Category Archives: Mathematics

Administrative, Mathematics, Technology and Society

Weird Linux Problem

13 Comments

Anyone have any ideas why I can’t do a yum update in Fedora? Or rather, why I can’t write to the disk as root?

# yum update
Loaded plugins: langpacks, refresh-packagekit
Cannot open logfile /var/log/yum.log
Repository google-chrome is listed more than once in the configuration

[Errno 30] Read-only file system: ‘/var/cache/yum/x86_64/20/adobe-linux-x86_64/repomd.xml.old.tmp’

Here’s what I’m seeing at /:

# ls -l
total 65
lrwxrwxrwx. 1 root root 7 Dec 11 2013 bin -> usr/bin
dr-xr-xr-x. 6 root root 4096 Dec 22 14:47 boot
drwxr-xr-x. 21 root root 3520 Dec 24 09:15 dev
drwxr-xr-x. 140 root root 12288 Dec 24 09:15 etc
drwxr-xr-x. 4 root root 4096 Dec 20 2013 home
lrwxrwxrwx. 1 root root 7 Dec 11 2013 lib -> usr/lib
lrwxrwxrwx. 1 root root 9 Dec 11 2013 lib64 -> usr/lib64
drwx——. 2 root root 16384 Dec 11 2013 lost+found
drwxr-xr-x. 2 root root 4096 Nov 7 16:53 media
drwxr-xr-x. 3 root root 4096 Dec 20 2013 mnt
drwxr-xr-x. 4 root root 4096 Oct 29 15:18 opt
dr-xr-xr-x. 222 root root 0 Dec 24 09:14 proc
dr-xr-x—. 12 root root 4096 Dec 22 15:33 root
drwxr-xr-x. 34 root root 900 Dec 24 09:17 run
lrwxrwxrwx. 1 root root 8 Dec 11 2013 sbin -> usr/sbin
drwxr-xr-x. 2 root root 4096 Aug 7 2013 srv
dr-xr-xr-x. 13 root root 0 Dec 24 09:14 sys
drwxrwxrwt. 12 root root 280 Dec 24 09:21 tmp
drwxr-xr-x. 12 root root 4096 Dec 11 2013 usr
drwxr-xr-x. 21 root root 4096 Dec 24 09:14 var

Here’s /var:

# ls -l /var
total 112
drwxr-xr-x. 2 root root 4096 Dec 11 2013 account
drwxr-xr-x. 2 root root 4096 Aug 7 2013 adm
drwxr-xr-x. 14 root root 4096 Dec 20 2013 cache
drwxr-xr-x. 2 root root 4096 Aug 5 21:27 crash
drwxr-xr-x. 2 root root 4096 Aug 2 2013 cvs
drwxr-xr-x. 3 root root 4096 Oct 2 09:32 db
drwxr-xr-x. 3 root root 4096 Dec 11 2013 empty
drwxr-xr-x. 2 root root 4096 Aug 7 2013 games
drwxr-xr-x. 2 root root 4096 Aug 7 2013 gopher
drwxr-xr-x. 3 root root 4096 Aug 7 17:19 kerberos
drwxr-xr-x. 46 root root 4096 Dec 24 09:14 lib
drwxr-xr-x. 2 root root 4096 Aug 7 2013 local
lrwxrwxrwx. 1 root root 11 Dec 11 2013 lock -> ../run/lock
drwxr-xr-x. 15 root root 4096 Dec 24 09:15 log
lrwxrwxrwx. 1 root root 10 Dec 11 2013 mail -> spool/mail
drwxr-xr-x. 2 root root 4096 Aug 7 2013 nis
drwxr-xr-x. 2 root root 4096 Aug 7 2013 opt
drwxr-xr-x. 2 root root 4096 Aug 7 2013 preserve
lrwxrwxrwx. 1 root root 6 Dec 11 2013 run -> ../run
drwxr-xr-x. 10 root root 4096 Dec 11 2013 spool
drwxrwxrwt. 539 root root 36864 Dec 24 09:15 tmp
drwxr-xr-x. 2 root root 4096 Aug 7 2013 yp

I tried to just create a file in /root, with no success (though that’s not really surprising, given the permissions). What’s really weird is that I have no problems writing as a normal user. It’s just a problem with root. Which is, of course, a big problem. I’ve tried rebooting, with no joy.

[Later afternoon update]

OK, I’ve gotten the machine beaten into submission. I loaded Fedora 21 on a live USB, and (unlike Fedora 20) it will actually boot with my new motherboard. So I cleaned up the drives, then installed the new OS on the new SSD. I overmounted my old /home drive onto the new /home, and I’m reinstalling software, which is going very fast, because the SSD is very fast. With the new quad-core processor, I’m cooking with Crisco. Nice Christmas present to myself.

[Update a few minutes later]

Wow. Just did a reboot after a bunch of updates. Ten seconds.

Business, Economics, Health, Mathematics, Media Criticism, Political Commentary

The Fatal Conceit

25 Comments

…of Jonathan Gruber:

The Times reassuringly described Gruber as “the numbers wizard at MIT,” who has “spent decades modeling the intricacies of the health care ecosystem.” Gruber has “brought a level of science to an issue that would otherwise be just opinion.”

I might note that the Soviets used the term “science” for their own “scientific” planning commission. I drew little comfort from Professor Gruber’s scientific-planning credentials, especially when I learned “he’s the only person you can go to for that kind of thing.” Gruber, aided by his brilliant MIT graduate student assistants, is a one-man Gosplan, the name given to the Soviet Union’s state planning committee. That is not much of a recommendation. Science is better served by competing ideas not by a one-person monopoly.

Both Gruber and the USSR’s Gosplan planners believe their planning is “scientific” and executed by “the best of the best.” Both types of planning commissars suffer from F. A. Hayek’s “fatal conceit”—the belief that we can plan incredibly complex economic systems. As Hayek pointed out in his writings, such “scientific” plans inevitably fall apart under the weight of unintended consequences.

Actually, I’m not sure they’re all unintended.