Category: Technology

How to fix “fstrim: Operation not supported” under KVM?

February 6th, 2014, 9 Comments

Maybe someone out there will have some ideas. I have a KVM host running wheezy, with wheezy-backports versions of libvirt and qemu. I have defined a guest, properly set discard=unmap in the domain XML file for it, verified that’s being passed to the guest, but TRIM/DISCARD is just not working. Mounting the ext4 filesystem with […]

Why and how to run ZFS on Linux

January 23rd, 2014, 15 Comments

I’m writing a bit about ZFS these days, and I thought I’d write a bit about why I am using it, why it might or might not be interesting for you, and what you might do about it. ZFS Features and Background ZFS is not just a filesystem in the traditional sense, though you can […]

Debian-Live Rescue image with ZFS On Linux; Ditched btrfs

January 22nd, 2014, 10 Comments

I’m a geek. I enjoy playing with different filesystems, version control systems, and, well, for that matter, radios. I have lately started to worry about the risks of silent data corruption, and as such, looked to switch my personal systems to either ZFS or btrfs, both of which offer built-in checksumming of all data and […]

Results with btrfs and zfs

December 7th, 2013, 20 Comments

The recent news that openSUSE considers btrfs safe for users prompted me to consider using it. And indeed I did. I was already familiar with zfs, so considered this a good opportunity to experiment with btrfs. btrfs makes an intriguing filesystem for all sorts of workloads. The benefits of btrfs and zfs are well-documented elsewhere. […]

Why are we still backing up to hardlink farms?

October 12th, 2013, 8 Comments

A person can find all sorts of implementations of backups using hardlink trees to save space for incrementals. Some of them are fairly rudimentary, using rsync –link-dest. Others, like BackupPC, are more sophisticated, doing file-level dedup to a storage pool indexed by a hash. While these are fairly space-efficient, they are really inefficient in other […]

Kindergarten Computer Class and Password Security

August 29th, 2012, 4 Comments

Jacob started Kindergarten last week. More on that in another post. He’s been loving it, until yesterday. At least part of his disgruntlement was because it was his first visit to computer class. Putting together a few conversations, we learned this: Jacob: Something was different about Kindergarten today. Us: Oh? What was it? Jacob: I […]

Voice Keying with bash, sox, and aplay

August 24th, 2012, No Comments

There are plenty of times where it is nice to have Linux transmit things out a radio. One obvious example is the digital communication modes, where software acts as a sort of modem. A prominent example of this in Debian is fldigi. Sometimes, it is nice to transmit voice instead of a digital signal. This […]

A Verbose, Hands-On Nexus 7 Review

August 11th, 2012, 14 Comments

Some of you may have noticed that I am not a concise author. Perhaps that has something to do with the fact that I am not a concise reader. I like facts, details, and lots of them. So as a recent Nexus 7 purchaser, here you go. Genesis I’ve long used Android devices, and last […]

How to get started programming?

July 28th, 2012, 10 Comments

I have been asked for advice from several people recently on how to get started programming, or how to further develop a nascent interest in coding or software engineering. The people asking the questions range in age from about 10 years old to older than me. These are people that, for various reasons, are not […]

A Linux-Based RFID Thing Finder

July 19th, 2012, 20 Comments

Sometimes I have things nicely organized. Power adapters for radios in one drawer, for cameras in the next. And sometimes… not so much. Sometimes I’m not sure if things are in the basement or the attic. It seems like technology should be able to help solve this problem, but as far as I can tell, […]

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