You don't need a >1TB host to spin up a >1TB guest. Unless you're using pci passthru (and/or SRIOV), or something else that requires qemu to alloc and pin all guest mem, you can simply overcommit; normal guests don't require mem pre-allocation or pinning.
On your host do this to allow overcommitting such a large amount (this allows 16T but can be adjusted as needed): $ echo $[ 16 * 1024 * 1024 * 1024 ] | sudo tee /proc/sys/vm/overcommit_kbytes 17179869184 $ echo 1 | sudo tee /proc/sys/vm/overcommit_memory 1 Then just virsh edit your guest to use >1TB, e.g.: <memory unit='GiB'>1500</memory> And of course, stop and restart the guest to pick up the xml change. -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1769053 Title: Cannot start a guest with more than 1TB of RAM Status in QEMU: Incomplete Status in qemu package in Ubuntu: Incomplete Bug description: Attempting to start a KVM guest with more than 1TB of RAM fails. It looks like we might need some extra patches: https://lists.gnu.org/archive/html/qemu-discuss/2017-12/msg00005.html ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: qemu-system-x86 1:2.11+dfsg-1ubuntu7 ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17 Uname: Linux 4.15.0-20-generic x86_64 ApportVersion: 2.20.9-0ubuntu7 Architecture: amd64 CurrentDesktop: Unity:Unity7:ubuntu Date: Fri May 4 16:21:14 2018 InstallationDate: Installed on 2017-04-05 (393 days ago) InstallationMedia: Ubuntu 16.10 "Yakkety Yak" - Release amd64 (20161012.2) MachineType: Dell Inc. XPS 13 9360 ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.15.0-20-generic root=/dev/mapper/ubuntu--vg-root ro quiet splash transparent_hugepage=madvise vt.handoff=1 SourcePackage: qemu UpgradeStatus: Upgraded to bionic on 2018-04-30 (3 days ago) dmi.bios.date: 02/26/2018 dmi.bios.vendor: Dell Inc. dmi.bios.version: 2.6.2 dmi.board.name: 0PF86Y dmi.board.vendor: Dell Inc. dmi.board.version: A00 dmi.chassis.type: 9 dmi.chassis.vendor: Dell Inc. dmi.modalias: dmi:bvnDellInc.:bvr2.6.2:bd02/26/2018:svnDellInc.:pnXPS139360:pvr:rvnDellInc.:rn0PF86Y:rvrA00:cvnDellInc.:ct9:cvr: dmi.product.family: XPS dmi.product.name: XPS 13 9360 dmi.sys.vendor: Dell Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1769053/+subscriptions
