On my new netbook
I wanted to get rid of gdm and
just start X right away. I use auto-login anyway so it
is a bit stupid to first start gdm and then immediately start X.
So I removed gdm and edited /etc/rc.local to start X:
su - miekg -c xinit xterm
But this sort of does not work anymore in Ubuntu Karmic. Karmic
now uses upstart as an init replacement.
So I figured why
not write an upstart job that starts X?
I’ve bought a new 11.1" netbook from Asus, this is going to replace my aging 4G Surf (named charm). I’ve named the new one up, so I’m hoping the Large Hadron Collider is up and running soon and discovers a new flavor of quarks - ‘cause I’m running out of names. (strange is already allocated if I ever buy a Mac and run Linux on that, top and bottom just don’t sound right).
Okay, I could not find this in the specs, but I do find this fishy. When querying a Windows DNS server it will give out an authoritative answer (aa bit set), but without an AUTHORITY section.
dig +nocmd +noidentify +multiline @ns5.msft.net. soa hotmail.com
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
;; WARNING: recursion requested but not available
;; QUESTION SECTION:
;hotmail.com. IN SOA
;; ANSWER SECTION:
hotmail.com. 86400 IN SOA ns1.msft.net. msnhst.microsoft.com. (
2009100802 ; serial
1800 ; refresh (30 minutes)
900 ; retry (15 minutes)
2419200 ; expire (4 weeks)
3600 ; minimum (1 hour)
)
;; ADDITIONAL SECTION:
ns1.msft.net. 3600 IN A 65.55.37.62
And it gets worse:
iotop is a very neat tool showing the processes which do the most
i/o in a top-like manner.
Again having fun with SLES:
SLES-10:
# rpm -i /tmp/iotop-0.3.2-1.1.x86_64.rpm
warning: iotop-0.3.2-1.1.x86_64.rpm: Header V3 DSA signature: NOKEY, key ID ee454f98
error: Failed dependencies:
python >= 2.5 is needed by iotop-0.3.2-1.1.x86_64
Goes off and installs SLES-11
SLES-11:
# rpm -i
warning: /tmp/iotop-0.3.2-1.1.x86_64.rpm: Header V3 DSA signature: NOKEY, key ID ee454f98
error: Failed dependencies:
python < 2.6 is needed by iotop-0.3.2-1.1.x86_64
Nooooo!
An unofficial rpm of e2fsprogs installed on a SLES 10 system:
# ldd /sbin/e2fsck
libdb-4.3.so => /usr/lib64/libdb-4.3.so (0x00002b5e004e2000)
libpthread.so.0 => /lib64/libpthread.so.0 (0x00002b5e006d6000)
libc.so.6 => /lib64/libc.so.6 (0x00002b5e007ef000)
/lib64/ld-linux-x86-64.so.2 (0x00002b5e003c6000)
Now guess what happens when you reboot?
The nss-ldap module allows you to have your user information
in a LDAP server. Within the module you can select some
options on how to connect to the LDAP server:
hard, use an exponential back-off when connection, waiting
up to 64 seconds before trying a different server.soft, when the server is not responding give up immediately.The problem is, both are insufficient…
With soft you don’t have any benefits for your backup LDAP server.
With the hard policy you can failover to the second (or third) server,
but when you boot the machine (and it does not have networking) you are
stuck with the exponential back-off. This can mean that booting a server
can take a couple of hours: every uid lookup will take 64 seconds.
Heb PSP gekocht. Wow! Eindelijk weer leuk gamen.
Well, as I’m off to The Hague for the rest of the year, I need some kind of Internet in the evening. So off to KPN to get a umts card (or dongel as they call it). For late night gaming I’ve also bought a PSP :-)
Well, to make a long story short: this stuff is hard to get working in Ubuntu. When you insert the dongle it is first seen as a cdrom…, only after you successfully install the Windows software it will become a modem. Who comes up with this kind of crap?
After trying out Zabbix, I’m back to
munin and monit for my (small) monitoring needs.
I think the beautiful rrd images of munin are just unbeatable and
monit has never let me down; you can easily restart daemons -
something I was still configuring in zabbix. And
our
Ubuntu Certified Professional Course
also has a few slides on munin. This was the last push I needed.
I was still a bit rusty so I just followed a howto to do the initial configuration.
Well, a lets-install-kernel-2.6.31-on-Ubuntu-Jaunty turned out to be a bad idea. The kernel install went OK, but my X went poef. No more bitmap fonts. Looks like some bad interaction between the X Intel driver and the new kernel mode settings.
Anyhow, I figured why not upgrade to Karmic? 15 minutes later my desktop system was completely hosed and I was left staring at a GRUB 1.97 menu.
I never knew that the GRUB command line allows you to type
With monit services are restarted, ever since I’ve installed zabbix I
wanted the same functionallity. Turns out this is possible, but it
takes some configuration.
