[ovirt-users] Re: About the vm memory limit
I can't recall - it was discussed here in the list and some users had troubles. I hope some of the devs can chime in. Best Regards, Strahil Nikolov В неделя, 26 септември 2021 г., 07:04:29 ч. Гринуич+3, Tommy Sway написа: In fact, I am very interested in the part you mentioned, because my environment is running relational database, which usually requires a large amount of memory, and some systems clearly need to configure HUGEPAGE memory (such as Oracle). Could you elaborate on some technical details about the management of huge page memory? And the difference between 4.3 and 4.4 in this respect? Thank you very much! From: Strahil Nikolov Sent: Saturday, September 25, 2021 5:32 PMTo: Tommy Sway Subject: Re: [ovirt-users] About the vm memory limit It depends on the numa configuration of the host. If you have 256G per CPU, it's best to stay into that range. Also, consider disabling transparent huge pages on the host & VM. Since 4.4 Regular Huge Pages (do not confuse them with THP) can be used on the Hypervisors, while on 4.3 there were some issues but I can't provode any details. Best Regards, Strahil Nikolov > On Fri, Sep 24, 2021 at 6:40, Tommy Sway > wrote: > I would like to ask if there is any limit on the memory size of virtual > machines, or performance curve or something like that? > As long as there is memory on the physical machine, the more virtual machines > the better? > > In our usage scenario, there are many virtual machines with databases, and > their memory varies greatly. > For some virtual machines, 4G memory is enough, while for some virtual > machines, 64GB memory is needed. > > I want to know what is the best use of memory for a virtual machine, since > the virtual machine is just a QEMU emulation process on a physical machine, > and I worry that it is not using as much memory as a physical machine. > Understand this so that we can develop guidelines for optimal memory usage > scenarios for virtual machines. > > Thank you! > > > ___Users mailing list -- > users@ovirt.orgTo unsubscribe send an email to users-leave@ovirt.orgPrivacy > Statement: https://www.ovirt.org/privacy-policy.htmloVirt Code of Conduct: > https://www.ovirt.org/community/about/community-guidelines/List Archives: > https://lists.ovirt.org/archives/list/users@ovirt.org/message/Y6XDOIMKCP4JEJF7M5DLJ33U2ENJKGAN/ ___ Users mailing list -- users@ovirt.org To unsubscribe send an email to users-le...@ovirt.org Privacy Statement: https://www.ovirt.org/privacy-policy.html oVirt Code of Conduct: https://www.ovirt.org/community/about/community-guidelines/ List Archives: https://lists.ovirt.org/archives/list/users@ovirt.org/message/CV453YBWVJ5EYCOUGVE5QUWN27GXQSF7/
[ovirt-users] Re: About the vm memory limit
Transparent huge pages are enabled by default, so you need to stop them. I would use huge pages on both host and VM, but theoretically it shouldn't be a problem running a VM with enabled HugePages without configuring on Host. Best Regards, Strahil Nikolov В събота, 25 септември 2021 г., 15:25:10 ч. Гринуич+3, Tommy Sway написа: transparent huge pages are not used on vm and physical host. But, can I enable hugepage memory on virtual machines but not on a physical machine? For database running on vm, and it needs to config hugepage. From: Strahil Nikolov Sent: Saturday, September 25, 2021 5:32 PMTo: Tommy Sway Subject: Re: [ovirt-users] About the vm memory limit It depends on the numa configuration of the host. If you have 256G per CPU, it's best to stay into that range. Also, consider disabling transparent huge pages on the host & VM. Since 4.4 Regular Huge Pages (do not confuse them with THP) can be used on the Hypervisors, while on 4.3 there were some issues but I can't provode any details. Best Regards, Strahil Nikolov > On Fri, Sep 24, 2021 at 6:40, Tommy Sway > wrote: > I would like to ask if there is any limit on the memory size of virtual > machines, or performance curve or something like that? > As long as there is memory on the physical machine, the more virtual machines > the better? > > In our usage scenario, there are many virtual machines with databases, and > their memory varies greatly. > For some virtual machines, 4G memory is enough, while for some virtual > machines, 64GB memory is needed. > > I want to know what is the best use of memory for a virtual machine, since > the virtual machine is just a QEMU emulation process on a physical machine, > and I worry that it is not using as much memory as a physical machine. > Understand this so that we can develop guidelines for optimal memory usage > scenarios for virtual machines. > > Thank you! > > > ___Users mailing list -- > users@ovirt.orgTo unsubscribe send an email to users-leave@ovirt.orgPrivacy > Statement: https://www.ovirt.org/privacy-policy.htmloVirt Code of Conduct: > https://www.ovirt.org/community/about/community-guidelines/List Archives: > https://lists.ovirt.org/archives/list/users@ovirt.org/message/Y6XDOIMKCP4JEJF7M5DLJ33U2ENJKGAN/ ___ Users mailing list -- users@ovirt.org To unsubscribe send an email to users-le...@ovirt.org Privacy Statement: https://www.ovirt.org/privacy-policy.html oVirt Code of Conduct: https://www.ovirt.org/community/about/community-guidelines/ List Archives: https://lists.ovirt.org/archives/list/users@ovirt.org/message/3YHTUBAG42YRNEUCWG4DF5TEP2I22DMH/ ___ Users mailing list -- users@ovirt.org To unsubscribe send an email to users-le...@ovirt.org Privacy Statement: https://www.ovirt.org/privacy-policy.html oVirt Code of Conduct: https://www.ovirt.org/community/about/community-guidelines/ List Archives: https://lists.ovirt.org/archives/list/users@ovirt.org/message/TBDRNXJ7B5SMHBWXFZI6OB55GWQO7N4M/
