As I understand it, a domain is tied to a specific CPU on startup, and if it can be changed, it can only be changed manually. Is that right? Is it possible to have xen (or xend) check at regular intervals and move a domain to another physical CPU depending on current load? James ------------------------------------------------------- This SF.net email is sponsored by: IT Product Guide on ITManagersJournal Use IT products in your business? Tell us what you think of them. Give us Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out more http://productguide.itmanagersjournal.com/guidepromo.tmpl _______________________________________________ Xen-devel mailing list Xen-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/xen-devel
> As I understand it, a domain is tied to a specific CPU on startup, and > if it can be changed, it can only be changed manually. Is that right?Yup, it''s changed manually using an xm command (probably "xm pincpu [dom] [cpu]" but I''ve never used it and could be wrong ;-).> Is it possible to have xen (or xend) check at regular intervals and move > a domain to another physical CPU depending on current load?Currently this isn''t done but it''s perfectly feasible. Sensible options are: 1) Have an scheduler in Xen that will migrate domains about at run time. 2) Have the load balancer task in Xend. 2 is possibly the easiest to do and arguably the most flexible since it makes it easy to provide pluggable balancing policy modules. 1 would make sure that CPUs remain idle for the minimum time possible. It''s possible that one (or both) of these solutions will get implemented at some stage, although (I suspect) not in time for 2.0 which is looking pretty imminent. I don''t know of anybody local who''s volunteered to do this, however. Cheers, Mark> > > ------------------------------------------------------- > This SF.net email is sponsored by: IT Product Guide on ITManagersJournal > Use IT products in your business? Tell us what you think of them. Give us > Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out more > http://productguide.itmanagersjournal.com/guidepromo.tmpl > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/xen-devel------------------------------------------------------- This SF.net email is sponsored by: IT Product Guide on ITManagersJournal Use IT products in your business? Tell us what you think of them. Give us Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out more http://productguide.itmanagersjournal.com/guidepromo.tmpl _______________________________________________ Xen-devel mailing list Xen-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/xen-devel
> > As I understand it, a domain is tied to a specific CPU on startup, and > > if it can be changed, it can only be changed manually. Is that right? > > Yup, it''s changed manually using an xm command (probably "xm pincpu [dom] > [cpu]" but I''ve never used it and could be wrong ;-).Yes, that works.> > Is it possible to have xen (or xend) check at regular intervals and move > > a domain to another physical CPU depending on current load? > > Currently this isn''t done but it''s perfectly feasible. Sensible options are: > 1) Have an scheduler in Xen that will migrate domains about at run time. > 2) Have the load balancer task in Xend.Alternatively you could do it with a small external program. This would poll either xend to get load stats for each domain, or could use libxc directly. It would then talk to xend to re-pin appropriate domains. A nice simple modular piece of functionality that would be easy to maintain and modify. -- Keir ------------------------------------------------------- This SF.net email is sponsored by: IT Product Guide on ITManagersJournal Use IT products in your business? Tell us what you think of them. Give us Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out more http://productguide.itmanagersjournal.com/guidepromo.tmpl _______________________________________________ Xen-devel mailing list Xen-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/xen-devel
Hi, my pysical HD is mounted on the logical sda1. When i try to mount the loopback on something else than sda1, xm complains. With: disk = [ ''phy:loop0,xda1,w'', ''phy:sda1,sda1,r'' ] root = "/dev/xda1 ro" I get error msg: >>error begin VFS: Cannot open root device "xda1" or unknown-block(2,0) Please append a correct "root=" boot option Kernel panic: VFS: Unable to mount root fs on unknown-block(2,0) >>error end Does Xen deny use of anything else than logical sda1 for HD? When my physical HD is sda1, how can I use another logical drive for my loopback? To save space I want to read-only mount my pysical HD from the loopbacks. (If I try to mount sda1 now, I mount the loopback, not the pysical HD) Cheers, Rune
> Hi, my pysical HD is mounted on the logical sda1. When i try to mount > the loopback on something else than sda1, xm complains. > > With: > disk = [ ''phy:loop0,xda1,w'', ''phy:sda1,sda1,r'' ] > root = "/dev/xda1 ro"Why not just use sda2, sdb1, or hda1? I think we did away with xda because no-one was using it. Should we should put it back? Ian ------------------------------------------------------- This SF.net email is sponsored by: IT Product Guide on ITManagersJournal Use IT products in your business? Tell us what you think of them. Give us Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out more http://productguide.itmanagersjournal.com/guidepromo.tmpl _______________________________________________ Xen-devel mailing list Xen-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/xen-devel
