As I've mentioned here before, I have a Linksys NSLU2 that I use as a home server. These ship with an embedded Linux system in their firmware, but they can be upgraded to run a full Debian system, making them much more capable. Mine has been running Debian 4.0 (Etch) since I got it.

A couple of days ago I ssh'ed into it to perform a regular software update. apt-get upgrade installed a new kernel, as it has several times before. So I rebooted it. And it failed to boot back into Linux. Since these things don't have any video hardware to reveal the details of the boot process, I've no idea what the problem was.

I interpreted this as a sign that it was time for an upgrade to Debian 5.0 (Lenny).

What I found impressive, considering the constraints and increasing age of the NLSU2, is that it is better supported in Lenny than it was in Etch. The Lenny installation is done using the normal Debian installer (you ssh into it). There's really not much more to it than installing Debian on a PC, though it is a lot slower (about four hours, apparently; I left it going overnight).

There's another noteworthy thing about it: Unlike Etch, Lenny for ARM comes with a recent 2.6.26 kernel with CONFIG_NOHZ enabled. And here is the vmstat output:

dwragg@bb5a:~$ vmstat 1
procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----
 r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa
 0  0   9060   1572    628  18004    0    0    20     8   18   63  0  0 99  0
 0  0   9060   1572    628  18004    0    0     0     0   18    6  0  0 100  0
 0  0   9060   1572    628  18004    0    0     0     0   16    8  0  0 100  0
 0  0   9060   1572    628  18004    0    0     0     0   17    8  0  0 100  0
 0  0   9060   1572    628  18004    0    0     0     0   18   12  0  0 100  0
 0  0   9060   1572    628  18004    0    0     0     0   16    7  0  0 100  0
 0  0   9060   1572    628  18004    0    0     0     0   17    5  1  0 99  0
 0  0   9060   1572    628  18004    0    0     0     0   18    9  0  0 100  0
 0  0   9060   1572    628  18004    0    0     0     0   19   13  0  0 100  0

Check out the in and cs values!

If, under Fedora, you install a kernel update, and it refuses to boot with the error above, then it is probably this bug. Apparently, it's fixed in rawhide. And if we're very lucky, they might even push the fix out for F10.

Further to my last post, I note that Mathematica has released Mathematica Home Edition, for $295. It's the full Mathematica, but for personal use only. And I'm glad to see that the Linux version is included.

The hitch is that it's only available in the US and Canada.

If this offer was available in the UK, I'd be tempted. My other issues with Mathematica still stand, but the high price is no longer so much of a barrier.

Update: The Home Edition offer is now available in the UK, at a price of £195.