[ovirt-users] Re: About the vm memory limit
In fact, I am very interested in the part you mentioned, because my environment is running relational database, which usually requires a large amount of memory, and some systems clearly need to configure HUGEPAGE memory (such as Oracle). Could you elaborate on some technical details about the management of huge page memory? And the difference between 4.3 and 4.4 in this respect? Thank you very much! From: Strahil Nikolov Sent: Saturday, September 25, 2021 5:32 PM To: Tommy Sway Subject: Re: [ovirt-users] About the vm memory limit It depends on the numa configuration of the host. If you have 256G per CPU, it's best to stay into that range. Also, consider disabling transparent huge pages on the host & VM. Since 4.4 Regular Huge Pages (do not confuse them with THP) can be used on the Hypervisors, while on 4.3 there were some issues but I can't provode any details. Best Regards, Strahil Nikolov On Fri, Sep 24, 2021 at 6:40, Tommy Sway mailto:sz_cui...@163.com> > wrote: I would like to ask if there is any limit on the memory size of virtual machines, or performance curve or something like that? As long as there is memory on the physical machine, the more virtual machines the better? In our usage scenario, there are many virtual machines with databases, and their memory varies greatly. For some virtual machines, 4G memory is enough, while for some virtual machines, 64GB memory is needed. I want to know what is the best use of memory for a virtual machine, since the virtual machine is just a QEMU emulation process on a physical machine, and I worry that it is not using as much memory as a physical machine. Understand this so that we can develop guidelines for optimal memory usage scenarios for virtual machines. Thank you! ___ Users mailing list -- users@ovirt.org <mailto:users@ovirt.org> To unsubscribe send an email to users-le...@ovirt.org <mailto:users-le...@ovirt.org> Privacy Statement: https://www.ovirt.org/privacy-policy.html oVirt Code of Conduct: https://www.ovirt.org/community/about/community-guidelines/ List Archives: https://lists.ovirt.org/archives/list/users@ovirt.org/message/Y6XDOIMKCP4JEJF7M5DLJ33U2ENJKGAN/ ___ Users mailing list -- users@ovirt.org To unsubscribe send an email to users-le...@ovirt.org Privacy Statement: https://www.ovirt.org/privacy-policy.html oVirt Code of Conduct: https://www.ovirt.org/community/about/community-guidelines/ List Archives: https://lists.ovirt.org/archives/list/users@ovirt.org/message/VU3AOWKKYL3EDZHI46HMZOOGSVK2HMAE/
[ovirt-users] Re: About the vm memory limit
transparent huge pages are not used on vm and physical host. But, can I enable hugepage memory on virtual machines but not on a physical machine? For database running on vm, and it needs to config hugepage. From: Strahil Nikolov Sent: Saturday, September 25, 2021 5:32 PM To: Tommy Sway Subject: Re: [ovirt-users] About the vm memory limit It depends on the numa configuration of the host. If you have 256G per CPU, it's best to stay into that range. Also, consider disabling transparent huge pages on the host & VM. Since 4.4 Regular Huge Pages (do not confuse them with THP) can be used on the Hypervisors, while on 4.3 there were some issues but I can't provode any details. Best Regards, Strahil Nikolov On Fri, Sep 24, 2021 at 6:40, Tommy Sway mailto:sz_cui...@163.com> > wrote: I would like to ask if there is any limit on the memory size of virtual machines, or performance curve or something like that? As long as there is memory on the physical machine, the more virtual machines the better? In our usage scenario, there are many virtual machines with databases, and their memory varies greatly. For some virtual machines, 4G memory is enough, while for some virtual machines, 64GB memory is needed. I want to know what is the best use of memory for a virtual machine, since the virtual machine is just a QEMU emulation process on a physical machine, and I worry that it is not using as much memory as a physical machine. Understand this so that we can develop guidelines for optimal memory usage scenarios for virtual machines. Thank you! ___ Users mailing list -- users@ovirt.org <mailto:users@ovirt.org> To unsubscribe send an email to users-le...@ovirt.org <mailto:users-le...@ovirt.org> Privacy Statement: https://www.ovirt.org/privacy-policy.html oVirt Code of Conduct: https://www.ovirt.org/community/about/community-guidelines/ List Archives: https://lists.ovirt.org/archives/list/users@ovirt.org/message/Y6XDOIMKCP4JEJF7M5DLJ33U2ENJKGAN/ ___ Users mailing list -- users@ovirt.org To unsubscribe send an email to users-le...@ovirt.org Privacy Statement: https://www.ovirt.org/privacy-policy.html oVirt Code of Conduct: https://www.ovirt.org/community/about/community-guidelines/ List Archives: https://lists.ovirt.org/archives/list/users@ovirt.org/message/3YHTUBAG42YRNEUCWG4DF5TEP2I22DMH/
