I have installed Xen on top of an Ubuntu Feisty Server Edition. The system has 4Gig of RAM. Feisty by default sets up a swap partition 2x~3x times the size of the RAM, which in this case ended up being nearly 10G. Is this much swap space necessary for running dom0? TIA, Tomoki Taniguchi _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Tomoki Taniguchi wrote:> I have installed Xen on top of an Ubuntu Feisty Server Edition. > The system has 4Gig of RAM. Feisty by default sets up a > swap partition 2x~3x times the size of the RAM, > which in this case ended up being nearly 10G. > > Is this much swap space necessary for running dom0? >Nahhh. A bit of swap is always good, because Linux keeps the RAM occupied almost to its limit with various things "just in case", and a sudden demand for RAM can overwhelm that before it can be paged out and freed up for other use (such as starting my OpenOffice when somebody''s busy compiling Xen and running a serious MySQL database under heavy load). And it''s a lot cheaper than buying a few gig of RAM for those rare occasions. But 10 Gig of RAM on a 4 Gig machine seems.... fairly excessive. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Yes that sound a lot too much. 1st point i would make is to pass dom0_mem=xxxxx where xxxxx is number of kilobytes to assign to dom0 (not including domU''s) 128 megabytes should be more than enough (xxxxx=128000). 2nd point as a general rule i find its then good to use same amount of swap space as i have ram in that case would be 128 megabytes. I have heard in the past it used to be suggested 2x ram for swap but that much is not often needed. In general a dom0 should not require so much ram because it doesn''t as a rule do anything but serve domU''s. 128 megabytes of each should be plenty. Tomoki Taniguchi wrote:> I have installed Xen on top of an Ubuntu Feisty Server Edition. > The system has 4Gig of RAM. Feisty by default sets up a > swap partition 2x~3x times the size of the RAM, > which in this case ended up being nearly 10G. > > Is this much swap space necessary for running dom0? > > > TIA, > Tomoki Taniguchi > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> Yes that sound a lot too much. 1st point i would make is to pass dom0_mem=xxxxxWhere this should be configured? _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Hi sorry did i miss out that part, it should be dome in the /boot/grub/menu.lst mine looks like this. title Xen 3.0.3-1-i386-pae / Debian GNU/Linux, kernel 2.6.18-4-xen-686 root (hd0,0) kernel /boot/xen-3.0.3-1-i386-pae.gz dom0_mem=64000 module /boot/vmlinuz-2.6.18-4-xen-686 root=/dev/hda1 ro console=tty0 module /boot/initrd.img-2.6.18-4-xen-686 savedefault Geoff shacky wrote:>> Yes that sound a lot too much. 1st point i would make is to pass dom0_mem=xxxxx >> > > Where this should be configured? > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Wow strnge formating going on here sorry again: title Xen 3.0.3-1-i386-pae / Debian GNU/Linux, kernel 2.6.18-4-xen-686 root (hd0,0) kernel /boot/xen-3.0.3-1-i386-pae.gz dom0_mem=64000 module /boot/vmlinuz-2.6.18-4-xen-686 root=/dev/hda1 ro console=tty0 module /boot/initrd.img-2.6.18-4-xen-686 Geoff Kirk wrote:> Hi sorry did i miss out that part, it should be dome in the > /boot/grub/menu.lst > mine looks like this. > > title Xen 3.0.3-1-i386-pae / Debian GNU/Linux, kernel > 2.6.18-4-xen-686 > root (hd0,0) > kernel /boot/xen-3.0.3-1-i386-pae.gz dom0_mem=64000 > module /boot/vmlinuz-2.6.18-4-xen-686 root=/dev/hda1 ro > console=tty0 module /boot/initrd.img-2.6.18-4-xen-686 > > savedefault > > > Geoff > > > shacky wrote: >>> Yes that sound a lot too much. 1st point i would make is to pass >>> dom0_mem=xxxxx >>> >> >> Where this should be configured? >> >> _______________________________________________ >> Xen-users mailing list >> Xen-users@lists.xensource.com >> http://lists.xensource.com/xen-users >> > > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Geoff Kirk wrote:> Yes that sound a lot too much. 1st point i would make is to pass > dom0_mem=xxxxx where xxxxx is number of kilobytes to assign to dom0 > (not including domU''s) 128 megabytes should be more than enough > (xxxxx=128000). 2nd point as a general rule i find its then good to > use same amount of swap space as i have ram in that case would be 128 > megabytes. I have heard in the past it used to be suggested 2x ram for > swap but that much is not often needed. In general a dom0 should not > require so much ram because it doesn''t as a rule do anything but serve > domU''s. 128 megabytes of each should be plenty.Alas! The RHEL 5 and thus the CentOS 5 Dom0''s fail to run virt-install or virt-manager without at lest 500 Meg of RAM available for Dom0. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Nice to know that, my dom0''s (dom0_mem=64000) are only PIII''s with 512 ram i must be just lucky i don''t use virt-manager i guess. Works just fantastic on debian-etch. Of course this is at home and not really working very hard. Geoff Nico Kadel-Garcia wrote:> Geoff Kirk wrote: >> Yes that sound a lot too much. 1st point i would make is to pass >> dom0_mem=xxxxx where xxxxx is number of kilobytes to assign to dom0 >> (not including domU''s) 128 megabytes should be more than enough >> (xxxxx=128000). 2nd point as a general rule i find its then good to >> use same amount of swap space as i have ram in that case would be 128 >> megabytes. I have heard in the past it used to be suggested 2x ram >> for swap but that much is not often needed. In general a dom0 should >> not require so much ram because it doesn''t as a rule do anything but >> serve domU''s. 128 megabytes of each should be plenty. > Alas! The RHEL 5 and thus the CentOS 5 Dom0''s fail to run virt-install > or virt-manager without at lest 500 Meg of RAM available for Dom0. > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Geoff Kirk wrote:> Nice to know that, my dom0''s (dom0_mem=64000) are only PIII''s with 512 > ram i must be just lucky i don''t use virt-manager i guess. Works just > fantastic on debian-etch. Of course this is at home and not really > working very hard. > > Geoff > > Nico Kadel-Garcia wrote: >> Geoff Kirk wrote: >>> Yes that sound a lot too much. 1st point i would make is to pass >>> dom0_mem=xxxxx where xxxxx is number of kilobytes to assign to dom0 >>> (not including domU''s) 128 megabytes should be more than enough >>> (xxxxx=128000). 2nd point as a general rule i find its then good to >>> use same amount of swap space as i have ram in that case would be >>> 128 megabytes. I have heard in the past it used to be suggested 2x >>> ram for swap but that much is not often needed. In general a dom0 >>> should not require so much ram because it doesn''t as a rule do >>> anything but serve domU''s. 128 megabytes of each should be plenty. >> Alas! The RHEL 5 and thus the CentOS 5 Dom0''s fail to run >> virt-install or virt-manager without at lest 500 Meg of RAM available >> for Dom0.You can use virt-manager for monitoring systems: for doing the libvirt based installer, though, whoosh! Lots of RAM, baby! CentOS 5 and RHEL 5 are serious RAM pigs. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users