This is a multi-part message in MIME format. --------------080308040608050209070102 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit Hello, Is hot add ram to a vm is supported by ovirt, or is it planned to be? -- Nathanaël Blanchet Supervision réseau Pôle exploitation et maintenance Département des systèmes d'information 227 avenue Professeur-Jean-Louis-Viala 34193 MONTPELLIER CEDEX 5 Tél. 33 (0)4 67 54 84 55 Fax 33 (0)4 67 54 84 14 blanchet@abes.fr --------------080308040608050209070102 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit <html> <head> <meta http-equiv="content-type" content="text/html; charset=ISO-8859-1"> </head> <body bgcolor="#FFFFFF" text="#000000"> <font size="-1">Hello,<br> <br> Is hot add ram to a vm is supported by ovirt, or is it planned to be?<br> </font> <pre class="moz-signature" cols="72">-- Nathanaël Blanchet Supervision réseau Pôle exploitation et maintenance Département des systèmes d'information 227 avenue Professeur-Jean-Louis-Viala 34193 MONTPELLIER CEDEX 5 Tél. 33 (0)4 67 54 84 55 Fax 33 (0)4 67 54 84 14 <a class="moz-txt-link-abbreviated" href="mailto:blanchet@abes.fr">blanchet@abes.fr</a> </pre> </body> </html> --------------080308040608050209070102--
On Mon, Dec 09, 2013 at 05:27:16PM +0100, Nathanaël Blanchet wrote:
Hello,
Is hot add ram to a vm is supported by ovirt, or is it planned to be?
Not at the moment, I'm afraid. For some use cases, the recomended approach is to start a VM with way-too-much ram, but inflate a big balloon in it. When more memory is required on the VM, set a higher guaranteed level of RAM. Dan.
On 12/09/2013 06:51 PM, Dan Kenigsberg wrote:
On Mon, Dec 09, 2013 at 05:27:16PM +0100, Nathanaël Blanchet wrote:
Hello,
Is hot add ram to a vm is supported by ovirt, or is it planned to be?
Not at the moment, I'm afraid. For some use cases, the recomended approach is to start a VM with way-too-much ram, but inflate a big balloon in it. When more memory is required on the VM, set a higher guaranteed level of RAM.
Dan. _______________________________________________ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
we're working on hot add cpu now. then we'll start looking into hot add ram. may i ask which guest OS are you looking at and the use case you are trying to solve? thanks, Itamar
On 12/09/2013 06:51 PM, Dan Kenigsberg wrote:
On Mon, Dec 09, 2013 at 05:27:16PM +0100, Nathanaël Blanchet wrote:
Hello,
Is hot add ram to a vm is supported by ovirt, or is it planned to be?
Not at the moment, I'm afraid. For some use cases, the recomended approach is to start a VM with way-too-much ram, but inflate a big balloon in it. When more memory is required on the VM, set a higher guaranteed level of RAM.
Dan. _______________________________________________ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
we're working on hot add cpu now. then we'll start looking into hot add ram. may i ask which guest OS are you looking at and the use case you are trying to solve?
thanks, Itamar We run many centos guests with ton of tomcats on it, and they are in
Le 09/12/2013 19:32, Itamar Heim a écrit : production. Downtime is forbidden but we need more and more RAM because we often add new applications. -- Nathanaël Blanchet Supervision réseau Pôle exploitation et maintenance Département des systèmes d'information 227 avenue Professeur-Jean-Louis-Viala 34193 MONTPELLIER CEDEX 5 Tél. 33 (0)4 67 54 84 55 Fax 33 (0)4 67 54 84 14 blanchet@abes.fr
Hi, just want to say that we are also interested in this feature. -- Mit freundlichen Grüßen / Regards Sven Kieske Systemadministrator Mittwald CM Service GmbH & Co. KG Königsberger Straße 6 32339 Espelkamp T: +49-5772-293-100 F: +49-5772-293-333 https://www.mittwald.de Geschäftsführer: Robert Meyer St.Nr.: 331/5721/1033, USt-IdNr.: DE814773217, HRA 6640, AG Bad Oeynhausen Komplementärin: Robert Meyer Verwaltungs GmbH, HRB 13260, AG Bad Oeynhausen
Too bad QEMU doesn't support it. So it's still a long way. Balloon should be able to cover most of the use cases. You have overcommit and can reserve only a part of RAM, then change the reserved amount which adds more RAM resources. OS still sees the same (maximum) size, but effectively it allows similar usage as hot add ram Thanks, michal On Dec 12, 2013, at 23:38 , Sigbjorn Lie <sigbjorn@nixtra.com> wrote:
+1 for this feature
On 10/12/13 10:00, Sven Kieske wrote:
Hi,
just want to say that we are also interested in this feature.