Also see the zabbix manual, where it gets interesting from page 160 onwards.
In zabbix go to Configuration->Actions.
Add a new ‘Action Operation’ in which you want to run a remote command.
elektron:/home/miekg/bin/zabbix_service {TRIGGER.NAME}: {STATUS}And zabbix_service is now a shell script which will echo its
arguments to a file in /tmp.
The shell (in this case bash) is packed with features. So much so that
you will probably never ever learn them all. Brace expansion is one of
those things.
What is it? In the bash manual it says:
Brace Expansion
Brace expansion is a mechanism by which arbitrary strings may be generated. This mechanism is similar to pathname expansion, but the filenames generated need not exist
So what is it? You can make your shell generate strings, like so:
Just bought anothor EeePC, this time the 900HD variant. Installing Ubuntu as we speak and giving Windows the boot. The 4 minute encounter with Windows XP (which felt like 4 hours) gave me the impression of a fast machine. This was just a quick peek to see if the hardware was working.
Going with Ubuntu 9.04 - then removing Pulseadio and (maybe) upgrading the kernel to 2.6.30.4.
The trick is to disable the hardisk in the BIOS and to disable all quick boot stuff in there too. So that my SD card with the Ubuntu install will boot.
Excellent idea Ton!
How to make a custom filter in git to expand the string $Hash$ to
something more usefull, ala the $Id$ (which git already supports), but
then with more info (committer, date, etc.).
Which also helped in this case was the Pro Git book which is, as of now, a must buy.
But as always is the case between Ton and me, I find his scripts too long :-) So I miekified his solution.
In Perl you have this:
% perl -e 'print "a" x 5, "\n"'
aaaaa
With that you can easily create a separator string consisting out of 60 spaces.
I always missed this in my shell - until now.
In Zsh have the following expansion:
l:expr::string1::string2:
Pad the resulting words on the left. Each word will be truncated if required and placed in a field expr characters wide.
See zsh.dotsrc.org.
There is also a r: variant which operates in the same way.
While rechecking my rdup test-suite one of the tests failed. On closer inspection it was due to the following line:
DAY_BEFORE=$(( $(date +%d) - 1 ))
When $(date +%d) is 10 this yields:
$ DAY_BEFORE=$(( 10 - 1 ))
$ echo $DAY_BEFORE
9
Also with octal values (those starting with a leading zero), it also works:
$ DAY_BEFORE=$(( 06 - 1 ))
$ echo $DAY_BEFORE
5
So when does this go wrong? When the day is 08 or 09 (as it is
today):
A customer wanted some performance figures for a ESX cluster we built. We used our own atop and the trusted workhorse of plotting Gnuplot to make some performance plots.
As said, we used atop for this, it has a nice data gathering
mode which prints out lines like these:
13:40:07 cpu %usr %nice %sys %irq %softirq %steal %wait %idle
13:40:08 all 0 0 0 0 1 0 4 95
13:40:09 all 0 0 1 0 0 0 0 99
We were interested in the values of %usr, %sys, %irq + %softirq,
%wait and %idle.
So you think you know git… today I found out something “funny”. In a git repository:
$ git log
$ fatal: object 1fcc8de9361c56e538ff35d8cc4b07a9c95b7bf3 is corrupted
Okay, WTF? Lets look in the .git directory:
$ cd .git/objects/1f
$ ls -l
total 4
-r--r--r-- 1 root root 1057 2009-06-23 19:03 03db070bcb47bff3f8106f2ec7028b3496aaa8
-r--r--r-- 1 root root 0 2009-08-03 21:41 cc8de9361c56e538ff35d8cc4b07a9c95b7bf3
Ah, 0 bytes, that explains it (probably due to the weird reboot of last night and ext4).
Finally made the switch to jackd which works so much better than
Pulseaudio. Ubuntu did not make this easy, but with some perseverance
it works. One of the things I really hate about Pulseaudio is that
when I click on a new song in audacious it would take about 1 second
before the audio stabilized. Also with flash audio would stutter for the
first few seconds.
First (if you don’t care about gnome-desktop):
Yes, what a nice post on ssh escape keys.
So you need to press <enter> and then ~ for the escape character to
work!
If you ever administered a DNS server you are probably familiar with the IN
(internet) class, as in
localhost IN A 127.0.0.1
where you define an IP address for the name localhost. As you may, or
may not, already know there are other classes defined (but hardly used) for
the DNS. Two of those are the Chaos class (CH) and the Hesiod (HS)
class. With these classes you can create some sort of parallel world
where you can also define names. This feature of the DNS isn’t exactly
in great use, but is is nice to know where they were used for.
google wave ref impl. is in java... *yech*
Do I want this?
