Hi Thanks for the responses. Of course the LX machines will need the zones/swap which I did not realize.
cheers Len On Sun, 2 Oct 2016 at 23:42 Nigel W <[email protected]> wrote: > On Sep 29, 2016 2:03 PM, "Len Weincier" <[email protected]> wrote: > > > > Hi > Hi > > > > > We have some new hosts with 1.5T memory and this causes a zones/swap of > 1.5T to be created. > > Is this necessary in the GZ ? Each VM gets its own swap so just not sure > what would be running in the GZ that would end u using that swap ? > > > > Yes, it could be a good idea depending on your use case. > > If you are using LX or joyent zones, they are assigned out of the GZ's > resources and the since the illumos kernel does not over commit memory, all > memory allocated by a process must be backed in the GZ in either RAM or > swap, so having 0.5x to 1x "max_physical_mem" in "swap". > > KVM zones are a bit different because they will have their own swap as > part of the allocated zvol using whatever mechanism the guest OS uses. > However, even heavy KVM zone hosts benefit from a lot of swap because they > need to allocate all of the guests memory up front so having a large swap > helps deal the memory fragmentation as the host gets to capacity. > > Of couse because the swap is just a zvol, you can reduce the swap dataset > if you like using using the normal zvol commands: > > zfs set volsize=<size> zones/swap > > I don't recall if shrinking zones/swap needs to be done while the host is > in noimport mode though. > *smartos-discuss* | Archives > <https://www.listbox.com/member/archive/184463/=now> > <https://www.listbox.com/member/archive/rss/184463/22274172-7bba44bb> | > Modify > <https://www.listbox.com/member/?&;> > Your Subscription <http://www.listbox.com> > ------------------------------------------- smartos-discuss Archives: https://www.listbox.com/member/archive/184463/=now RSS Feed: https://www.listbox.com/member/archive/rss/184463/25769125-55cfbc00 Modify Your Subscription: https://www.listbox.com/member/?member_id=25769125&id_secret=25769125-7688e9fb Powered by Listbox: http://www.listbox.com
