Posts tagged Dell

Debugging VMware vSphere host profiles


Last weeks I’ve built a new VMware vSphere 5.1 cluster based on diskless Dell M710HD blades. When creating a host-profile to push configurations to all members (servers) of the cluster to keep consistency I’ve noticed two out of 16 blades did not comply with the created profile, showing these error messages:

  • Host state doesn’t match specification: device mpx.vmhbaXX parameters need to be reset
  • Host state doesn’t match specification: device mpx.vmhbaXX Path Selection Policy needs to be set to default for claiming SATP

Googling around brought me to VMware KB2002488 but unfortunately this didn’t solve the compliance issue either. Debugging further and comparing a compliant and non-compliant server brought me to the Dell iDRAC-interface. The non-compliant server had the virtual media drive (forced) attached. To solve this issue, log in via iDRAC, select the Virtual Console/Media tab, sub Configuration and choose Auto-attach in the Virtual Media drop down menu. Now rescan the host profile and your server should be compliant.

iDRAC virtual media causes problems with VMware host profiles compliance

iDRAC virtual media causes problems with host profiles compliance

Where is eth0 on new Dell servers


Dell made some changes in their 12th generation servers like the R520, R620, R720, etc. These changes reflect Consistent Network Device Naming announced by the Fedora project earlier. Onboard network interfaces are no longer know as eth0, eth1, etc. by default but now named em1, em2, etc.

System Administrators can then use BIOS-provided names, which are consistent and not arbitrarily named, for their network ports. This eliminates the confusion that non-deterministic naming brings, and eliminates the use of hard-coded MAC address based port renaming which a) is racy and error-prone, and b) introduces state into an otherwise stateless system.

But there can be some problems. What if you use licensed software that used the MAC-address as unique identifier and polls hard to /dev/eth0. Well, then you have to hack around in the boot parameters of grub to use the old ethX device naming. This is also the case if you’re current PXE of Configuration Management isn’t ready for the new device naming.

  1. cp –preserve=context /etc/grub.conf /etc/grub.bak
  2. Add biosdevname=0 to the kernel boot arguments in /etc/grub.conf.
  3. Rename /etc/sysconfig/network-scripts/ifcfg-em1 to /etc/sysconfig/network-scripts/ifcfg-eth0, changing the line DEVICE=”em1″ to DEVICE=”eth0″
  4. Delete /etc/udev/rules.d/70-persistent-net.rules
  5. Reboot.

Now the network devices have their old names again. I’ve tested this with CentOS 6.2. If you’re looking for a quick fix for your current PXE-environment just use the first two steps (Add biosdevname=0 to the kernel boot arguments in /etc/grub.conf).

Dell DSET 3.2 on CentOS 6


We have been having some issues with some Dell servers and we were asked to provide a DSET output for one of them. Of course the new version 3.2 does not run directly under CentOS 6.x, however as RHEL is supported then it should work. This is the steps I took to get it to work:

mkdir -p /tmp/dell; cd /tmp; wget

This binary does a lot of checking to see that it is to be run on a supported system, unfortunately CentOS is not one of them. So I extracted the contents using:

tail -n+20 dell-dset- | tar -xzv -C dell; cd dell

The +20 offset was found by using:

awk '/^__ARCHIVE_BELOW__/ {print NR + 1; exit 0; }' dell-dset-

You will need to find the RedHat strings for /etc/issue and /etc/redhat-release, once changed. After that, run ./ and select install and run. The easiest way to do so is adding this line on top of your /etc/issue:

Red Hat Enterprise Linux Server release 6 x86_64

Dell: Since CentOS is should be 100% binary compatible with Redhat, please provide support. It’s your department always asking for DSET reports. Provide us, SysAdmins, the good tools to do this without waisting a lot of time.

If you find the above method to scary, just use an older version of the DSET tool. This one isn’t strict on checking the OS type:

By the way: Is the Dell website hosted on the moon. Sloooooowww as always.

Dell certification


Thanks for your signature Michael!

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