% ls -ld Joe_Cocker_-_The_Definitive_Collection
drwxr-xr-x 2 miekg admin 4.0K Jul 20 22:20 Joe_Cocker_-_The_Definitive_Collection/
% cd *joe*
cd: no such file or directory: *joe*
% unsetop case_glob
% cd *joe*
% pwd
/shared/vol/music/J/Joe_Cocker_-_The_Definitive_Collection
Currently we are building a fairly rock solid high availability cluster for a client. This has the “usual” ingredients: two locations, two NetApps, two clusters of three vmware ESX servers and a bunch of virtual machines running on top of the ESX servers. Also included in the mix is a VDI (now called View) virtual desktop infrastructure for running virtual windows XP clients.
This is all managed by SRM (site recovery manager) and it is almost working. But that is another story.
I’ve told a few times about how to build a library.
But there a some extra things that must be done before you can call yourself a complete librarian.
For this I bought a barcode reader that reads the ISBN number
of the book’s backcover. With book_get
(Perl code)
I can retrieve the author, title, genre and year published from Google.
I already knew (Open)Solaris sucks, but now Ton has also figured it out.
ZFS definitely does not suck. Why not petition Oracle to GPL(v2) ZFS? Especially now Oracle wants to kill OpenSolaris?
So, there I am browsing my logs.
BAM
[650521.310292] INFO: task mysqld:2730 blocked for more than 120 seconds.
[650521.310320] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[650521.310364] mysqld D 00000000 0 2730 2674
[650521.310367] f6183ce0 00000086 c06ef6cc 00000000 f61c8c70 7834922a 00000dc2 00020050
[650521.310373] 00000296 c0796fe0 c0796fe0 f61c8f04 c2c35fe0 00000003 9500b16e 00024f83
[650521.310379] 00000002 00000002 f66bb500 f6d02e40 c2bf2090 f6e2e680 f6183ce8 c050eb68
[650521.310384] Call Trace:
[650521.310388] [<c050eb68>] schedule+0x8/0x20
[650521.310391] [<c0266701>] do_get_write_access+0x2a1/0x3d0
[650521.310395] [<c0127d93>] ? kmap_atomic_prot+0x43/0xe0
[650521.310398] [<c0150030>] ? wake_bit_function+0x0/0x60
[650521.310402] [<c02669a3>] jbd2_journal_get_write_access+0x23/0x40
[650521.310405] [<c0252a36>] __ext4_journal_get_write_access+0x26/0x60
[650521.310409] [<c023e9d4>] ext4_reserve_inode_write+0x34/0x70
[650521.310413] [<c023ea45>] ext4_mark_inode_dirty+0x35/0x140
[650521.310416] [<c02669ac>] ? jbd2_journal_get_write_access+0x2c/0x40
[650521.310420] [<c02446cf>] add_dirent_to_buf+0x12f/0x340
[650521.310423] [<c0245032>] ext4_add_entry+0xe2/0x1d0
[650521.310427] [<c024540a>] ext4_add_nondir+0x1a/0x70
[650521.310430] [<c0245814>] ext4_create+0xc4/0x100
[650521.310434] [<c01d0ced>] vfs_create+0xcd/0x170
[650521.310437] [<c01d2562>] __open_namei_create+0x42/0xa0
[650521.310441] [<c01d2be0>] do_filp_open+0x620/0x660
[650521.310444] [<c01ca888>] ? cp_new_stat64+0xe8/0x100
[650521.310448] [<c02d3a67>] ? strncpy_from_user+0x37/0x60
[650521.310451] [<c01c52a1>] do_sys_open+0x51/0xe0
[650521.310455] [<c01c5399>] sys_open+0x29/0x40
[650521.310458] [<c0102ebc>] sysenter_do_call+0x12/0x28
Okay, what the hell…Two questions.
Yes! At work today we made dhcpd crash on a /etc/dhcpd.conf :) We
were working towards the following (now working) setup:
class "igel" {
match if binary-to-ascii(16, 8, "-", substring (hardware, 0, 5)) = "1-0-e0-c5-67";
}
pool {
allow members of "igel";
range 192.84.30.161 192.84.30.170; # igel[0-9]
}
But while figuring this out, dhcpd went boom :)
[root@vmaster cfengine]# dhcpd -d -f -cf hosts/vnet/etc/dhcpd.conf
Internet Systems Consortium DHCP Server V3.0.5-RedHat
Copyright 2004-2006 Internet Systems Consortium.
All rights reserved.
For info, please visit http://www.isc.org/sw/dhcp/
hosts/vnet/etc/dhcpd.conf line 20: can't override match.
match if
^
hosts/vnet/etc/dhcpd.conf line 22: pool declared outside of network pool
^
Segmentation fault
I wanted to pretty print my labels on my (new) Dymo 400 label writer. All the howtos I found were detailing how to use LaTeX to print a sheet of labels. But I needed some LaTeX-foo to print only one. So /me to the rescue…
My labels are 36mm X 89 mm (Dymo part #99012) after some trial and error and four misprinted labels I came to the following LaTeX code which fits the text on the labels: