What problem will appear if I use the default transparent huge page enabled mode for physical hosts, but configure traditional huge page memory on the virtual machine for database SGA ?
Or is it better to disable transparent huge page on physical machines and still use traditional huge page memory on virtual machines? Which one is prefer ? From: users-boun...@ovirt.org <users-boun...@ovirt.org> On Behalf Of Strahil Nikolov via Users Sent: Tuesday, September 28, 2021 12:05 AM To: tommy <sz_cui...@163.com>; 'users' <users@ovirt.org> Subject: [ovirt-users]Re: 回复： Re: About the vm memory limit https://docs.oracle.com/en/database/oracle/oracle-database/19/ladbi/disabling-transparent-hugepages.html https://access.redhat.com/solutions/1320153 (requires RH dev subscription or other type of subscription) -> In short add 'transparent_hugepage=never' to the kernel params SLES11/12/15 -> https://www.suse.com/c/sles-1112-os-tuning-optimisation-guide-part-1/ Best Regards, Strahil Nikolov On Mon, Sep 27, 2021 at 16:33, tommy <sz_cui...@163.com <mailto:sz_cui...@163.com> > wrote: thank you! and how to get the config info of Transparent huge pages and how to disable it？ 发自我的华为手机 -------- 原始邮件 -------- 发件人： Strahil Nikolov <hunter86...@yahoo.com <mailto:hunter86...@yahoo.com> > 日期： 2021年9月27日周一 21:13 收件人： 'users' <users@ovirt.org <mailto:users@ovirt.org> >, Tommy Sway <sz_cui...@163.com <mailto:sz_cui...@163.com> > 主 题： Re: [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 <sz_cui...@163.com <mailto:sz_cui...@163.com> > 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 <hunter86...@yahoo.com <mailto:hunter86...@yahoo.com> > Sent: Saturday, September 25, 2021 5:32 PMTo: Tommy Sway <sz_cui...@163.com <mailto:sz_cui...@163.com> >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 > <sz_cui...@163.com <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.orgTo <mailto:users@ovirt.orgTo> unsubscribe send an email to > users-leave@ovirt.orgPrivacy <mailto: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 <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/3YHTUBAG42YRNEUCWG4DF5TEP2I22DMH/
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