Category: computer
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Don’t Upgrade vCenter Server Appliance From 5.0 to 5.1
Thinking of upgrading your vCenter Server Appliance from a 5.0 image to the 5.1 image using the official VMware upgrade process covered in the documentation? Don’t do it. It fails somehow. Every time. Unexpected error during the upgrade process. To attempt to upgrade again, restore the old vCenter Server Appliance and external database from backup/snapshot,…
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Vudu Disc-To-Digital Review
For those of you that just received this promo email… I decided to give it a try with stack of old DVDs. The promo pricing is totally reasonable, but I doubt it’ll last. (50% off when you “convert” 10+ discs, then $2 off your total.) Your existing DVD/BD titles are $2 to convert, or $5…
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Capistrano Hanging During .tgz Upload
I just spent an annoying amount of time troubleshooting a new cap-based deploy.rb for a Rails app to a new CentOS 6.4 server. The deploy.rb worked perfectly on other systems, but something about the configuration was causing `cap deploy’ to hang during the following: servers: [“myapp.example.com”] ** sftp upload /var/folders/0j/vmvt2by53m901wtmfv8xfjw40000gn/T/20130530225953.tar.gz -> /tmp/20130530225953.tar.gz Long story short,…
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Keeping Multiple Development Machines Synchronized with Homeboy
Most of us developer types have at least two machines we use routinely, and managing that can be a chore. Specifically, I usually want to do the following every time I sit down at a machine to hack on something: Keep config files like .bash_profile and .gitconfig synchronized. (This requires scripting since Dropbox ignores hidden…
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Ubuntu 12.10 to 13.04 Server Upgrade Error
Are you Googl’ing around trying to figure out why you’re getting this error when trying to `do-release-upgrade’ your Ubuntu 12.10 system, even though you’re pretty much up to date? root@mia:~# do-release-upgrade Checking for a new Ubuntu release Traceback (most recent call last): File “/usr/bin/do-release-upgrade”, line 145, in <module> fetcher.run_options += [“–mode=%s” % options.mode, AttributeError: type…
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Proxy Authentication Against Devise-Based Ruby Applications
(Quick GitHub link!) My team at TGen has a Rails application using a typical devise + cancan installation for authentication and authorization, respectively, and a related Apache HTTPD proxy server we needed to authenticate against active accounts in the webapp before passing traffic to their destination, which is a single host. We tried mod_authn_dbd for a…
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How To Custom Brand The OpenStack “Horizon” Dashboard
I’m deploying OpenStack “Essex” on Ubuntu Server 12.04, and have the openstack-dashboard package installed to provide the web-based “Horizon” GUI component newly added for the Essex release. Canonical also provides an openstack-dashboard-ubuntu-theme package that brands the Python-based Django GUI. Despite that the last major Canonical-maintained packages based on the OpenStack “Diablo” release in Ubuntu 11.10…
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OpenStack Nova Essex MySQL Database Schema Diagram and SQL
I’m in the process of setting up an OpenStack Essex installation on a small cluster of Ubuntu 12.04 servers using the Canonical-supplied and supported packages. I innocently and unfortunately ended up with a state corruption issue causing nova-compute to crash on startup, and found it necessary to dive into the schema as a troubleshooting aid.…
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OpenStack Diablo on Ubuntu 11.10 w/MySQL
If you’re installing the OpenStack cloud computing platform “Diablo” release on Ubuntu 11.10 server using the official guide and are using MySQL, don’t forget to: sudo apt-get install python-mysqldb The “glance” package (and probably others) are configured to use SQLite by default and do not automatically install this dependency by default. Unfortunately, the November 2011 version of the…
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Quick FASTQ File Parsing Via Memory Mapping In C/C++
I recently had a need to speedily parse through 8GiB+ .fastq text files to calculate a simple statistic of genomic data. My initial “pfastqcount” implementation in Ruby worked fine, but with many files to process took longer than I had hoped in addition to consuming an alarming amount of CPU. I ended up reimplementing the pfastqcount…