32bit kernel, right?. Probably it's the kernel remaping mem. PAE is quite slow. It's an old tale ;).
On 11/30/09, tho...@equinox.homelinux.org <tho...@equinox.homelinux.org> wrote: > Hi all, > > this some kind of Off-Topic since it has nothing to do with LFS at all. I > send this to this list because I know that there are quite a lot geeks and > experienced people out there who may have a hint for me. > > Have you ever seen a machine which has too much RAM installed? We have a > brand new HP (DL380G6) server here with 48G RAM installed. It has an p410i > and a p800 SAS controller connected to a MSA70 with 1TB usable disk space. > There are 2 Quad-Core-Xeon (X5560) with hyperthreading (a total of 16 CPUs). > > As an OS there is s SuSE SLES10 installed and as DB-Software (because of > which we have this machine) Oracle10g. > > The problem: > When we create a file which is 32GByte large (for instance using dd > if=/dev/null of=test.dat...) the copy process runs very fast up to round > about 29-30GB slows down quite immediatly and the workload increases up to > loadavg=35 or so. It finally results in a non-responding machine where we > can only press the reset-button. > > What we did: > Adding the mentioned 30GB plus the rest what the OS itself is using it > adds up to quite exact 32GB. We removed 6 of the 12 RAM modules (every has > 4GB) so that the machine now has less that 32GB RAM (exact 24GB). The dd > command runs quite fast until the file was created and nothing special is > seen on the machine - everything worked as expected. > > Do you have an idea what the 32GB-limit could be? Or what could make the > machine to behave the way it does? > > Our next step will be to test that all with the 64-bit stuff but it should > work on 32bit too, isn't it? > > Any ideas? > > Thank you! > > Thomas > > -- > http://linuxfromscratch.org/mailman/listinfo/lfs-dev > FAQ: http://www.linuxfromscratch.org/faq/ > Unsubscribe: See the above information page > -- Ismael Luceno -- http://linuxfromscratch.org/mailman/listinfo/lfs-dev FAQ: http://www.linuxfromscratch.org/faq/ Unsubscribe: See the above information page