_______________________________________________ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
On Fri, Dec 13, 2013 at 1:42 PM, Michal Skrivanek <michal.skrivanek@redhat.com> wrote:
Too bad QEMU doesn't support it. So it's still a long way.
qemu/libvirt "kind of" supports it (at least in F19). In virt-manager you can define "current" and "maximum" memory allocation. The VM only sees the current allocation and you can hot add memory up to the maximum allocation. Example from the xml definition: <memory unit='KiB'>3145728</memory> <currentMemory unit='KiB'>1048576</currentMemory> After booting: [root@grkvm201 ~]# uname -a Linux grkvm201.plusine.intern 2.6.32-358.23.2.el6.x86_64 #1 SMP Wed Oct 16 18:37:12 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux [root@grkvm201 ~]# free -lm total used free shared buffers cached Mem: 837 296 540 0 8 84 Low: 837 296 540 High: 0 0 0 -/+ buffers/cache: 203 634 Swap: 511 0 511 [root@grkvm201 ~]# memory increased to 2GB through virt-manager: [root@grkvm201 ~]# free -lm total used free shared buffers cached Mem: 1861 295 1565 0 8 84 Low: 1861 295 1565 High: 0 0 0 -/+ buffers/cache: 202 1659 Swap: 511 0 511 [root@grkvm201 ~]# cat /proc/meminfo MemTotal: 1906176 kB MemFree: 1603456 kB Buffers: 9140 kB Cached: 86860 kB SwapCached: 0 kB Active: 92564 kB Inactive: 68064 kB Active(anon): 68692 kB Inactive(anon): 12 kB Active(file): 23872 kB Inactive(file): 68052 kB Unevictable: 21600 kB Mlocked: 11380 kB SwapTotal: 524280 kB SwapFree: 524280 kB Dirty: 12 kB Writeback: 0 kB AnonPages: 86232 kB Mapped: 20436 kB Shmem: 288 kB Slab: 75132 kB SReclaimable: 14576 kB SUnreclaim: 60556 kB KernelStack: 1464 kB PageTables: 4224 kB NFS_Unstable: 0 kB Bounce: 0 kB WritebackTmp: 0 kB CommitLimit: 1477368 kB Committed_AS: 547624 kB VmallocTotal: 34359738367 kB VmallocUsed: 20040 kB VmallocChunk: 34359688500 kB HardwareCorrupted: 0 kB AnonHugePages: 18432 kB HugePages_Total: 0 HugePages_Free: 0 HugePages_Rsvd: 0 Memory decreased to 1,5GB through virt-manager: [root@grkvm201 ~]# free -lm total used free shared buffers cached Mem: 1349 295 1054 0 8 84 Low: 1349 295 1054 High: 0 0 0 -/+ buffers/cache: 201 1147 Swap: 511 0 511 [root@grkvm201 ~]#
----- Original Message -----
From: "Sander Grendelman" <sander@grendelman.com> To: "Michal Skrivanek" <michal.skrivanek@redhat.com> Cc: users@ovirt.org Sent: Friday, December 13, 2013 8:52:42 AM Subject: Re: [Users] hot add ram to a vm
On Fri, Dec 13, 2013 at 1:42 PM, Michal Skrivanek <michal.skrivanek@redhat.com> wrote:
Too bad QEMU doesn't support it. So it's still a long way.
qemu/libvirt "kind of" supports it (at least in F19).
In virt-manager you can define "current" and "maximum" memory allocation.
The VM only sees the current allocation and you can hot add memory up to the maximum allocation.
It isn't really hot-plug. This allows you to statically set the physical ram but then use the balloon device to "borrow" some ram from the guest. If max memory was 4gb and we set current memory to 2gb the VM would still see 4gb of physical memory but the balloon driver would be taking up 2gb of memory in the guest, this memory would be returned to the host for other VMs to use.
Example from the xml definition:
<memory unit='KiB'>3145728</memory> <currentMemory unit='KiB'>1048576</currentMemory>
After booting:
[root@grkvm201 ~]# uname -a Linux grkvm201.plusine.intern 2.6.32-358.23.2.el6.x86_64 #1 SMP Wed Oct 16 18:37:12 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux [root@grkvm201 ~]# free -lm total used free shared buffers cached Mem: 837 296 540 0 8 84 Low: 837 296 540 High: 0 0 0 -/+ buffers/cache: 203 634 Swap: 511 0 511 [root@grkvm201 ~]#
memory increased to 2GB through virt-manager:
[root@grkvm201 ~]# free -lm total used free shared buffers cached Mem: 1861 295 1565 0 8 84 Low: 1861 295 1565 High: 0 0 0 -/+ buffers/cache: 202 1659 Swap: 511 0 511 [root@grkvm201 ~]# cat /proc/meminfo MemTotal: 1906176 kB MemFree: 1603456 kB Buffers: 9140 kB Cached: 86860 kB SwapCached: 0 kB Active: 92564 kB Inactive: 68064 kB Active(anon): 68692 kB Inactive(anon): 12 kB Active(file): 23872 kB Inactive(file): 68052 kB Unevictable: 21600 kB Mlocked: 11380 kB SwapTotal: 524280 kB SwapFree: 524280 kB Dirty: 12 kB Writeback: 0 kB AnonPages: 86232 kB Mapped: 20436 kB Shmem: 288 kB Slab: 75132 kB SReclaimable: 14576 kB SUnreclaim: 60556 kB KernelStack: 1464 kB PageTables: 4224 kB NFS_Unstable: 0 kB Bounce: 0 kB WritebackTmp: 0 kB CommitLimit: 1477368 kB Committed_AS: 547624 kB VmallocTotal: 34359738367 kB VmallocUsed: 20040 kB VmallocChunk: 34359688500 kB HardwareCorrupted: 0 kB AnonHugePages: 18432 kB HugePages_Total: 0 HugePages_Free: 0 HugePages_Rsvd: 0
