Oracle VM for Sparc Autosave / Practical case

Have ever faced a situation where you think you've lost LDOMs configuration (mostly after an unexpected downtime)? If that's the case, then you must know how much autosave feature on Oracle VM for SPARC is important. Indeed, the main aim of the autosave feature is to ensure that a copy of the current configuration is automatically saved on the control domain whenever the Logical Domains configuration is changed. More important, it occurs even when the new configuration is not explicitly saved on the SP.

Note that this doesn't replace the classic LDOMs configuration Backup which consists of saving the constraints information for each domain into an XML file (ldm list-constraints -x...), but may supplement it when what is needed is just to recover domain Configurations that weren't saved to the SP. 

Enough talk! Let's move forward with this practical case. We've a System with 05 configured LDOMs, and while building them, an unexpected Hardware Failure occurs (:-)). The main issue is that we haven't saved yet our LDOM Configuration on the SP. Meaning before the Outage, we had something similar to:

root@scdomain:~# ldm ls-spconfig factory-default initial [next poweron] root@scdomain:~# ldm ls NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- UART 16 32G 6.9% 12h 21m STEVELDOM01 active -n---- 5000 16 32G 0.0% 10h 17m STEVELDOM02 active -n---- 5001 16 32G 1.0% 10h 52m STEVELDOM03 active -n---- 5002 16 32G 0.1% 10h 52m STEVELDOM04 active -n---- 5003 16 32G 0.1% 10h 52m STEVELDOM05 active -n---- 5004 16 32G 9.9% 10h 51m

And after the outage, we've something like this (with maybe some other parameters not present for the primary domain...).

root@scdomain:~# ldm ls-spconfig factory-default initial [next poweron] root@scdomain:~# ldm ls NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- UART 16 32G 6.9% 10m

Let's move forward with the following 05 little steps to recover our LDOMs configuration.

1. As a matter of precaution, take a Backup of the actual configuration and another one of the /var/opt/SUNWldm

The /var/opt/SUNWldm folder contains the Autosave directories.

root@scdomain:~# ldm list-constraints -x > /export/home/admin/backup_faulty.xml root@scdomain:~# tar cvf /export/home/admin/sunwldom.tar /var/opt/SUNWldm


2.lists the available autosave configurations

At this stage, we should have our autosaved configuration shown as being newer than the current configuration.

root@scdomain:~# ldm ls-spconfig -r initial [newer]

3. Recover the Autosave Configuration

root@scdomain:~# ldm add-spconfig -r initial


4. Perform a full power Cycle

root@scdomain:~# shutdown -y -g0 -i5 -> start /SYS Are you sure you want to start /SYS (y/n)? y Starting /SYS

5. Check the LDOM Configuration 

root@scdomain:~# ldm ls-spconfig factory-default initial [next poweron] root@scdomain:~# ldm ls NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- UART 16 32G 6.9% 12h 21m STEVELDOM01 active -n---- 5000 16 32G 0.0% 10h 17m STEVELDOM02 active -n---- 5001 16 32G 1.0% 10h 52m STEVELDOM03 active -n---- 5002 16 32G 0.1% 10h 52m STEVELDOM04 active -n---- 5003 16 32G 0.1% 10h 52m STEVELDOM05 active -n---- 5004 16 32G 9.9% 10h 51m

References:

http://docs.oracle.com/cd/E19604-01/821-0406/configurationmanagement/index.html