Marek Mahut » rhel

Linux Developers and Users Conference 2009 in Brno

marek — Wed, 01 Jul 2009 11:17:57 +0000

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.

https://fedoraproject.org/wiki/DeveloperConference2009

Red Hat Czech Open House

marek — Tue, 07 Apr 2009 18:04:44 +0000

Red Hat Czech invites you to Open House event in Brno. Come and see how enterprise open source software is build – be a part of it! :)

How to disable USB Disk STANDBY mode

marek — Tue, 03 Mar 2009 19:06:34 +0000

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

How to fix wrong dns serial number?

marek — Tue, 06 Jan 2009 14:57:07 +0000

Did it ever happen to you by mistake to add one additional digit into dns serial number? Ooops! Now, how to fix it?

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.
Set the serial number to 0 and reload.
Set the correct serial number and reload.
Voila!

The open road: Red Hat “deeply undervalued,” Oracle Linux “has failed”

marek — Fri, 05 Dec 2008 08:56:14 +0000

I find Matt Asay’s new article about Mark Murphy’s analyzes on Oracle enterprise linux very interesting, quoting part of the article.

Oracle has failed in its attempt to enter the Linux market. Our recent survey of Oracle database customers reveals that only 1 out of 32 customers currently uses Oracle Unbreakable Linux. This one customer also commented that “support is terrible, it is difficult to get an answer to my problems, Oracle’s agents never understand my company.” The survey reflects a very low penetration rate in the 2-year period since Oracle unveiled Unbreakable Linux with much fanfare, including live penguins running around onstage with Larry Ellison. Resellers continue to characterize Unbreakable Linuxas a failure because Oracle ultimately cannot control the future direction of RedHat Enterprise Linux, upon which it is based.

While the Street has expected Unbreakable Linux to severely impact Red Hat, its failure ironically serves as a proof-point of the underlying defensibility of RedHat’s business model. In fact, in the two years since Oracle introduced Unbreakable Linux, Red Hat’s billings have grown at an average rate of 31%–representing clear market share gains.

Linux distros’ homepage uptime

marek — Thu, 20 Nov 2008 09:44:35 +0000

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.

Multiple host names in a single kerberos key tab

marek — Wed, 19 Nov 2008 12:33:55 +0000

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.