Norman Gaywood
2011-Jun-28 23:41 UTC
[CentOS-virt] More than 32G on memory in a domU guest?
I must be missing something obvious. I have a large domU guest: dom0# cat /etc/xen/turing name = "turing" uuid = "8d3383a0-f0ae-f0b1-215d-c2e04115e9fe" maxmem = 40000 memory = 40000 vcpus = 12 bootloader = "/usr/bin/pygrub" kernel = "/var/lib/xen/boot_kernel.nrTJko" ramdisk = "/var/lib/xen/boot_ramdisk.y6Gcn9" extra = "ro root=/dev/mapper/SYSTEM-root SYSFONT=latarcyrheb-sun16 LANG=en_AU.UTF-8 KEYTABLE=us console=hvc0 earlyprintk=xen" on_poweroff = "destroy" on_reboot = "restart" on_crash = "restart" vfb = [ "type=vnc,vncunused=1,keymap=en-us" ] disk = [ "phy:/dev/VM/system,xvda,w", "phy:/dev/VM/home,xvdb,w" ] vif = [ "mac=00:16:3e:7d:d0:91,bridge=xenbr0,script=vif-bridge,vifname=vif3.0" ] dom0# xm list Name ID Mem(MiB) VCPUs State Time(s) Domain-0 0 3907 16 r----- 66831.9 turing 1 40000 12 r----- 1842736.7 So it looks like I should have 40G of memory available to my guest. The guest boots like this (from /etc/grub.conf of guest): title Fedora (2.6.35.13-92.fc14.x86_64) root (hd0,0) kernel /vmlinuz-2.6.35.13-92.fc14.x86_64 ro root=/dev/mapper/SYSTEM-root SYSFONT=latarcyrheb-sun16 LANG=en_AU.UTF-8 KEYTABLE=us console=hvc0 earlyprintk=xen initrd /initramfs-2.6.35.13-92.fc14.x86_64.img However, the guest reports this: domU# grep MemTotal /proc/meminfo MemTotal: 32870604 kB What did I miss? Additional info: dom0# xm info host : neumann.une.edu.au release : 2.6.18-238.12.1.el5xen version : #1 SMP Tue May 31 14:02:29 EDT 2011 machine : x86_64 nr_cpus : 16 nr_nodes : 1 sockets_per_node : 4 cores_per_socket : 4 threads_per_core : 1 cpu_mhz : 2132 hw_caps : bfebfbff:20100800:00000000:00000940:000ce33d:00000000:00000001 total_memory : 65534 free_memory : 20354 node_to_cpu : node0:0-15 xen_major : 3 xen_minor : 1 xen_extra : .2-238.12.1.el5 xen_caps : xen-3.0-x86_64 xen-3.0-x86_32p hvm-3.0-x86_32 hvm-3.0-x86_32p hvm-3.0-x86_64 xen_pagesize : 4096 platform_params : virt_start=0xffff800000000000 xen_changeset : unavailable cc_compiler : gcc version 4.1.2 20080704 (Red Hat 4.1.2-50) cc_compile_by : mockbuild cc_compile_domain : centos.org cc_compile_date : Tue May 31 13:13:40 EDT 2011 xend_config_format : 2 -- Norman Gaywood, Computer Systems Officer University of New England, Armidale, NSW 2351, Australia ngaywood at une.edu.au Phone: +61 (0)2 6773 3337 http://mcs.une.edu.au/~norm Fax: +61 (0)2 6773 3312 Please avoid sending me Word or PowerPoint attachments. See http://www.gnu.org/philosophy/no-word-attachments.html
Norman Gaywood
2011-Jun-29 00:21 UTC
[CentOS-virt] More than 32G on memory in a domU guest?
Hmm bad form to answer myself, but: On Wed, Jun 29, 2011 at 09:41:18AM +1000, Norman Gaywood wrote:> dom0# cat /etc/xen/turing...> maxmem = 40000 > memory = 40000> dom0# xm list...> turing 1 40000 12 r----- 1842736.7> guest boots like this (from /etc/grub.conf of guest): > title Fedora (2.6.35.13-92.fc14.x86_64)> However, the guest reports this: > > domU# grep MemTotal /proc/meminfo > MemTotal: 32870604 kBI missed this in /usr/src/kernels/2.6.35.13-92.fc14.x86_64/.config CONFIG_PARAVIRT_GUEST=y CONFIG_XEN=y CONFIG_XEN_MAX_DOMAIN_MEMORY=32 So I guess that means that the fedora kernels are not built to use more than 32G of memory in DomU. -- Norman Gaywood, Computer Systems Officer University of New England, Armidale, NSW 2351, Australia ngaywood at une.edu.au Phone: +61 (0)2 6773 3337 http://mcs.une.edu.au/~norm Fax: +61 (0)2 6773 3312 Please avoid sending me Word or PowerPoint attachments. See http://www.gnu.org/philosophy/no-word-attachments.html