Marek Mahut » sysadmin http://marek.mahut.sk/blog Tue, 06 Jul 2010 14:46:09 +0000 http://wordpress.org/?v=2.9.2 en hourly 1 Linux Developers and Users Conference 2009 in Brno http://marek.mahut.sk/blog/2009/07/01/linux-developers-and-users-conference-2009-in-brno/ http://marek.mahut.sk/blog/2009/07/01/linux-developers-and-users-conference-2009-in-brno/#comments Wed, 01 Jul 2009 11:17:57 +0000 marek http://marek.mahut.sk/blog/?p=358 Red Hat Czech announced an open conference in Brno for all open source developers and users (yeah, sysadmins are also users). The list of presentations and workshops is growing and I already found some interested topics I’m looking forward to attend. Bookmark the link to its wiki page, more information will follow shortly.

developer-conference-brno

https://fedoraproject.org/wiki/DeveloperConference2009

]]> http://marek.mahut.sk/blog/2009/07/01/linux-developers-and-users-conference-2009-in-brno/feed/ 2 How to disable USB Disk STANDBY mode http://marek.mahut.sk/blog/2009/03/03/how-to-disable-usb-disk-standby-mode/ http://marek.mahut.sk/blog/2009/03/03/how-to-disable-usb-disk-standby-mode/#comments Tue, 03 Mar 2009 19:06:34 +0000 marek http://marek.mahut.sk/blog/?p=339 Recently I bought an external USB Disk Seagate FreeAgent XTreme, but after some idle time, it spanned down. Take me a while to find out how to disable this standby mode. First install sdparm.

If you want to start the drive in standby:

sdparm –command=start /dev/sdb

To clean standby mode flag:

sdparm –clear STANDBY -6 /dev/sdb && sdparm -a /dev/sdb

]]> http://marek.mahut.sk/blog/2009/03/03/how-to-disable-usb-disk-standby-mode/feed/ 3 VMware announces open source vmware viewer http://marek.mahut.sk/blog/2009/02/03/vmware-announces-open-source-vmware-viewer/ http://marek.mahut.sk/blog/2009/02/03/vmware-announces-open-source-vmware-viewer/#comments Tue, 03 Feb 2009 18:32:02 +0000 marek http://marek.mahut.sk/blog/?p=337 Wow! Even VMware understood the power of open source, they just announced open souce vmware client. Who will get it first into Fedora? ;)

]]> http://marek.mahut.sk/blog/2009/02/03/vmware-announces-open-source-vmware-viewer/feed/ 3 How to fix wrong dns serial number? http://marek.mahut.sk/blog/2009/01/06/how-to-fix-wrong-dns-serial-number/ http://marek.mahut.sk/blog/2009/01/06/how-to-fix-wrong-dns-serial-number/#comments Tue, 06 Jan 2009 14:57:07 +0000 marek http://marek.mahut.sk/blog/?p=305 Did it ever happen to you by mistake to add one additional digit into dns serial number? Ooops! Now, how to fix it?

  1. Increase the serial number to (2^31) – (correct serial number) and reload named. For example 2^31-2009010602 = 138473046. As DNS serial numbers are signed integers, this make server thinks that it’s a negative number.
  2. Set the serial number to 0 and reload.
  3. Set the correct serial number and reload.
  4. Voila!
]]> http://marek.mahut.sk/blog/2009/01/06/how-to-fix-wrong-dns-serial-number/feed/ 2 Linux distros’ homepage uptime http://marek.mahut.sk/blog/2008/11/20/linux-distros-homepage-uptime/ http://marek.mahut.sk/blog/2008/11/20/linux-distros-homepage-uptime/#comments Thu, 20 Nov 2008 09:44:35 +0000 marek http://marek.mahut.sk/blog/?p=259 Interesting report from pingdom about uptime of Linux ditros’ homepage (but also Apple and Microsoft). I’m more than happy to see Fedora and Red Hat taking leading positions in this benchmark.

]]> http://marek.mahut.sk/blog/2008/11/20/linux-distros-homepage-uptime/feed/ 1 Multiple host names in a single kerberos key tab http://marek.mahut.sk/blog/2008/11/19/multiple-host-names-in-a-single-kerberos-key-tab/ http://marek.mahut.sk/blog/2008/11/19/multiple-host-names-in-a-single-kerberos-key-tab/#comments Wed, 19 Nov 2008 12:33:55 +0000 marek http://marek.mahut.sk/blog/?p=253 If you are using clustered service with kerberos, you may want to merge hostnames keytab files to one for simple distribution.

  • Create host and service principals.
kadmin:  addprinc -randkey host/node1.corp.intranet.lan
kadmin:  addprinc -randkey host/node2.corp.intranet.lan
kadmin:  addprinc -randkey host/node3.corp.intranet.lan
kadmin:  addprinc -randkey host/node4.corp.intranet.lan
kadmin:  addprinc -randkey host/node5.corp.intranet.lan
kadmin:  addprinc -randkey host/node6.corp.intranet.lan
kadmin:  addprinc -randkey host/node7.corp.intranet.lan
kadmin:  addprinc -randkey host/node8.corp.intranet.lan
kadmin:  addprinc -randkey HTTP/node1.corp.intranet.lan
kadmin:  addprinc -randkey HTTP/node2.corp.intranet.lan
kadmin:  addprinc -randkey HTTP/node3.corp.intranet.lan
kadmin:  addprinc -randkey HTTP/node4.corp.intranet.lan
kadmin:  addprinc -randkey HTTP/node5.corp.intranet.lan
kadmin:  addprinc -randkey HTTP/node6.corp.intranet.lan
kadmin:  addprinc -randkey HTTP/node7.corp.intranet.lan
kadmin:  addprinc -randkey HTTP/node8.corp.intranet.lan

