Lenz Grimmer's blog

I just published the second part of a blog post series about Linux Containers on the OTN Garage blog (where a lot of my recent blogging takes place nowadays) — check it out if you would like to get an introduction and some quick examples on how to get started with this technology on Oracle Linux (and other Linux distributions that support Linux Containers, of course):

• Linux-Containers — Part 1: Overview
• Linux Container (LXC) — Part 2: Working With Containers

German versions of these articles are also available from the OLIVI_DE - Oracle LInux und VIrtualisierung blog:

• Linux-Container (LXC) — Teil 1: Überblick
• Linux Container (LXC) — Teil 2: Arbeiten mit Containern

We also recorded a short whiteboard session about this topic a while ago — the video is available from the Oracle Linux YouTube channel: Linux Containers Explained

It took me several attempts, but this blog is finally reachable via both http://www.lenzg.net/ and http://www.lenzg.org/ directly again. I had some trouble migrating the .org domain name to my new hosting company, but it's finally done. So now lenzg.org is no longer doing a http redirect, but will serve these pages directly!

Now I only need to get back to blogging more often here - a lot of my writing activity is currently done elsewhere...

Last week we concluded our first Oracle Technology Network Sys Admin Day in Sacramento (CA). Well, it was actually the second Sys Admin Day, but the first one that had two parallel tracks of sessions about both Oracle Linux and Oracle Solaris.

I helped preparing for the event by creating the Linux lab handbook as well as the VirtualBox appliance of Oracle Linux 6.1 that was used for the exercises. Unfortunately I could not be there in person, but it would have been pointless for me to go on an intercontinental flight just for one day.

From the feedback we've received so far, the attendees really enjoyed the event and were positively surprised about the depth and quality of the practical hands-on lab sessions.

If you've missed the first one and happen to live somewhere in the Seattle area, you have another chance to attend OTN sysadmin day: we'll be hosting another one on Thursday, September 22nd at The Westin Seattle (1900 5th Ave., Seattle, WA 98101). Again, attendance is free, all you need to bring is your own laptop with VirtualBox installed. We'll provide the rest. Space is limited — you can review the agenda and register here!

• On Tuesday, May 03, 2011, 8:00am to 4:00 pm, there will be the OTN Developer Day for MySQL in the Oracle Santa Clara Agnews Campus Auditorium. It will cover application development with MySQL, performance tuning tips and managing MySQL environments.
• On Tuesday, May 17, 2011, 8:00 am to 4:00 pm, the OTN's first Sys Admin Day for Oracle Solaris will take place in the Hyatt Regency La Jolla at Aventine in San Diego, CA. Topics include ZFS, security and virtualization using Solaris zones.

I tend to switch between Linux and OpenSolaris as my desktop operating system from time to time. To be more flexible in this setup, I store most of my work-related data (e.g. source trees, VirtualBox images) on an external 320GB USB disk drive, using the ZFS file system. While OpenSolaris supports ZFS natively, I can access the file system on Linux using zfs-fuse and I could even mount these file systems on a FreeBSD system, if needed. There aren't that many file systems that allow an easy exchange of data between (Open)Solaris and Linux – the other ones that I am aware of are FAT and UFS, which both don't give me the confidence and flexibility I need.

A while ago, I purchased a second external drive of the same size and now use both of them in a mirrored configuration. This gives me several benefits:

• Redundancy: external disk drives have a higher risk of getting physically damaged, so having a mirrored copy of my data ensures that I won't lose anything important if one of the drives dies.
• Increased performance: ZFS is capable of distributing reads across both devices, thus I get twice the speed of a single USB 2.0 port, if I connect the drives to ports attached to separate USB host controllers.
• Automatic resyncing: When I'm on the road, I only take one half of the mirror with me. In case this drive gets lost/stolen, I still have a second copy of the data at home. ZFS complains about the pool being in degraded state, but continues to work normally. When I return home, I simply attach the second drive again and ZFS automatically resyncs (resilvers) anything that has been modified in the meanwhile.
• I can use snapshots for backup purposes. I have a small Intel Atom based PC (running OpenSolaris) that acts as my central file server (using two 1TB disks in a ZFS mirror) and CUPS print server. If I want to create a backup of my external USB disks, I create ZFS snapshots of the file systems in question and transfer these to the home server using "zfs send/receive". This works both locally by connecting the drives to the server box directly or via SSH over the network. I wrote a small shell script to automate this process. The transfer is done in an incremental fashion – only the differences between the current and the last snapshot are being propagated. To save disk space on the external drives, I usually discard all older snapshots except for the last one or two. On the file server, I maintain snapshots for a longer time period. The snapshots are named by using a simple date/time timestamp (filesystem@YYYY-MM-DD-HH:MM), this makes it easy to go back to a particular snapshot in case I'm looking for something I may have removed by accident, but I still recall when it was last used.

From my experience, ZFS is a very solid and reliable solution, providing impressive functionality with a very user-friendly UI (you only need use two commands, zfs and zpool).

If you want to learn more about ZFS and how to use it in practice, consider attending my upcoming talk (in German) about this subject at FrOSCon 2010 in Sankt Augustin, Germany!

I'm happy to announce that my talk "Making MySQL administration a breeze - a look into a MySQL DBA's toolchest" has been accepted for this year's edition of the MySQL Conference & Expo in Santa Clara, which will take place on April 12-15, 2010. The session is currently scheduled for Wednesday 14th, 10:50 in Ballroom E.

My plan is to provide an overview over the most popular utilities and applications that a MySQL DBA should be aware of to make his life easier. The focus will be on Linux/Unix applications available under opensource licenses that ease tasks related to user administration, setting up and administering replication setups, performing backups and security audits.

Of course I will cover the usual suspects (e.g. Maatkit), some of these are actually collections of different utilities by themselves. As it's impossible to go over each individual component in the given time frame, I will try to pick out the most popular/useful parts related to the scopes mentioned above. But I will also cover some lesser known gems that migh be worth taking a look at. What's your the most valued tool in your toolchest? I am still looking for more inspiration.

I look forward to being at the conference again and meeting with colleagues and friends in the MySQL community. Judging from the current schedule, it will be a very interesting mix of talks.

If you're interested in attending, you should consider registering soon! The early registration ends on March 15th. Until then, I encourage you to make use of this "Friend of Speaker" discount code (25% off): mys10fsp