Archive for the ‘Linux’ Category

Red Hat Enterprise Linux 6 is out!

Back to blogging in honor of RHEL 6…

Finally, the latest major version of RHEL is announced today.

Here is the press release for it: and the release notes are available at

More importantly all the new stuff can be found here:

There are a lot of improvements and new features all of which I think will make Red Hat Linux a rock solid operating system for the data center.

Ubuntu 9.10 released

The awaited Ubuntu version 9.10 aka Karmic Koala is released today.

It is available for download here.

Some of the notable changes are:

  • Linux kernel 2.6.31
  • GNOME 2.28
  • Mozilla Firefox 3.5
  • 3.1.1
  • Empathy Instant Messenger replacing Pidgin for instant messaging tasks
  • Ubuntu One client for the Ubuntu One, personal cloud platform that provides 2GB of storage to keep you files, notes and contacts
  • Ubuntu Software Center is the new graphical utility for package management which replaces the traditional GNOME Add/Remove tool

Also there are some important feature changes like:

  • ext4 is the new default filesystem used for new installations
  • GRUB2 is the new default boot loader for new installations
  • Upstart is the new startup mechanism that replaces the venerable System-V init

These features seem to  help achieve faster boot times.

The Ubuntu variants Kubuntu, Xubuntu, Edubuntu, Mythbuntu, and Ubuntu Studio are also updated to version 9.10

Release Notes contains a list of known problems with this new release but there is no show stopper so far.

See here for some screenshots.

ASMLIB createdisk problem on emcpower devices — solved

If you are using ASMLIB library to label ASM disks on Red Hat Enterprise Linux 5.X or SuSE Linux Enterprise Server 10/11 systems with EMC PowerPath as your multipathing software you may encounter the following error while running the oracleasm createdisk command:

#/etc/init.d/oracleasm createdisk DATA01 /dev/emcpowera1
Marking disk "/dev/emcpowera1" as an ASM disk:
asmtool: Device "/dev/emcpowera1" is not a partition

This is due to the EMC PowerPath bug #285242 which makes  it to not properly support the sd_getgeo() i/o calls that oracleasm makes, as mentioned in the Oracle Metalink document 469163.1 and EMC Powerlink document emc203137

The workaround to overcome this problem is to use the asmtool command with “-a force=yes” option.

#/usr/sbin/asmtool -C -l /dev/oracleasm -n DATA01 -s /dev/emcpowera1 -a force=yes
asmtool: Device "/dev/emcpowera1" is not a partition
asmtool: Continuing anyway

asmtool will also complain that the device is not a partition but it will put the asmlib header on the device and create the related device file under /dev/oracleasm/disks/ directory. However it will leave the device file with root:root as the owner and group. Restarting the asmlib service will solve this problem.

service oracleasm restart

The actual solution has arrived with PowerPath for LINUX 5.3.1 for RHEL and PowerPath for LINUX 5.3.2 for SLES 11. After updating to this release oracleasm createdisk command works flawlesly as expected.

#oracleasm createdisk DATA02 /dev/emcpowerb1
Writing disk header: done
Instantiating disk: done

There are some other very important bugs solved in Powerpath releases 5.3 and 5.3 SP1 like “Dynamic addition of large number of LUNs may result in a host hang” and “PowerPath: emcpmgr processes are causing high load during startup” so there is good reason to update to the latest Powerpath release.