  • Save them to only one file (cluster.keytab).
kadmin:  ktadd -k /etc/httpd/cluster.keytab host/node1.corp.intranet.lan
kadmin:  ktadd -k /etc/httpd/cluster.keytab host/node2.corp.intranet.lan
kadmin:  ktadd -k /etc/httpd/cluster.keytab host/node3.corp.intranet.lan
kadmin:  ktadd -k /etc/httpd/cluster.keytab host/node4.corp.intranet.lan
kadmin:  ktadd -k /etc/httpd/cluster.keytab host/node5.corp.intranet.lan
kadmin:  ktadd -k /etc/httpd/cluster.keytab host/node6.corp.intranet.lan
kadmin:  ktadd -k /etc/httpd/cluster.keytab host/node7.corp.intranet.lan
kadmin:  ktadd -k /etc/httpd/cluster.keytab host/node8.corp.intranet.lan
kadmin:  ktadd -k /etc/httpd/cluster.keytab HTTP/node1.corp.intranet.lan
kadmin:  ktadd -k /etc/httpd/cluster.keytab HTTP/node2.corp.intranet.lan
kadmin:  ktadd -k /etc/httpd/cluster.keytab HTTP/node3.corp.intranet.lan
kadmin:  ktadd -k /etc/httpd/cluster.keytab HTTP/node4.corp.intranet.lan
kadmin:  ktadd -k /etc/httpd/cluster.keytab HTTP/node5.corp.intranet.lan
kadmin:  ktadd -k /etc/httpd/cluster.keytab HTTP/node6.corp.intranet.lan
kadmin:  ktadd -k /etc/httpd/cluster.keytab HTTP/node7.corp.intranet.lan
kadmin:  ktadd -k /etc/httpd/cluster.keytab HTTP/node8.corp.intranet.lan

  • As alternative, you can use command ktutil if you already have a bunch of keytab files.
ktutil:  rkt /etc/krb5/node1.corp.intranet.lan.keytab
ktutil:  rkt /etc/krb5/node2.corp.intranet.lan.keytab
ktutil:  rkt /etc/krb5/node3.corp.intranet.lan.keytab
ktutil:  rkt /etc/krb5/node4.corp.intranet.lan.keytab
ktutil:  rkt /etc/krb5/node5.corp.intranet.lan.keytab
ktutil:  rkt /etc/krb5/node6.corp.intranet.lan.keytab
ktutil:  rkt /etc/krb5/node7.corp.intranet.lan.keytab
ktutil:  wkt /etc/cluster.keytab

Voila.

]]> http://marek.mahut.sk/blog/2008/11/19/multiple-host-names-in-a-single-kerberos-key-tab/feed/ 1 Fedora infrastructure Puppet training http://marek.mahut.sk/blog/2008/09/20/fedora-infrastructure-puppet-training/ http://marek.mahut.sk/blog/2008/09/20/fedora-infrastructure-puppet-training/#comments Sat, 20 Sep 2008 08:34:29 +0000 marek http://marek.mahut.sk/blog/?p=178 Mike McGrath, the Fedora infrastructure lead, made an awesome presentation on puppet and how to use it. Slides and audio record are posted at http://mmcgrath.fedorapeople.org/puppet/.

]]> http://marek.mahut.sk/blog/2008/09/20/fedora-infrastructure-puppet-training/feed/ 1 Sysadmin’s monday blues: clean your RPMs http://marek.mahut.sk/blog/2008/07/14/sysadmins-monday-blues-clean-your-rpms/ http://marek.mahut.sk/blog/2008/07/14/sysadmins-monday-blues-clean-your-rpms/#comments Mon, 14 Jul 2008 20:50:42 +0000 marek http://marek.mahut.sk/blog/?p=115 From time to time, I need to clean my disk from useless stuff I’ve installed over time. It’s just amazing how much of packages I can install during debugging and configuring every day. If I’m short of disk space, I start first by reviewing biggest packages on my system:

[mmahut@mmahut repo]$ rpm -qa --queryformat '%10{size} %{name}-%{version}\n' | sort -k1,1nr | head
317673868 fgfs-base-0.9.11
215271762 openoffice.org-core-2.3.0
133572466 frysk-0.4
120848879 fpc-2.2.0
89947314 glibc-common-2.7
80722817 java-1.7.0-icedtea-1.7.0.0
65310309 emacs-common-22.1
61516077 googleearth-4.2.198.2451
61036768 inkscape-0.46
60173188 tetex-fonts-3.0
[mmahut@mmahut repo]$

Another useful program is package-cleanup from package yum-utils. You can use it to list duplicates, orphans or problematic packages as well as old kernel packages.

[mmahut@mmahut ~]$ package-cleanup --orphans | head
Setting up yum
cinelerra-2.1-0.14.svn20071111.kwizart.fc8.i386
desktop-file-utils-0.15-2.fc8.i386
NetworkManager-0.7.0-0.6.7.svn3370.fc8.i386
bind-utils-9.5.0-27.rc1.fc8.i386
PackageKit-libs-0.1.5-0.351.20071126git.fc7.hughsie.i386
redmode-1.0-1.fc8.i386
kurso-3.0-1.fc8.i386
x11vnc-0.9.3-2.fc8.i386
popt-debuginfo-1.13-1.fc8.i386
[mmahut@mmahut ~]$

I’ve cleaned up 200MB today, great success!

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