> On Fri, Mar 04, 2016 at 06:51:21PM +0000, Dr. David Alan Gilbert wrote: > > * Paolo Bonzini (pbonzini@xxxxxxxxxx) wrote: > > > > > > > > > On 04/03/2016 15:26, Li, Liang Z wrote: > > > >> > > > > >> > The memory usage will keep increasing due to ever growing > > > >> > caches, etc, so you'll be left with very little free memory fairly soon. > > > >> > > > > > I don't think so. > > > > > > > > > > Roman is right. For example, here I am looking at a 64 GB > > > (physical) machine which was booted about 30 minutes ago, and which > > > is running disk-heavy workloads (installing VMs). > > > > > > Since I have started writing this email (2 minutes?), the amount of > > > free memory has already gone down from 37 GB to 33 GB. I expect > > > that by the time I have finished running the workload, in two hours, > > > it will not have any free memory. > > > > But what about a VM sitting idle, or that just has more RAM assigned > > to it than is currently using. > > I've got a host here that's been up for 46 days and has been doing > > some heavy VM debugging a few days ago, but today: > > > > # free -m > > total used free shared buff/cache available > > Mem: 96536 1146 44834 184 50555 94735 > > > > I very rarely use all it's RAM, so it's got a big chunk of free RAM, > > and yes it's got a big chunk of cache as well. > > One of the promises of virtualization is better resource utilization. > People tend to avoid purchasing VMs so much oversized that they never > touch a significant amount of their RAM. (Well, at least this is how things > stand in hosting market; I guess enterprize market is similar in this regard). > > That said, I'm not at all opposed to optimizing the migration of free memory; > what I'm trying to say is that creating brand new infrastructure specifically for > that case doesn't look justified when the existing one can cover it in addition > to much more common scenarios. > > Roman. Even the existing one can cover more common scenarios, but it has performance issue. that's why I create a new one. Liang _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
