ModSecurity failed to access DBM file "/tmp//global"

Question

I have recently setup a new server and starting seeing the following error log entries.

[Sat Jul 14 05:05:00 2012] [error] [client xxxxx] ModSecurity: Failed to access DBM file "/tmp//global": Permission denied [hostname "xxxx"] [uri "/games.php"] [unique_id "UAE2PH8AAAEAAAnZRZoAAAAO"]

and

[Sat Jul 14 04:22:05 2012] [error] [client xxxx] ModSecurity: Failed to access DBM file "/tmp//ip": Permission denied [hostname "xxxxxx"] [uri "/index.php"] [unique_id "UAEsLX8AAAEAAAg0GL8AAAAD"]

/tmp, /tmp/global.dir and /tmp/ip.dir are all owned by root. The weird thing is, the sites get thousands of hits each hour, but not every visit (even to the same URI) triggers the error.

Does anyone have any ideas?

Answer 1

Is there any chance your key+value length is greater than 1008 bytes?

https://www.purehacking.com/blogs/josh-zlatin/increasing-modsecurity-collection-size-limits

Answer 2

In order to fix the above I asked someone to "redo" my /tmp dir