Oracle: ORA-00257 archiver error. Connect internal only, until freed

Work around for this issue is to increase the amount of space allocated to db_recovery_file_dest; e.g.,

$ sqlplus sys as sysdba
SQL> show parameter db_recovery_file;
db_recovery_file_dest string /opt/oracle/flash_recovery_area
db_recovery_file_dest_size big integer 20G

Compare this with the output of ‘du -sh’; e.g.,

$ du -sh /opt/oracle/flash_recovery_area
21G /opt/oracle/flash_recovery_area

21 vs 20, so set it to something a bit bigger; e.g.,

SQL> alter system set db_recovery_file_dest_size = 30G;

Extracted from this link on


#linux, #oracle

CentOS: httpd invalid command

Was configuring a CentOS 6 server recently, and I decided to comment out all httpd (i.e. Apache) LoadModule directives. Upon restart, there were several invalid commands, so I took the time to note ’em down as it wasn’t obvious (to me, at least) which commands were provided by which modules.

I liken this to a cheat sheet to then:

Invalid command 'AddHandler': mod_mime
Invalid command 'Alias': mod_alias
Invalid command 'BrowserMatch': mod_setenvif
Invalid command 'DirectoryIndex': mod_dir
Invalid command 'IndexOptions': mod_autoindex
Invalid command 'LanguagePriority': mod_negotiation
Invalid command 'LogFormat': mod_log_config
Invalid command 'Order': mod_authz_host
Invalid command 'TransferLog': mod_log_config

#apache, #linux, #red-hat

Windows, Linux (and Samba)

I needed to copy a 140MiB file from a Windows 2000 server. The only problem was that it didn’t support FTP (or SFTP) and I couldn’t download FileZilla Server since there was no network connection. I asked my colleague for a quick fix to this, and I can’t recall what he said, but suddenly I remember that I’d RHEL 3 (and Samba) and I could use Windows to map a Samba share. Problem solved.

Sometimes it is thinking about a problem from a different perspective client/server instead of server/client. Heh

#linux, #samba, #windows

Howto: Check what services are accepting network connections

Use ‘netstat -tnlp’.

$ netstat -tnlp
(Not all processes could be identified, non-owned process info
 will not be shown, you would have to be root to see it all.)
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name
tcp        0      0*               LISTEN      -
tcp        0      0  *               LISTEN      -
tcp        0      0  *               LISTEN      -
tcp        0      0    *               LISTEN      -
tcp        0      0 *               LISTEN      -
tcp        0      0 *               LISTEN      -
tcp        0      0 *               LISTEN      2366/dropbox
tcp6       0      0 :::139                  :::*                    LISTEN      -
tcp6       0      0 :::80                   :::*                    LISTEN      -
tcp6       0      0 :::22                   :::*                    LISTEN      -
tcp6       0      0 ::1:631                 :::*                    LISTEN      -
tcp6       0      0 :::445                  :::*                    LISTEN      -


Using ‘grep’ with Subversion

I use ‘grep’ alot, but it false positives when searching in a Subversion working copy. So I’m using the ‘-r’ flag to recursive search for the phrase ‘quick brown fox’:

$ grep -r 'quick brown fox' *
app/controllers/users_controller.php: quick brown fox
app/controllers/.svn/text-base/users_controller.php.svn-base: quick brown fox

This is only a minor annoyance if there are just two entries, but often that’s not the case. The solution is to add the ‘–exclude-dir=.svn’ flag. But the extra characters causes unnecessary fatigue on my fingers, so I’ve added an alias to my .bashrc file:

alias grep='grep --exclude-dir=.svn'

For maximum mileage, combine this with ‘-ir’:

alias grep='grep -ir --exclude-dir=.svn'

#linux, #subversion

Changing hostname

Should you update /etc/hostname — I did — be sure to update the default tnsnames.ora and listener.ora.

Mine were found in /usr/lib/oracle/xe/app/oracle/product/10.2.0/server/network/admin.

Otherwise you’ll get an ORA-12541 message.

#linux, #oracle

Disk usage sorted by file size

The following shell command runs the ‘du’ command to a max folder depth of 1, and then pipes the output to ‘sort’, and the finally writes it ‘du_log’.

$ du -h --max-depth=1 | sort -n -r > du_log