Someone found my old ZFS snapshot script rather useful and wanted to improve it. Unfortunately I used the GPLv2 license in the original script. To accommodate my friend, I have re-released the snapshot script under the 2-clause BSD license. Feel free to use whichever license, 2-clause BSD or GPLv2, that suits your needs. Continue reading Periodic ZFS snapshots – 2-clause BSD license
clang is a breath of fresh air when it comes to deliver meaningful diagnostic of errors in program code. Not only is the diagnostic colourful on screen, clang also points out where in the source file changes ought to be made.
Someone named “Edward M” posted on the freebsd-questions mailing list a question of when should we create a ZFS filesystem. I didn’t reply to any of the messages, but I decided to write this post expressing my view.
In short, whenever a part of the filesystem hierarchy exhibits different characteristics, create one or more ZFS filesystems for that particular subtree. Continue reading When to create a ZFS filesystem?
A few days ago I resurrected all my files from a desktop system I haven’t used for almost six years. Below is my implementation of secret splitting as described in Bruce Schneier’s book “Applied Cryptography, 2nd edition”.
The idea is basically: generate a random keystream, xor the plaintext with the random keystream, use separate couriers and send the random keystream and the ciphertext to the final destination using separate routes, and finally combine the random keystream with the ciphertext to recreate the plaintext. None of the couriers know which piece they are carrying.
To improve this idea would be to generate more than one random keystream, xor the keystreams and the plaintext, thus requiring more couriers and different routes for each datastream.
And, by the way, xor crypto isn’t really that strong. Continue reading Secret splitting
Jeg børstet støvet av noen tilårskomne filer forleden dag. Jeg fant et lite program som jeg skrev en gang i 2000. Programmet teller ned til slutten av Unix-epoken.
Den opprinnelige definisjonen av datatypen
time_t, 32-bit heltall med fortegn, vil få overflyt i midten av januar 2038. Moderne 64-bit OS som FreeBSD/amd64 9.0 har for lengst gått over til 64-bit
time_t. Bare ta en titt i fila
/usr/src/sys/amd64/include/_types.h, omtrent ved linje 83. Problemet med overflyten i år 2038 vil fortsatt gjelde alt utstyr og (binære) filformater som bruker den gamle definisjonen, slik som FreeBSD/i386 9.0. Ta en titt i fila
/usr/src/sys/i386/include/_types.h, omtrent ved linje 91. Den engelske utgaven av Wikipedia har en utfyllende artikkel om problemet.
Kildekoden for det søte, lille programmet mitt, er gjengitt under. Continue reading endofepoch.c
If you trust your users well, you might feel slightly less anxious and allow your users to create new filesystems below their own home directories. Continue reading ZFS Delegated Administration in FreeBSD
Last year we had the World IPv6 Day on June 8, 2011. This year we’ll have the World IPv6 Launch on June 6, 2012.
According to this joint press release by Akamai Technologies, Inc., AT&T, Cisco, Comcast, D-Link, Facebook, Google Inc., Internet Society, Internode, Limelight Networks, Microsoft Bing, Time Warner Cable, and Yahoo!:
Major Internet service providers (ISPs), home networking equipment manufacturers, and web companies around the world are coming together to permanently enable IPv6 for their products and services by 6 June 2012.
The hard question is: Are you prepared? Continue reading Are you prepared for the World IPv6 Launch on June 6, 2012?
Every non-key attribute
must provide a fact about
the whole key,
and nothing but the key, so help me Codd.
From IRC@EFnet: 2012-04-12T11:34:56+0200 <@kim>
Here’s a conundrum aimed at those dabbling in the internals of Microsoft Windows 7. Continue reading Persisting IPv6 DNS resolver addresses
One of my systems is running FreeBSD/amd64 9.0-STABLE and is using ZFS for all its worth. The amount of installed memory in this system is 8 gibibytes, which should be enough to please even ZFS’ ARC. After a few hours of uptime not everyone are happy, and one of those unhappy guys are GnuPG. Continue reading Not enough room for wired pages?