> With: > disk = [ ''phy:loop0,xda1,w'', ''phy:sda1,sda1,r'' ] > root = "/dev/xda1 ro" > > I get error msg: > >>error begin > > VFS: Cannot open root device "xda1" or unknown-block(2,0) > Please append a correct "root=" boot option > Kernel panic: VFS: Unable to mount root fs on unknown-block(2,0)The xda devices got removed. Any sd* or hd* device node should work instead though. Did you realise you can now specify file:/path/to/file as the source device instead of running losetup manually and using phy:loop0? HTH, Mark> >>error end > > Does Xen deny use of anything else than logical sda1 for HD? When my > physical HD is sda1, how can I use another logical drive for my > loopback? > > To save space I want to read-only mount my pysical HD from the > loopbacks. > (If I try to mount sda1 now, I mount the loopback, not the pysical HD) > > Cheers, > Rune------------------------------------------------------- This SF.net email is sponsored by: IT Product Guide on ITManagersJournal Use IT products in your business? Tell us what you think of them. Give us Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out more http://productguide.itmanagersjournal.com/guidepromo.tmpl _______________________________________________ Xen-devel mailing list Xen-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/xen-devel
The sda2 worked out fine! I did not know that you can specify the file directly. This is good news tough:-) Thank you! Cheers, Rune On Oct 11, 2004, at 4:51 PM, Mark A. Williamson wrote:>> With: >> disk = [ ''phy:loop0,xda1,w'', ''phy:sda1,sda1,r'' ] >> root = "/dev/xda1 ro" >> >> I get error msg: >>>> error begin >> >> VFS: Cannot open root device "xda1" or unknown-block(2,0) >> Please append a correct "root=" boot option >> Kernel panic: VFS: Unable to mount root fs on unknown-block(2,0) > > The xda devices got removed. Any sd* or hd* device node should work > instead > though. > > Did you realise you can now specify file:/path/to/file as the source > device > instead of running losetup manually and using phy:loop0? > > HTH, > Mark > >>>> error end >> >> Does Xen deny use of anything else than logical sda1 for HD? When my >> physical HD is sda1, how can I use another logical drive for my >> loopback? >> >> To save space I want to read-only mount my pysical HD from the >> loopbacks. >> (If I try to mount sda1 now, I mount the loopback, not the pysical HD) >> >> Cheers, >> Rune > > > ------------------------------------------------------- > This SF.net email is sponsored by: IT Product Guide on > ITManagersJournal > Use IT products in your business? Tell us what you think of them. Give > us > Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out > more > http://productguide.itmanagersjournal.com/guidepromo.tmpl > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/xen-devel------------------------------------------------------- This SF.net email is sponsored by: IT Product Guide on ITManagersJournal Use IT products in your business? Tell us what you think of them. Give us Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out more http://productguide.itmanagersjournal.com/guidepromo.tmpl _______________________________________________ Xen-devel mailing list Xen-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/xen-devel
On Monday 11 October 2004 10:01 pm, Keir Fraser wrote:> > > As I understand it, a domain is tied to a specific CPU on startup, and > > > if it can be changed, it can only be changed manually. Is that right? > > > > Yup, it''s changed manually using an xm command (probably "xm pincpu [dom] > > [cpu]" but I''ve never used it and could be wrong ;-). > > Yes, that works. > > > > Is it possible to have xen (or xend) check at regular intervals and > > > move a domain to another physical CPU depending on current load? > > > > Currently this isn''t done but it''s perfectly feasible. Sensible options > > are: 1) Have an scheduler in Xen that will migrate domains about at run > > time. 2) Have the load balancer task in Xend. > > Alternatively you could do it with a small external program. This > would poll either xend to get load stats for each domain, or could use > libxc directly. It would then talk to xend to re-pin appropriate > domains. > > A nice simple modular piece of functionality that would be easy to > maintain and modify.This is the approach I like for sure. It''s much easier for someone like me (who isn''t a low-level systems programmer) to write scripts to do this sort of stuff. I think you''ll get much more community input this way too, and it doesn''t negate the possibility of building load-balancing capabilities in at a later date. I intend to use a combination of tools on the VMs themselves, reporting back to a central control script, and whatever auxilliary information I can get from Xen and dom-0''s proc. Paul ------------------------------------------------------- This SF.net email is sponsored by: IT Product Guide on ITManagersJournal Use IT products in your business? Tell us what you think of them. Give us Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out more http://productguide.itmanagersjournal.com/guidepromo.tmpl _______________________________________________ Xen-devel mailing list Xen-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/xen-devel