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Oracle® VM Server for SPARC 3.6 Administration Guide

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Updated: September 2019
 
 

Resource Management Issues

Removing a Large Number of CPUs From a Domain Might Fail

You might see the following error message when you attempt to remove a large number of CPUs from a guest domain:

Request to remove cpu(s) sent, but no valid response received
VCPU(s) will remain allocated to the domain, but might
not be available to the guest OS
Resource modification failed

To avoid this issue, remove fewer than 100 CPUs at a time from the domain.

Sometimes a Block of Dynamically Added Memory Can Be Dynamically Removed Only as a Whole

Due to the way in which the Oracle Solaris OS handles the metadata for managing dynamically added memory, you might later be able to remove only the entire block of memory that was previously dynamically added rather than a proper subset of that memory.

This situation could occur if a domain with a small memory size is dynamically grown to a much larger size, as shown in the following example.

primary# ldm list ldom1
NAME  STATE FLAGS   CONS VCPU MEMORY UTIL UPTIME
ldom1 active -n--   5000 2    2G     0.4% 23h

primary# ldm add-mem 16G ldom1

primary# ldm remove-mem 8G ldom1
Memory removal failed because all of the memory is in use.

primary# ldm remove-mem 16G ldom1

primary# ldm list ldom1
NAME  STATE FLAGS   CONS VCPU MEMORY UTIL UPTIME
ldom1 active -n--   5000 2    2G     0.4% 23h

To work around this issue, use the ldm add-mem command to sequentially add memory in smaller chunks rather than in chunks larger than you might want to remove in the future.

    If you have experienced this problem, perform one of the following actions:

  • Stop the domain, remove the memory, and then restart the domain.

  • Reboot the domain, which causes the Oracle Solaris OS to reallocate its memory management metadata such that the previously added memory can now be removed dynamically in smaller chunks.