Archive for August, 2009

Checksum for multi-gigabyte filesystem images ?

I’m currently looking for a (very) fast way to (more or less reliably) checksum multi-gigabyte filesystem images (namely VMFS), to validate that my somehow compressed image files, once expanded, are still accurate to what the original image used to be. One of the main features of the image files is that they are sparse files, so you’d get bonus points with checksum algorithms that allow fast addition of a huge amount of zeroes.

So far, I’ve considered Adler-32, Fletcher-32, though I’m unsure how they would accurately detect the kind of bogus output I could get, and also “md5 of md5” or “sha-1 of sha-1” (i.e. calculate the md5 or sha-1 sum of the concatenation of the md5 or sha-1 sums of blocks of some size, where you can pre-calculate the md5 or sha-1 sums for blocks full of zeroes).

Dear lazyweb, do you have any better ideas, before I start looking more seriously at the ideas above?

2009-08-26 23:34:38+0900

vmfs-tools | 8 Comments »

Re: Debian Start

Adnan, for some reason, your post that is present on planet debian doesn’t appear on your blog at the moment (Sorry, no posts matched your criteria.). I would have commented there if that were possible. Anyways, I will give my opinion here, with different hats on.

(User hat on) The idea to have a similar start page on the different browsers is a nice idea.

(Web designed hat on) Some implementation details on your mockup are discussable, most notably the design in pixels (which doesn’t help for the vision impaired needing big fonts), the list of fonts to be used, and the border being part of the background image. Also, considering the targetted browsers, SVG could be a nice addition.

(Iceweasel, Xulrunner and WebKit maintainer hat on) The content at the bottom suggests the page is intended to be put online somewhere. Browsers start page shouldn’t require an internet connexion. There should also be space for browser-specific icon and text. I’d really like to keep specific links, such as to bug reports and README.Debian (though the latter should really be htmlized). Speaking of these links, another one should be added some day in the future, to provide a link to a page explaining how users can help the maintainers (thanks to whoever came up with this idea during my BoF at DebConf).

2009-08-25 20:24:42+0900

firefox, webkit, xulrunner | 5 Comments »