Normally to drop a database in PostgreSQL, we can just type: DROP DATABASE database; Here’s a list of my current databases: postgres=# \l List of databases Name | Owner | Encoding | Collate | Ctype | Access privileges -------------+-----------+----------+-------------+-------------+----------------------- dashboard | dashboard | UTF8 | en_US.UTF-8 | en_US.UTF-8 | postgres | postgres | UTF8 | en_US.UTF-8 | en_US.UTF-8 | postgres-db | postgres | UTF8 | en_US.UTF8 | en_US.UTF8 | puppetdb | puppetdb | UTF8 | en_US.UTF8 | en_US.UTF8 | template0 | postgres | UTF8 | en_US.UTF-8 | en_US.UTF-8 | =c/postgres + | | | | | postgres=CTc/postgres template1 | postgres | UTF8 | en_US.UTF-8 | en_US.UTF-8 | =c/postgres + | | | | | postgres=CTc/postgres (6 rows) I want to drop a database named postgres-db. So, let’s try to drop it: ...

As of today, the default storage for Docker on (K)Ubuntu 15.10 is AUFS. I want to switch it to OverlayFS. Personally, I’m still new to Docker, but I did hear that OverlayFS is better than AUFS. You can read more about OverlayFS here. Anyway, the purpose of this post is how to switch OverlayFS and avoid head-scratching. On Ubuntu 15.10 (wily), one can start/stop services either using Upstart or systemd. Since I want to get more accustomed to using systemd, I’ve been trying to use it anywhere possible. For example, here’s the command to start docker: ...

Well, first of all I think the title of this post won’t entirely reflect its content. However, I need to go ahead and post this now. At work, We’ve been having issues with cups service not running on some Kubuntu 14.04 desktops. This should not happen since even if cups service is dead, we have Puppet agent running on each machine to check and make sure that ‘cups’ is running else will be automatically restarted. ...

I’m running ZFS on Fedora 23 and I notice that there’re new features which can be enabled in the existing pool. # zpool status pool: tank state: ONLINE status: Some supported features are not enabled on the pool. The pool can still be used, but some features are unavailable. action: Enable all features using 'zpool upgrade'. Once this is done, the pool may no longer be accessible by software that does not support the features. See zpool-features(5) for details. scan: none requested config: NAME STATE READ WRITE CKSUM tank ONLINE 0 0 0 raidz1-0 ONLINE 0 0 0 sdb ONLINE 0 0 0 sdc ONLINE 0 0 0 errors: No known data errors Get the ZFS version for tank’s pool: ...

The RaspBSD image for Raspberry Pi can be found at http://raspbsd.org/raspberrypi.html. After it’s been downloaded, we need to copy it to a microSD card. Before we can do that, we need to find out the device name represents the microSD card. One way to find out is to plug the card in, and check the newest messages of dmesg. $ dmesg ... [282430.689656] mmc0: new SDHC card at address aaaa [282430.691039] mmcblk0: mmc0:aaaa SU08G 7.40 GiB [282430.711060] mmcblk0: p1 p2 In my case, using Ubuntu 15.10, the card is detected as mmcblk0. ...