• Linux,  Work

    Linux performance improvements

    Two years ago I wrote an article presenting some Linux performance improvements. These performance improvements are still valid, but it is time to talk about some new improvements available. As I am using Debian now, I will focus on that distribution, but you should be able to easily implement these things on other distributions too. Some of these improvements are best suited for desktop systems, other for server systems and some are useful for both.

  • Linux,  Work

    Server migration to Debian

    Since this afternoon, this server is now running Debian GNU/Linux Squeeze. Just like the previous system, this is a KVM virtual machine running on a HP Proliant DL185G5 host. The host server has always been running Debian. This was my last production system still running Mandriva. I might have forgotten to move over a few things or there might be some breakage somewhere, so let me know if you encounter a problem.

  • Linux,  Work

    A wise server migration

    Yesterday I migrated two servers at work to a new machine. The old machines were pretty underpowered: a Pentium III 1 Ghz system (with 384 MB RAM if I remember correctly) and a Pentium 4 system. The new machine is a Dell Poweredge R410 with a Xeon E5504 processor, 12 GB RAM and a PERC H700 RAID controller (which is actually a LSI MegaSAS 9260) with 3 750 GB SATA disks in RAID 5. The hardware is pretty nice (although I am not happy at all with the way Dell treats its customers, so I will rather prefer other vendors in the future, but maybe more about that in a…

  • Linux,  Mandriva

    Migration to virtual machine

    I just finished migrating this website to a new KVM virtual machine. The virtual machine is running Mandriva Cooker (2010.0) now with kernel 2.6.31-rc9 and the virtio drivers. The host machine is a HP DL185 G5 running Debian Lenny (kernel 2.6.26) and kvm 85. During the next days, there might be some short downtime now and then while I continue configuring things

  • Linux,  Work

    Server migration

    Since two days, I have merged the main servers used by two research laboratories at work. One server was an old Linux server which really needed a hardware upgrade, and the other one was a Mac Pro machine running a flaky OS X Leopard. The new server is of course running Linux: Debian Lenny. It was a very interesting experience: working out procedures to migrate the mailboxes (from Dovecot on the Linux server and Cyrus on the Mac server to Cyrus on the new server), finding out how to set up one NIC in two different subnets (especially the routing is a little bit tricky), getting all services hooked up…

  • Linux,  Mandriva,  Work

    Using KVM on Mandriva 2009.0

    Introduction My new Dell Latitude E6400 laptop, is my first system which support hardware visualization. It also has 4 GB RAM, making this an ideal machine to start experimenting with KVM, the kernel based virtual machine system which is now integrated in Linux itself. In the past I had already used different virtualization systems. VMWare Server is annoying because you have to rebuild the kernel modules by hand each time you install a new kernel and it’s not Free (as in Free Speech). Virtualbox handles the modules rebuild nicely thanks to the use of DKMS in Mandriva, but always randomly crashes on an assert, making it totally unusable for serious…