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. Regards, Daniel -- Fingerprint: BFB3 08D6 B4D1 31B2 72B9 29CE 6696 BF1B 14E6 1D37 Powered by Debian GNU/Linux Squeeze - Linux user #188.598
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