1 Frequently asked questions / Troubleshooting

Frequently asked questions or FAQ.

1. Q: Can I flush/clear the queue (as depicted in Administration → Queue)?
   A: No.
2. Q: How do I migrate from one database to another?
   A: Dump data only (for MySQL, use flag -t or --no-create-info), create the new database using schema files from Zabbix and import the data.
3. Q: I would like to replace all spaces with underscores in my item keys because they worked in older versions but space is not a valid symbol for an item key in 3.0 (or any other reason to mass-modify item keys). How should I do it and what should i beware of?
   A: You may use a database query to replace all occurrences of spaces in item keys with underscores:
   update items set key_=replace(key_,' ','_');
   Triggers will be able to use these items without any additional modifications, but you might have to change any item references in these locations:
   * Notifications (actions)
   * Map element and link labels
   * Calculated item formulas
4. Q: My graphs have dots instead of lines or empty areas. Why so?
   A: Data is missing. This can happen for a variety of reasons - performance problems on Zabbix database, Zabbix server, network, monitored devices...
5. Q: Zabbix daemons fail to start up with a message Listener failed with error: socket() for [[-]:10050] failed with error 22: Invalid argument.
   A: This error arises at attempt to run Zabbix agent compiled on version 2.6.27 or above on a platform with a kernel 2.6.26 and lower. Note that static linking will not help in this case because it is the socket() system call that does not support SOCK_CLOEXEC flag on earlier kernels. ZBX-3395
6. Q: I try to set up a flexible user parameter (one that accepts parameters) with a command that uses a positional parameter like $1, but it doesn't work (uses item parameter instead). How to solve this?
   A: Use a double dollar sign like $$1
7. Q: All dropdowns have a scrollbar and look ugly in Opera 11. Why so?
   A: It's a known bug in Opera 11.00 and 11.01; see Zabbix issue tracker for more information.
8. Q: How can I change graph background colour in a custom theme?
   A: See graph_theme table in the database and theming guide.
9. Q: With DebugLevel 4 I'm seeing messages "Trapper got [] len 0" in server/proxy log - what's that?
   A: Most likely that is frontend, connecting and checking whether server is still running.
10. Q: My system had the time set in the future and now no data is coming in. How could this be solved?
    A: Clear values of database fields hosts.disable_until*, drules.nextcheck, httptest.nextcheck and restart the server/proxy.
11. Q: Text item values in frontend (when using {ITEM.VALUE} macro and in other cases) are cut/trimmed to 20 symbols. Is that normal?
    A: Yes, there is a hardcoded limit in include/items.inc.php currently.

See also

* Troubleshooting page on zabbix.org