[ovirt-users] Free Memory In Hosts
Hi All, I have noticed that there is a huge difference between memory reading obtained from top or free commands, and values displayed on ovirt engine. "Host " Example: Engine Version : *ovirt-engine-3.4.3-1.el6.noarch* *OS: Centos 6.5_x86_64* *Used Memory:* *from free:* [root@oVirt ~]# free total used free sharedbuffers cached Mem: 65890412 65609864 280548 0 305408 53759412 from Egnine Webpage: only 12G is being used. Is there an explanation for this ? Please note this is the same on all previous version, the values matches only after restart of the host then free memory start to vanish by time ! Thanks, Mohyedeen. ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
Re: [ovirt-users] Free Memory In Hosts
Hi, If you look at the full free output you will see another line: total used free sharedbuffers cached Mem: 80570047491980 565024 0 2345922005452 -/+ buffers/cache:52519362805068 The +/- buffers/cache tells you how much memory you will have available after you (the kernel) clean all buffers and caches. And that is the number we look at. -- Martin Sivák msi...@redhat.com Red Hat Czech RHEV-M SLA / Brno, CZ - Original Message - > On Wed, Sep 10, 2014 at 11:57:05PM +0300, Mohyedeen Nazzal wrote: > > Hi All, > > I have noticed that there is a huge difference between memory reading > > obtained from top or free commands, and values displayed on ovirt engine. > > "Host " > > > > Example: > > Engine Version : *ovirt-engine-3.4.3-1.el6.noarch* > > *OS: Centos 6.5_x86_64* > > > > *Used Memory:* > > *from free:* > > [root@oVirt ~]# free > > total used free sharedbuffers > > cached > > Mem: 65890412 65609864 280548 0 305408 53759412 > > > > from Egnine Webpage: > > > > only 12G is being used. > > > > Is there an explanation for this ? > > It's a Linux thing. When a file is opened, it is mapped into memory, but > when it is closed Linux does not evict it before memory is released > again. Thus, a long-running active host reaches 0 free mem sooner than > later. > > For oVirt GUI, we found this misleading - there, "free" means "how much > memory is available for new VMs to use". Therefore oVirt reports > "buffred" and "cached" memory as free, too. > ___ > 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
Re: [ovirt-users] Free Memory In Hosts
On Wed, Sep 10, 2014 at 11:57:05PM +0300, Mohyedeen Nazzal wrote: > Hi All, > I have noticed that there is a huge difference between memory reading > obtained from top or free commands, and values displayed on ovirt engine. > "Host " > > Example: > Engine Version : *ovirt-engine-3.4.3-1.el6.noarch* > *OS: Centos 6.5_x86_64* > > *Used Memory:* > *from free:* > [root@oVirt ~]# free > total used free sharedbuffers > cached > Mem: 65890412 65609864 280548 0 305408 53759412 > > from Egnine Webpage: > > only 12G is being used. > > Is there an explanation for this ? It's a Linux thing. When a file is opened, it is mapped into memory, but when it is closed Linux does not evict it before memory is released again. Thus, a long-running active host reaches 0 free mem sooner than later. For oVirt GUI, we found this misleading - there, "free" means "how much memory is available for new VMs to use". Therefore oVirt reports "buffred" and "cached" memory as free, too. ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
[ovirt-users] Free Memory In Hosts
Hi All, I have noticed that there is a huge difference between memory reading obtained from top or free commands, and values displayed on ovirt engine. "Host " Example: Engine Version : *ovirt-engine-3.4.3-1.el6.noarch* *OS: Centos 6.5_x86_64* *Used Memory:* *from free:* [root@oVirt ~]# free total used free sharedbuffers cached Mem: 65890412 65609864 280548 0 305408 53759412 from Egnine Webpage: only 12G is being used. Is there an explanation for this ? Please note this is the same on all previous version, the values matches only after restart of the host then free memory start to vanish by time ! Thanks, Mohyedeen. ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
