Consistently backup your virtual machines using libvirt and zfs – part 1

How to backup virtual machines is a pretty interesting topic and a lot could be said. COW file systems like zfs or btrfs actually do most of the job for you, thanks to their snapshotting capabilities. Unfortunately that’s not enough to get consistent backups, because taking a snapshot of a running VM is very similar […]

Optane 900p 480G: zfs vs btrfs vs ext4 benchmarks

I recently bought a new server with an Optane 900p 480G and I decided to give zfs a try instead of using btrfs as usual (I will not use raid or other devices, just a single 900p).

I will use my Optane drive to host several KVM virtual machines.

I have been fooled to think […]

Asterisk Debian Squeeze packages with T.38 gateway, queue hints and fixed RFC4235

After releasing a patch against 1.8.11 I made Debian packages compiled with T38 gateway support. Also, I backported a fix which should (hopefully) fix call pickup with RFC4235 (notifycid=yes) and a new feature which allows to place a hint on a queue.

Here is linuxsystem’s repository:

Stay tuned for updates.

New T.38 gateway patch against Asterisk

Yesterday Asterisk- has been released, unfortunately latest irroot’s T.38 patch is still against 1.8.8. Since I’m going to upgrade my asterisk box I made a new patch out of his subversion branch and I ported it to 1.8.11. I still didn’t test it properly, but I will in the following days. Debian Squeeze packages of […]

Fast SSH file transfers with HPN patches

This is a common problem: you have some big files (for example a disk image) to transfer over a Gigabig Ethernet link and it takes too much time with SCP/SFTP . Also you probably don’t want to bother installing an ftp server, then what’s the answer?

It’s called HPN-SSH and it’s a patchset you can […]

x86_64/SSE2 optimized Serpent cipher algorithm: 3x faster

Yesterday linux 3.3.0 has been released, one of the less talked features is the new assembly optimized Serpent cipher algorithm.

Serpent is a symmetric keyblock cipher which was a finalist in the Advanced Encryption Standard (AES) contest, where it came second to Rijndael. Serpent was designed by Ross Anderson, Eli Biham, and Lars Knudsen. Source: […]

IPv4 vs IPv6 1Gbps network performance

Netperf is a benchmark that can be used to measure the performance of a network. I did a simple test over a 1Gb/s ethernet link to compare IPv4 and IPv6 overhead, here are the results:

~ # netperf -4 -H MIGRATED TCP STREAM TEST from ( port 0 AF_INET to ( port […]