Re: [zones-discuss] Memory reservation
Pascal Fortin wrote: > If you have a system with a fixed number of zones, you can distribute the > total > amount of memory to the zones except what you want to reserve. If you don't > know > how many zones you will have or on which system your zone will be run, you > can't > easily manage how many memory you will cap to your zone. Also, when you use > memory cap, you have to do it for each zone and it's a pretty workload when > you > have 800 zones in production. It could be better to have, let say, a kernel > parameter to reserve memory. It's a reverse thinking. The zones won't be > allowed > to go up to the memory cap but not beyond what it will be reserved for the > global zone. > > Thanks for the discussion we have, One RFE we have related to this is: 6543082 zonecfg should allow specification of some resources as percentage of system total I actually wrote the code for this a while back, but I haven't had time to finish the work to get it integrated. I was trying to do that as part of a larger effort, but maybe I'll try to get it putback as a standalone fix. The project for memory sets is: PSARC 2000/350 Physical Memory Control but since it requires a major rewrite of the VM system, it is unclear when this might be available. Thanks, Jerry ___ zones-discuss mailing list zones-discuss@opensolaris.org
Re: [zones-discuss] Memory reservation
If you have a system with a fixed number of zones, you can distribute the total amount of memory to the zones except what you want to reserve. If you don't know how many zones you will have or on which system your zone will be run, you can't easily manage how many memory you will cap to your zone. Also, when you use memory cap, you have to do it for each zone and it's a pretty workload when you have 800 zones in production. It could be better to have, let say, a kernel parameter to reserve memory. It's a reverse thinking. The zones won't be allowed to go up to the memory cap but not beyond what it will be reserved for the global zone. Thanks for the discussion we have, Pascal Jerry Jelinek a écrit : Pascal Fortin wrote: Hi Jerry, Thanks for your response. This is not overprovisioned system but you can have a bug somewhere that lead to use all memory and, of course, you have to correct it. But all other zones in the system will suffer from this situation and in consolidation context, it's annoying. As the zones are moving from one system to another, it's not so easy to use memory capping. This is why a reserved memory could be more intelligent and practical. I'd like to understand what issues you've seen with memory caps and zone migration. Can you explain your problem further and explain how memory sets would solve it? Thanks, Jerry -- Pascal FORTIN Services Account Manager Sun Microsystems France 13 avenue Morane Saulnier 78140 Velizy Villacoublay Phone x30401 / +33 1 34 03 04 01 Mobile +33 6 85 83 10 01 Email pascal.for...@sun.com ___ zones-discuss mailing list zones-discuss@opensolaris.org
Re: [zones-discuss] Memory reservation
Pascal Fortin wrote: > Hi Jerry, > > Thanks for your response. This is not overprovisioned system but you can have > a > bug somewhere that lead to use all memory and, of course, you have to correct > it. But all other zones in the system will suffer from this situation and in > consolidation context, it's annoying. As the zones are moving from one system > to > another, it's not so easy to use memory capping. This is why a reserved > memory > could be more intelligent and practical. I'd like to understand what issues you've seen with memory caps and zone migration. Can you explain your problem further and explain how memory sets would solve it? Thanks, Jerry ___ zones-discuss mailing list zones-discuss@opensolaris.org
Re: [zones-discuss] Memory reservation
Hi Jerry, Thanks for your response. This is not overprovisioned system but you can have a bug somewhere that lead to use all memory and, of course, you have to correct it. But all other zones in the system will suffer from this situation and in consolidation context, it's annoying. As the zones are moving from one system to another, it's not so easy to use memory capping. This is why a reserved memory could be more intelligent and practical. Regards, Pascal Jerry Jelinek a écrit : Pascal Fortin wrote: Hi all, I guess the answer is no but i want to have your opinion on this stuff. Is there a way to guarantee a minimum amount of memory for the global zone? This is to prevent all memory being catched by other zones and eventually you can't do anything to free this memory. Due to the shortage of memory, you can't even log in to the machine. I'm aware of memory capping but this is a little bit different. Feel free to share your thoughts about this stuff. We currently don't have a way to reserve a set of memory for a zone, so the best you can do is always set the memory caps on each zone to ensure that there is still plenty of memory left for the global zone. Can you describe the environment you're in where this won't be sufficient? Are these actively hostile zones? Is this system overprovisioned so that there is just not enough memory? Jerry ___ zones-discuss mailing list zones-discuss@opensolaris.org -- Pascal FORTIN Services Account Manager Sun Microsystems France 13 avenue Morane Saulnier 78140 Velizy Villacoublay Phone x30401 / +33 1 34 03 04 01 Mobile +33 6 85 83 10 01 Email pascal.for...@sun.com ___ zones-discuss mailing list zones-discuss@opensolaris.org
Re: [zones-discuss] Memory reservation
Pascal Fortin wrote: > Hi all, > > I guess the answer is no but i want to have your opinion on this stuff. Is > there > a way to guarantee a minimum amount of memory for the global zone? This is to > prevent all memory being catched by other zones and eventually you can't do > anything to free this memory. Due to the shortage of memory, you can't even > log > in to the machine. I'm aware of memory capping but this is a little bit > different. > Feel free to share your thoughts about this stuff. We currently don't have a way to reserve a set of memory for a zone, so the best you can do is always set the memory caps on each zone to ensure that there is still plenty of memory left for the global zone. Can you describe the environment you're in where this won't be sufficient? Are these actively hostile zones? Is this system overprovisioned so that there is just not enough memory? Jerry ___ zones-discuss mailing list zones-discuss@opensolaris.org
[zones-discuss] Memory reservation
Hi all, I guess the answer is no but i want to have your opinion on this stuff. Is there a way to guarantee a minimum amount of memory for the global zone? This is to prevent all memory being catched by other zones and eventually you can't do anything to free this memory. Due to the shortage of memory, you can't even log in to the machine. I'm aware of memory capping but this is a little bit different. Feel free to share your thoughts about this stuff. Regards, Pascal -- Pascal FORTIN Services Account Manager Sun Microsystems France 13 avenue Morane Saulnier 78140 Velizy Villacoublay Phone x30401 / +33 1 34 03 04 01 Mobile +33 6 85 83 10 01 Email pascal.for...@sun.com ___ zones-discuss mailing list zones-discuss@opensolaris.org
