http://bugzilla.xensource.com/bugzilla/show_bug.cgi?id=1260

Summary: xm mem-set domU shrinks memory of domU, but in dom0 it shrinks too Product: Xen Version: unstable Platform: x86-64 OS/Version: Linux Status: NEW Severity: normal Priority: P2 Component: Hypervisor AssignedTo: xen-...@lists.xensource.com ReportedBy: seba...@l00-bugdead-prods.de

I tried to shrink the memory of some domU's running, to get a bit free, to be able to start another one.

the the shell output when I tried to do this:

sre@it001:~> ssh ro...@srv2.srv.intern Password: Last login: Tue May 20 15:09:53 2008 from 192.168.8.30 srv2:~ # xm mem-set FTP 300 srv2:~ # vi /etc/xen/vm/OPP srv2:~ # xm list Name ID Mem VCPUs State Time(s) Domain-0 0 256 2 r----- 41224.9 ECOGNITION 2 100 1 -b---- 3888.2 FTP 12 300 1 -b---- 24185.2 OGo 24 1750 1 -b---- 6758.9 OPP 9 300 1 -b---- 59158.1 WWW 18 1200 1 -b---- 61672.0 srv2:~ # xm shutdown OPP srv2:~ # xm list Name ID Mem VCPUs State Time(s) Domain-0 0 256 2 r----- 41225.6 ECOGNITION 2 100 1 -b---- 3888.2 FTP 12 300 1 -b---- 24185.2 OGo 24 1750 1 -b---- 6759.3 OPP 9 300 1 r----- 59158.6 WWW 18 1200 1 ------ 61673.9 srv2:~ # xm list Name ID Mem VCPUs State Time(s) Domain-0 0 256 2 r----- 41226.1 ECOGNITION 2 100 1 -b---- 3888.2 FTP 12 300 1 -b---- 24185.3 OGo 24 1750 1 -b---- 6759.3 OPP 9 300 1 -b---- 59161.7 WWW 18 1200 1 -b---- 61674.3 srv2:~ # xm list Name ID Mem VCPUs State Time(s) Domain-0 0 256 2 r----- 41226.4 ECOGNITION 2 100 1 -b---- 3888.2 FTP 12 300 1 -b---- 24185.3 OGo 24 1750 1 -b---- 6759.3 OPP 9 300 1 -b---- 59162.2 WWW 18 1200 1 -b---- 61674.3 srv2:~ # xm list Name ID Mem VCPUs State Time(s) Domain-0 0 256 2 r----- 41227.4 ECOGNITION 2 100 1 -b---- 3888.3 FTP 12 300 1 -b---- 24185.3 OGo 24 1750 1 -b---- 6759.3 WWW 18 1200 1 -b---- 61674.3 srv2:~ # xm create /etc/xen/vm vm/ vm.old/ srv2:~ # xm create /etc/xen/vm vm/ vm.old/ srv2:~ # xm create /etc/xen/vm/OPP -c Using config file "/etc/xen/vm/OPP". Copy kernel /boot/vmlinuz-xen from xvda2 to /var/lib/xen/tmp/kernel.Fq2qBB for booting

srv2:~ # Error: Not enough free memory and dom0_min_mem is 0, so I cannot release any more. I need 410112 KiB but only have 307200.

srv2:~ # xm info host : srv2 release : 2.6.16.57-0.9-xen version : #1 SMP Mon Jan 21 19:55:27 UTC 2008 machine : x86_64 nr_cpus : 2 nr_nodes : 1 cores_per_socket : 2 threads_per_core : 1 cpu_mhz : 2205 hw_caps : 178bf3ff:e3d3fbff:00000000:00000010:00000001:00000000:00000002 total_memory : 3927 free_memory : 300 max_free_memory : 450 max_para_memory : 446 max_hvm_memory : 436 node_to_cpu : node0:0-1 xen_major : 3 xen_minor : 2 xen_extra : .0_16718_02-0.5 xen_caps : xen-3.0-x86_64 xen-3.0-x86_32p xen_scheduler : credit xen_pagesize : 4096 platform_params : virt_start=0xffff800000000000 xen_changeset : 16718 cc_compiler : gcc version 4.1.2 20070115 (prerelease) (SUSE Linux) cc_compile_by : abuild cc_compile_domain : suse.de cc_compile_date : Tue Jan 22 01:13:56 UTC 2008 xend_config_format : 4 srv2:~ # xm list Name ID Mem VCPUs State Time(s) Domain-0 0 256 2 r----- 41231.7 ECOGNITION 2 100 1 -b---- 3888.4 FTP 12 300 1 -b---- 24185.4 OGo 24 1750 1 -b---- 6759.4 WWW 18 1200 1 -b---- 61674.3 srv2:~ # xm mem-set ECOGNITION 80 srv2:~ # xm mem-set OGo 1700 srv2:~ # xm mem-set WWW 1170 srv2:~ # xm create /etc/xen/vm/OPP -c Using config file "/etc/xen/vm/OPP". Error: Not enough free memory and dom0_min_mem is 0, so I cannot release any more. I need 410112 KiB but only have 286720. srv2:~ # xm list Name ID Mem VCPUs State Time(s) Domain-0 0 256 2 r----- 41234.8 ECOGNITION 2 80 1 -b---- 3888.7 FTP 12 300 1 -b---- 24185.7 OGo 24 1700 1 -b---- 6762.5 WWW 18 1170 1 -b---- 61682.1 srv2:~ # xm info host : srv2 release : 2.6.16.57-0.9-xen version : #1 SMP Mon Jan 21 19:55:27 UTC 2008 machine : x86_64 nr_cpus : 2 nr_nodes : 1 cores_per_socket : 2 threads_per_core : 1 cpu_mhz : 2205 hw_caps : 178bf3ff:e3d3fbff:00000000:00000010:00000001:00000000:00000002 total_memory : 3927 free_memory : 280 max_free_memory : 430 max_para_memory : 426 max_hvm_memory : 417 node_to_cpu : node0:0-1 xen_major : 3 xen_minor : 2 xen_extra : .0_16718_02-0.5 xen_caps : xen-3.0-x86_64 xen-3.0-x86_32p xen_scheduler : credit xen_pagesize : 4096 platform_params : virt_start=0xffff800000000000 xen_changeset : 16718 cc_compiler : gcc version 4.1.2 20070115 (prerelease) (SUSE Linux) cc_compile_by : abuild cc_compile_domain : suse.de cc_compile_date : Tue Jan 22 01:13:56 UTC 2008 xend_config_format : 4 srv2:~ # srv2:~ # srv2:~ # xm list Name ID Mem VCPUs State Time(s) Domain-0 0 256 2 r----- 41242.5 ECOGNITION 2 80 1 -b---- 3889.0 FTP 12 300 1 -b---- 24185.9 OGo 24 1700 1 -b---- 6766.4 WWW 18 1170 1 -b---- 61705.8

as you can see in the output of xm info, the free memory is not raising.

The solution was to reboot the dom0. After that, then everything was fine again.

The system is SLES10SP1, x86_64. The installed xen is xen 3.2.0 from the SP2.

rpm -qa | grep -i xen xen-doc-pdf-3.2.0_16718_02-0.5 xen-3.2.0_16718_02-0.5 kernel-xen-2.6.16.57-0.9 xen-kmp-smp-3.2.0_16718_02_2.6.16.57_0.9-0.5 xen-libs-3.2.0_16718_02-0.5 xen-tools-3.2.0_16718_02-0.5 xen-tools-ioemu-3.2.0_16718_02-0.5