Shutting down Oracle databases quickly in parallel
patvdv — Mon, 27/07/2009 - 19:08
Most folks running a larger(r) amount of Oracle instances on the one and same server use a sequential method for shutting down their databases at for example backup time or during system shutdown. This can pose some inconveniences and at worst a real problem if it takes a long while before these SHUTDOWN IMMEDIATE commands complete. A concrete example may be the requirement to quickly shutdown your system during a power failure whilst still running on UPS batteries.
To work around this issue I have made a small script that can be used to shutdown a whole bunch of databases in a much faster but yet still tidy fashion. This is archieved by running all database shutdown in parallel and in the background using a helper script and the nohup facility.
Amarok backup script
patvdv — Fri, 05/06/2009 - 15:54
I am a big fan of the superb music player and organizer AmaroK, one of KDE's flagship programs. AmaroK supports multiple database backends for storing information about the music collection (e.g. mp3 files) and until recently I was using the default SQLite backend. The amarok SQLite database is located in the user's home directory and as such it is pretty important to have a decent backup of the AmaroK database in case a calamity occurs. What follows is the listing for a very simple AmaroK backup script that uses the SQLite backend.
Note: you should adjust the variables DUMP_DIR, DUMP_FILE and LOG_FILE variables at the beginning of the script.
Using multiple SSH daemons on one host
patvdv — Fri, 20/06/2008 - 22:01
Recently I ran into the situation where I needed to hook up 2 CentOS GNU/Linux servers to allow the transfer of a large data volume between the both of them. Both servers are internet facing systems and the obvious choice would have been to haul the data across via SCP (secure copy) using the public network interface. Unfortunately, all traffic originating from the public interface was being billed and the entire data transfer would have resulted in a rather hefty bill if I would have used the public internet as transport medium. An additional requirement stipulated that this kind of data transfer would need to happen on a regular basis which would make the use of CD/DVD's rather cumbersome. Since both boxes had a second NIC, the obvious choice was to connect them via a simple cross cable and to use a non-routable IP range for these NICs. Here is a simplified picture of the network setup:
Running UML (User Mode Linux)
patvdv — Fri, 20/06/2008 - 21:50
User-Mode Linux is a safe, secure way of running Linux versions and Linux processes. Run buggy software, experiment with new Linux kernels or distributions, and poke around in the internals of Linux, all without risking your main Linux setup. User-Mode Linux gives you a virtual machine that may have more hardware and software virtual resources than your actual, physical computer. Disk storage for the virtual machine is entirely contained inside a single file on your physical machine. You can assign your virtual machine only the hardware access you want it to have. With properly limited access, nothing you do on the virtual machine can change or damage your real computer, or its software.
HP Proliant HW monitor
patvdv — Fri, 20/06/2008 - 20:54
About
The hppro_hwmon Perl script will query the HP Linux hpasmcli and hpacucli command-line tools to check or show the health of your Proliant hardware. It will check following components:
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Fans
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Memory DIMMs
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Power Supplies
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Server
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Temperature Controls
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RAID Controller
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Physical Drives
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Logical Drives
The default script comes with a standard set of components to check but can be easily customized to fit your needs.