Memory decreased to 1,5GB through virt-manager: [root@grkvm201 ~]# free -lm total used free shared buffers cached Mem: 1349 295 1054 0 8 84 Low: 1349 295 1054 High: 0 0 0 -/+ buffers/cache: 201 1147 Swap: 511 0 511 [root@grkvm201 ~]# _______________________________________________ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
----- Original Message -----
From: "Andrew Cathrow" <acathrow@redhat.com> To: "Sander Grendelman" <sander@grendelman.com> Cc: users@ovirt.org Sent: Monday, December 16, 2013 2:05:00 PM Subject: Re: [Users] hot add ram to a vm
----- Original Message -----
From: "Sander Grendelman" <sander@grendelman.com> To: "Michal Skrivanek" <michal.skrivanek@redhat.com> Cc: users@ovirt.org Sent: Friday, December 13, 2013 8:52:42 AM Subject: Re: [Users] hot add ram to a vm
On Fri, Dec 13, 2013 at 1:42 PM, Michal Skrivanek <michal.skrivanek@redhat.com> wrote:
Too bad QEMU doesn't support it. So it's still a long way.
qemu/libvirt "kind of" supports it (at least in F19).
In virt-manager you can define "current" and "maximum" memory allocation.
The VM only sees the current allocation and you can hot add memory up to the maximum allocation.
It isn't really hot-plug. This allows you to statically set the physical ram but then use the balloon device to "borrow" some ram from the guest. If max memory was 4gb and we set current memory to 2gb the VM would still see 4gb of physical memory but the balloon driver would be taking up 2gb of memory in the guest, this memory would be returned to the host for other VMs to use.
Right, currentMemory is how you manipulate the balloon: http://libvirt.org/formatdomain.html#elementsMemoryAllocation Note that is requires an agent, a driver and cooperation from the guest.
Example from the xml definition:
<memory unit='KiB'>3145728</memory> <currentMemory unit='KiB'>1048576</currentMemory>
After booting:
[root@grkvm201 ~]# uname -a Linux grkvm201.plusine.intern 2.6.32-358.23.2.el6.x86_64 #1 SMP Wed Oct 16 18:37:12 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux [root@grkvm201 ~]# free -lm total used free shared buffers cached Mem: 837 296 540 0 8 84 Low: 837 296 540 High: 0 0 0 -/+ buffers/cache: 203 634 Swap: 511 0 511 [root@grkvm201 ~]#
memory increased to 2GB through virt-manager:
[root@grkvm201 ~]# free -lm total used free shared buffers cached Mem: 1861 295 1565 0 8 84 Low: 1861 295 1565 High: 0 0 0 -/+ buffers/cache: 202 1659 Swap: 511 0 511 [root@grkvm201 ~]# cat /proc/meminfo MemTotal: 1906176 kB MemFree: 1603456 kB Buffers: 9140 kB Cached: 86860 kB SwapCached: 0 kB Active: 92564 kB Inactive: 68064 kB Active(anon): 68692 kB Inactive(anon): 12 kB Active(file): 23872 kB Inactive(file): 68052 kB Unevictable: 21600 kB Mlocked: 11380 kB SwapTotal: 524280 kB SwapFree: 524280 kB Dirty: 12 kB Writeback: 0 kB AnonPages: 86232 kB Mapped: 20436 kB Shmem: 288 kB Slab: 75132 kB SReclaimable: 14576 kB SUnreclaim: 60556 kB KernelStack: 1464 kB PageTables: 4224 kB NFS_Unstable: 0 kB Bounce: 0 kB WritebackTmp: 0 kB CommitLimit: 1477368 kB Committed_AS: 547624 kB VmallocTotal: 34359738367 kB VmallocUsed: 20040 kB VmallocChunk: 34359688500 kB HardwareCorrupted: 0 kB AnonHugePages: 18432 kB HugePages_Total: 0 HugePages_Free: 0 HugePages_Rsvd: 0
Memory decreased to 1,5GB through virt-manager: [root@grkvm201 ~]# free -lm total used free shared buffers cached Mem: 1349 295 1054 0 8 84 Low: 1349 295 1054 High: 0 0 0 -/+ buffers/cache: 201 1147 Swap: 511 0 511 [root@grkvm201 ~]# _______________________________________________ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
_______________________________________________ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
participants (9)
-
Andrew Cathrow -
Dan Kenigsberg -
Doron Fediuck -
Itamar Heim -
Michal Skrivanek -
Nathanaël Blanchet -
Sander Grendelman -
Sigbjorn Lie -
Sven Kieske