Over the weekend I was confronted by the above error being repeated on the console of a VM running Oracle RDBMS.
This error occurs when there is a shortage of CPU resources. For me the solution was a quick shut down of the VM and increasing the available CPU resources. However there are more ways to skin this cat…
There is also a kernel parameter which can be tweaked;
Were “x” is the threshold (in seconds) you want to allow the kernel to wait before decided there has been a soft lockup.
The Red Hat documentation showed a threshold of 30 seconds. So I would recommend a bit of experimentation if you feel that 30 seconds is not high enough. Or throw more resources at it.
Featured image: The Old Lockup was made available by John Powell on Flickr.
Following on from an earlier post, it would seem that the “Warning /dev/root does not exist” issue is not confined to “none” kickstart pxe booted installations as I had first thought.
I was working on a RHEL 7 installation using Red Hat Satellite 5.7 (upgrade to 6.x in the pipeline but bigger fish to fry right now), where we were re-using a lot of the RHEL 6 pxelinux kernel parameter’s.
Now as you may or may not know (if you have read my other posts on the topic), there are numerous Anaconda and dracut parameter’s that can be passed to the kernel in the pxelinux.cfg/default (or the mac specific) config file. The problem we had found was the existence off a ksdevice= parameter which pointed to eth0. In RHEL/CentOS 7, the ethernet device naming standard changes from ethX to ensX, which works out as follows;
- en = Ethernet
- sX = Slot X (where X is the physical or virtual slot number where the nic resides)
By default the first interface is used by anaconda/dracut/pxelinux, IF no option is specified. If however you specifically tell it to use something which fundamentally doesn’t exist, it WILL still try to use that… and fail! Miserably! And give you an error which ultimately seems kind of unrelated.
You have been warned!
As with many things in life, this served as a reminder that things change and that you can’t always take the “old” and reuse with the “new” without issue.
Featured image credit: Thanks to (Elba) Dave Shewmaker for taking the rather weird picture which resembles The Devil in the Detail and posting it on Flickr.