issue is also listed here in the FAQ>
http://www.zoneminder.com/faq.html

Regards,
Corey