View Issue Details
|ID||Project||Category||View Status||Date Submitted||Last Update|
|0006893||Xen4||[CentOS-6] -OTHER||public||2014-01-10 12:57||2014-01-10 12:59|
|Product Version||[CentOS-6] 6.5|
|Target Version||[CentOS-6] 6.5||Fixed in Version|
|Summary||0006893: xen_balloon errors in syslog|
|Description||This mailing list thread discusses the issue:|
System RAM resource [mem 0xc8000000-0xcfffffff] cannot be added
xen_balloon: reserve_additional_memory: add_memory() failed: -17
|Tags||No tags attached.|
This from David Vrabel on the mail list:
Drivers (e.g., blkback) use ballooned pages for use for foreign
mappings. Depending on dom0_mem options there may be no ballooned
memory available at boot and dom0's balloon is increased by allocating
pages. This decreases current_kb.
The balloon driver then tries to decrease the balloon to match the
target but it can only do this by hotplugging new memory. A bug in the
balloon driver means the location of this memory overlaps with an
address range that is already in use and the hotplug will fail.
As a workaround you can boot dom0 with a suitable amount of
pre-ballooned memory with:
You may need to experiment with the max: value.
I would suggest that approx. 16 MB per VM is a reasonable amount of
e.g., dom0_mem=3G,max:4G would allow for approx. 64 VMs.