I would like to use more than 832MB for a single domU. dmesg for the domU says: BIOS-provided physical RAM map: Xen: 0000000000000000 - 000000001b600000 (usable) Warning only 832MB will be used. Use a HIGHMEM enabled kernel. 832MB LOWMEM available. The kernel configuration has: CONFIG_NOHIGHMEM=y # CONFIG_HIGHMEM4G is not set What options should I set here? I would like to give up to about 1.5GB to a domU. Why is highmem disabled by default? Any negative effects on the stability, are there known problems? Best Regards, Michael Paesold _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Sat, 2005-09-10 at 14:09 +0200, Michael Paesold wrote:> I would like to use more than 832MB for a single domU. dmesg for the > domU says: > > BIOS-provided physical RAM map: > Xen: 0000000000000000 - 000000001b600000 (usable) > Warning only 832MB will be used. > Use a HIGHMEM enabled kernel. > 832MB LOWMEM available. > > The kernel configuration has: > > CONFIG_NOHIGHMEM=y > # CONFIG_HIGHMEM4G is not set > > What options should I set here? I would like to give up to about 1.5GB > to a domU. Why is highmem disabled by default? Any negative effects on > the stability, are there known problems?Try it and let us know :-) On my box with unstable on it. CONFIG_HIGHMEM4G=y [root@inyoureyes ~]# xm info system : Linux host : inyoureyes.linsolutions.com release : 2.6.12-xen0 version : #2 SMP Fri Sep 9 09:45:03 EDT 2005 machine : i686 cores_per_socket : 1 threads_per_core : 1 cpu_mhz : 1592 memory : 2047 free_memory : 1687 xen_major : 3 xen_minor : 0 xen_extra : -devel xen_changeset : cc_compiler : gcc version 4.0.1 20050727 (Red Hat 4.0.1-5) cc_compile_by : root cc_compile_domain : linsolutions.com cc_compile_date : Fri Sep 9 09:02:38 EDT 2005> > Best Regards, > Michael PaesoldRegards, Ted _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Ted Kaczmarek wrote:> On Sat, 2005-09-10 at 14:09 +0200, Michael Paesold wrote: > >>I would like to use more than 832MB for a single domU. dmesg for the >>domU says: >> >>BIOS-provided physical RAM map: >> Xen: 0000000000000000 - 000000001b600000 (usable) >>Warning only 832MB will be used. >>Use a HIGHMEM enabled kernel. >>832MB LOWMEM available. >> >>The kernel configuration has: >> >>CONFIG_NOHIGHMEM=y >># CONFIG_HIGHMEM4G is not set >> >>What options should I set here? I would like to give up to about 1.5GB >>to a domU. Why is highmem disabled by default? Any negative effects on >>the stability, are there known problems? > > Try it and let us know :-)Well, I though there must be someone to _know_. At least the person who decided to default to CONFIG_NOHIGHMEM on 2.0. 3.0 could be a whole different. Do you have the default kernel installed or is this the FC 4 package?> On my box with unstable on it. > > CONFIG_HIGHMEM4G=y> [root@inyoureyes ~]# xm info > system : Linux > host : inyoureyes.linsolutions.com > release : 2.6.12-xen0 > version : #2 SMP Fri Sep 9 09:45:03 EDT 2005 > machine : i686 > cores_per_socket : 1 > threads_per_core : 1 > cpu_mhz : 1592 > memory : 2047 > free_memory : 1687... This does not tell me much: Xen itself can always see the full memory, at least up to the amount the bios doesn''t use for PCI etc. (In machines > ~3 GB RAM, without PAE). Could you create a domain with more than 1 GB memory and then post the dmesg output corresponding to the one I gave above? Thanks. Best Regards, Michael Paesold _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Sat, 2005-09-10 at 19:28 +0200, Michael Paesold wrote:> Ted Kaczmarek wrote: > > On Sat, 2005-09-10 at 14:09 +0200, Michael Paesold wrote: > > > >>I would like to use more than 832MB for a single domU. dmesg for the > >>domU says: > >> > >>BIOS-provided physical RAM map: > >> Xen: 0000000000000000 - 000000001b600000 (usable) > >>Warning only 832MB will be used. > >>Use a HIGHMEM enabled kernel. > >>832MB LOWMEM available. > >> > >>The kernel configuration has: > >> > >>CONFIG_NOHIGHMEM=y > >># CONFIG_HIGHMEM4G is not set > >> > >>What options should I set here? I would like to give up to about 1.5GB > >>to a domU. Why is highmem disabled by default? Any negative effects on > >>the stability, are there known problems? > > > > Try it and let us know :-) > > Well, I though there must be someone to _know_. At least the person who > decided to default to CONFIG_NOHIGHMEM on 2.0. > > 3.0 could be a whole different. Do you have the default kernel installed > or is this the FC 4 package?Using 2.6.12, that is the one make world grabs when doing install from source tar ball. Regards, Ted _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> The kernel configuration has: > > CONFIG_NOHIGHMEM=y > # CONFIG_HIGHMEM4G is not set > > What options should I set here? I would like to give up to about 1.5GB > to a domU. Why is highmem disabled by default? Any negative effects on > the stability, are there known problems?AFAIK, setting it to 4G Should Just Work. I don''t know of any problems with it and I think it is quite widely used. I don''t know why it is off by default, but possibly it is because it is off by default in the vanilla kernel (it is still off by default in vanilla, isn''t it?). -- ,^--^. ,-----. Never meddle in the affairs of angry cats, ( + + )----- ---'' for they are well-armed and quick to bite. / -- ) http://surreal.istic.org/ keyid 885b170d |_,-|_/--,_|-\_| I''m not complaining; I''m just commenting negatively. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Daniel Hulme wrote:>>The kernel configuration has: >> >>CONFIG_NOHIGHMEM=y >># CONFIG_HIGHMEM4G is not set >> >>What options should I set here? I would like to give up to about 1.5GB >>to a domU. Why is highmem disabled by default? Any negative effects on >>the stability, are there known problems? > > AFAIK, setting it to 4G Should Just Work. I don''t know of any problems > with it and I think it is quite widely used. I don''t know why it is off > by default, but possibly it is because it is off by default in the > vanilla kernel (it is still off by default in vanilla, isn''t it?).Ok, reasonable explanation. I will try as soon as I have time (probably not before two weeks) and report if it works for me (at least for the archives :-). Thanks! Best Regards, Michael Paesold _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users