https://wiki.openvz.org/index.php?action=history&feed=atom&title=Memory_guarantees_for_Containers_and_Virtual_Machines 2026-08-14T03:40:06Z Revision history for this page on the wiki MediaWiki 1.31.1 https://wiki.openvz.org/index.php?title=Memory_guarantees_for_Containers_and_Virtual_Machines&diff=19172&oldid=prev 2016-01-28T10:13:57Z

<p>Created page with &quot;== Feature == Memory guarantees for Containers and Virtual Machines https://jira.sw.ru/browse/PSBM-42670 == Description == It&#039;s possible to define memory guarantees for bot...&quot;</p> <p><b>New page</b></p><div>== Feature ==<br /> <br /> Memory guarantees for Containers and Virtual Machines https://jira.sw.ru/browse/PSBM-42670<br /> <br /> == Description ==<br /> <br /> It's possible to define memory guarantees for both Containers and Virtual Machines. VCMMD must ensure dynamic memory configuration of Virtual Environments never screw up defined VEs memory guarantees.<br /> <br /> How to set up memory guarantee for a VE:<br /> <br /> # prlctl set VE --memguarantee [%]<br /> <br /> Examples:<br /> <br /> prlctl set VE --memguarantee 50<br /> prlctl set VE --memguarantee auto<br /> <br /> Note: &quot;auto&quot; is for default value (40% for VMs, 20% for CTs)<br /> <br /> Unlimited Containers have [FIXME] % memory guarantees by default. (Virtual Machines cannot be &quot;unlimited&quot; by design.)<br /> <br /> == Products ==<br /> <br /> Virtuozzo 7<br /> <br /> Packages:<br /> <br /> * vcmmd-7.0.38-1<br /> * vzkernel-3.10.0-229.7.2.vz7.9.29<br /> * prl-disp-service-7.0.235<br /> * prlctl-7.0.33<br /> * vzctl-7.0.85<br /> <br /> == Testing ==<br /> <br /> * host RAM=X, total sum of currently running VEs = Y (Y&lt;X)<br /> You are trying to start a VE with memory guarantee Z (or increase the memory guarantee for existing VE to Z).<br /> <br /> a) if Z &gt; X - Y - min(X*0.05, 1Gb), operation should fail<br /> b) if Z &lt; (X - Y - min(X*0.05, 1Gb)) * 0.95, operation should succeed<br /> <br /> * for each running VE, it should be able to allocate and use memory without OOM,<br /> if total VE usage is not greater than VE's memory limit<br /> <br /> * Attempt to set --memquota must fail (otherwise - broken expectations) and print reasonable error message,<br /> like &quot;This option is deprecated, please use —memguarantee instead&quot;.<br /> https://jira.sw.ru/browse/PSBM-41963<br /> <br /> == Known issues ==<br /> <br /> * 'prlctl start VM' is the only way to start VM with memory guarantee<br /> (In other words in case you start a VM via virsh, memory guarantees won't work for sure.)<br /> https://jira.sw.ru/browse/PSBM-43106<br /> <br /> == What was checked by developer ==<br /> <br /> * cgroups' lowlimit never goes lower than memory guarantees set for a Container<br /> <br /> == Feature owner ==<br /> <br /> * vcmmd part - vdavydov at virtuozzo.com<br /> * prlctl part - dandreev at virtuozzo.com<br /> * dispatcher parts - shrike at virtuozzo.com, igor at virtuozzo.com, dandreev at virtuozzo.com<br /> * vzctl part - igor at virtuozzo.com</div>

Sergey Bronnikov