Monthly Archives: August 2012

Btrfs – Linux answer to ZFS

Sadly ZFS on Linux is not at the same maturity level than on FreeBSD (or even Solaris). There is a FUSE implementation but it is now more than 16 month since anything happen there, and in my opinion not yet stable. Regarding native ZFS port, only one ZFS implementation for Linux is still developed by the Lawrence Livermore National Laboratory but it is still a release candidate version.
The state of ZFS on Linux is perhaps not too good today, but there is another file system in development and good support that could soon compete with ZFS, its name is btrfs (pronounce ‘butter-fs‘). Btrfs is still experimental
Yesterday, one of my virtual machines running Oracle Linux 6.3 got its root file system full, as it was configured with LVM it was not so much trouble but I wanted to try btrfs. I decided to move the /var to another partitions using btrfs. I have created a new hard disk in my VM and started it. Here is the rest of the story.

Warning: following these instructions might break your system. As an advice, create a virtual machine and experience with it before doing so on a real system.

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SSH goodies

Today I stumble upon an article regarding SSH on Oracle’s blogs.

One interesting feature I did not know is the SSH escape character ‘~’. So many times I had to open another terminal just to do one command locally before returning to the SSH session. Now this is over, just type ~^Z (a tilde followed by Ctrl-Z). Example

malmur :: ~ » uname -a
FreeBSD malmur 9.0-RELEASE-p3 FreeBSD 9.0-RELEASE-p3 #0: [...]
malmur :: ~ » ssh 192.168.78.10
unbreakable :: ~ » uname -a
Linux unbreakable.linux 2.6.39-200.29.1.el6uek.x86_64 #1 [...]
unbreakable :: ~ » ~^Z [suspend ssh]
[1]  + 2540 suspended  ssh 192.168.78.10
malmur :: ~ » fg
[1]  + 2540 continued  ssh 192.168.78.10
unbreakable :: ~ »