[dacrib.net]

I had read about the transparent compression that zfs offers. I wanted to verify it so I did, and sent my results off.

As we all know no experiment is valid unless verifiable. I wanted be sure that the transparent compression was actually working so I set up a sample zfs volume and purposefully made some files that i knew would compress really well. I grabbed their sizes, transferred them to another machine without zfs, and compared the size. It works.

1. Create the zfs filesystem
root@machine1:~# zfs create rpool/ztest
root@machine1:~# zfs set mountpoint=/ztest rpool/ztest

as soon as you do this /ztest shows up in the filesystem
root@machine1:~# ls /ztest/

2. enable compression and set it use gzip at level 6 (default)
root@machine1:/ztest# zfs set compression=gzip rpool/ztest

3. create some files you know will compress well
time for i in $(seq 1 3); do echo -n “file${i} “; echo $(seq 1 10000000) >> file${i} 2>&1; done

4. check the compression ratio
root@machine1:/ztest# zfs get compressratio rpool/ztest
NAME         PROPERTY       VALUE        SOURCE
rpool/ztest  compressratio  3.69x        -

5. verify the compression is working by transferring the file to a machine without such an awesome FS, and checking the filesize there
root@machine1:/ztest# du -sh file1
23M     file1
scp -rvp /ztest/file1 root@machine2:/root/file1

root@machine2]# du -sh file1
83M    file1

Conclusion: transparent compression is working, and working rather well on a file I made to be easily compressed.

I should have known about this for a while, but I recently learned that I could use seq to generate a sequence of numbers. It has options for doing things like only outputting even numbers in the generated sequences, and more. Great for used in bash loops.

I had forgotten how nice apt was in relation to yum. I mean yum is great, I could never build a package manager like rpm; let alone a utility as versatile and helpful as what yum is. I may have the capacity to build something that sucks right around the level of up2date 0.6.  I had managed to keep that machine running fedora for years, beginning with fedora core 2. I had never reinstalled, or performed fresh installs during that time, I just kept modifying the repos, running yum update, and fixing major issues as they came up. That machine has gone through a lot with me; but it has always been a dev machine. From my first install of Asterisk that I would later use to build Viatalk, to being my test machine while studying for the RHCE. I appreciate what the community has given me. Without open source software I wouldn’t be a system admin. I would never have found the interest. Maybe I would be a cop.
Ubuntu as a distro feels very by the people/ for the people. Things that I didn’t expect to work like playing mp3’s out of the box did with very little work on my end. I tried it for a day, and just went right back home. To fedora 9.