Hi Armin, For Linux without accurate tweaks of kernel behavior, it's safer to limit memory for buffers even more, say, 1/2. That is due to noticeable consumption of memory by internal OS buffering.
In addition, I should warn you that SSD's lifetime under any database application can be smaller than expected, depending on OS and drivers. That's due to the nature of file I/O in databases. Some smart drivers try to balance numbers of writes to individual blocks --- a new version of file is written on blank space, not on place that is already occupied by the file or its previous copy. They promise even more sophisticated logic in the future (say, if a big movie is written only once to the disk and it occupies half of device whereas second half of space is nearly out of resource then the movie will be placed in heavily used half and frequently changed data will reside in almost new blocks used for the movie before). That tricks do not work if file exists continuously, like database file, and changes are frequent. Best Regards, Ivan Mikhailov OpenLink Software http://virtuoso.openlinksw.com On Thu, 2009-10-22 at 13:51 +0100, Hugh Williams wrote: > Hi Armin, > > But all your system memory ie 32GB will not be available as the system > itself and any other processes running on the machine will also > require memory to function. In the Virtuoso performance docs it is > recommended NumberOffBuffers be set 2/3 to 3/5 of system RAM: > > > http://docs.openlinksw.com/virtuoso/rdfperformancetuning.html > > So you need to reduce the setting to at least something less than the > currently available memory which the Linux "top" command would tell > you ... > > Best Regards > Hugh Williams > Professional Services > OpenLink Software > Web: http://www.openlinksw.com > Support: http://support.openlinksw.com > Forums: http://boards.openlinksw.com/support > Twitter: http://twitter.com/OpenLink > > On 22 Oct 2009, at 11:54, Armin Nagel wrote: > > > Hi folks, > > > > are there any limitations in numbuffers in virtuoso? > > I have a machine with 32gb RAM and 8 Cpu cores. > > 120GB SSD HDD and running 64Bit Suse Linux. > > I installed Virtuoso OS 5.0.11. > > > > My calculation for numbuffers is: > > 30(gb ram) *1024(in mbyte) *1024(in kbyte) = 31457280K / 8K = 3932160 > > numbuffers > > > > When I try to start virtuoso I got following error: > > OpenLink Virtuoso Universal Server > > 18:24:17 INFO: Version 05.11.3039-pthreads for Linux as of Sep 28 2009 > > 18:24:17 INFO: uses parts of OpenSSL, PCRE, Html Tidy > > 18:24:18 ERROR: GPF: disk.c:1294 Cannot allocate memory for Database > > buffers, try to decrease NumberOfBuffers INI setting > > > > why does it not work? > > > > I want to load whole ontology datasets(27gb) into memory for > > performant > > queries. > > > > Thanks for any hints. > > > > > > -- > > Armin Nagel > > Softwareentwickler > > > > neofonie > > Technologieentwicklung und > > Informationsmanagement GmbH > > Robert-Koch-Platz 4 > > 10115 Berlin > > fon: +49.30 24627 257 > > fax: +49.30 24627 120 > > [email protected] > > http://www.neofonie.de > > > > Handelsregister > > Berlin-Charlottenburg: HRB 67460 > > > > Geschaeftsfuehrung > > Helmut Hoffer von Ankershoffen > > (Sprecher der Geschaeftsfuehrung) > > Nurhan Yildirim > > ________________________________ > > > > Die erste Web 2.0 Suchmaschine jetzt auf http://www.wefind.de . > > > > Unterwegs immer bestens informiert mit WeFind Mobile für iPhone und > > jetzt auch mit WeFind Mobile für Android: kostenloser Download im > > iTunes > > AppStore und im Android Market. > > > > ------------------------------------------------------------------------------ > > Come build with us! The BlackBerry(R) Developer Conference in SF, CA > > is the only developer event you need to attend this year. Jumpstart > > your > > developing skills, take BlackBerry mobile applications to market and > > stay > > ahead of the curve. Join us from November 9 - 12, 2009. Register now! > > http://p.sf.net/sfu/devconference > > _______________________________________________ > > Virtuoso-users mailing list > > [email protected] > > https://lists.sourceforge.net/lists/listinfo/virtuoso-users > > > ------------------------------------------------------------------------------ > Come build with us! The BlackBerry(R) Developer Conference in SF, CA > is the only developer event you need to attend this year. Jumpstart your > developing skills, take BlackBerry mobile applications to market and stay > ahead of the curve. Join us from November 9 - 12, 2009. Register now! > http://p.sf.net/sfu/devconference > _______________________________________________ > Virtuoso-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/virtuoso-users
