Daniel Bareiro wrote: > Hi Brian. > > On Tuesday, 08 September 2009 16:18:09 -0500, > Brian Jackson wrote: > > > > I'm trying to modify the amount of RAM that has some of guests. Host > > > has 2.6.30 kernel with KVM-88. > > > > > > In one of guest I didn't have problems when decreasing the amount of > > > memory from 3584 MIB to 1024 MiB. This guest has 2.6.26-2-686 stock > > > kernel. Also I was trying to decrease the amount RAM of another guest > > > from 3584 MiB to 2048 MiB, but it didn't work. This other guest has > > > 2.6.24-etchnhalf.1-686-bigmem stock kernel. Does Ballooning in guest > > > require 2.6.25 or superior? > > > I don't know, if that kernel has a virtio-balloon driver, I'd think that > > was all you need to balloon memory. > > Then can be that it is related to kernel that is using the guest: > > # uname -a > Linux aprender01 2.6.24-etchnhalf.1-686-bigmem #1 SMP Mon Jul 27 03:56:49 UTC > 2009 i686 GNU/Linux > > # cat config-2.6.24-etchnhalf.1-686-bigmem | grep -i virtio > # > > > > Thinking that it could be an impediment related to the kernel version > > > of guest, I tried to increase the memory of another one guest with > > > 2.6.26-2-686 from 512 MIB to 1024 MIB, but this didn't work either. > > > You can only grow memory up to the amount you specified on the command > > line if you've already ballooned down. > > Good. Thanks for clarifying to me this detail. > > > So if you specify "-m 1024M" on the command line, then shrink it to 512, > > you could then balloon it back up to a max of 1024. > > According to the tests that I was doing in guest with kernel with support > for virtio, shrinking works, but when trying to return to the amount of > initial memory, seems that it fails and I lose connectivity by serial > console and ssh. > > In the guest: > > # uname -a > Linux central 2.6.26-2-amd64 #1 SMP Sun Jul 26 20:35:48 UTC 2009 x86_64 > GNU/Linux > > # cat config-2.6.26-2-amd64 | grep -i virtio > CONFIG_NET_9P_VIRTIO=m > CONFIG_VIRTIO_BLK=m > CONFIG_VIRTIO_NET=m > CONFIG_HW_RANDOM_VIRTIO=m > CONFIG_VIRTIO=m > CONFIG_VIRTIO_RING=m > CONFIG_VIRTIO_PCI=m > CONFIG_VIRTIO_BALLOON=m > > In the host: > > # telnet localhost 4045 > Trying 127.0.0.1... > Connected to localhost. > Escape character is '^]'. > QEMU 0.10.50 monitor - type 'help' for more information > (qemu) > (qemu) info balloon > balloon: actual=512 > (qemu) balloon 256 > (qemu) info balloon > balloon: actual=256 > (qemu) > (qemu) balloon 512 > (qemu) info balloon > balloon: actual=36 > > At this moment I'm unable to connect by serial console to the guest and the > ssh sessions are freeze nevertheless kvm process of the guest is running. > Using a VNC client I see several messages of this type in the guest: > > Out of memory: kill process xxxx (<name>) score xx or a child > Killed process xxxx (<name>) > > Finally: > > Kernel panic - not syncing - Out of memory and no killable processes... > > > > Thanks for your reply.
Hi Daniel, I noticed no-one answered this, and I just ran into the same thing myself. As Avi pointed out earlier, it is a guest bug, and upgrading the guest to 2.6.27 should fix it: http://www.mail-archive.com/kvm@vger.kernel.org/msg10849.html -jim -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
