Well they were running some instances of Oracle DB and JBoss on the machine and they tuned their memory usage so one would not eat up too much memory, preventing the other from running normally...
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Srija Sent: Friday, September 24, 2010 3:45 PM To: Red Hat Enterprise Linux 5 (Tikanga) discussion mailing-list Subject: Re: [rhelv5-list] Tuning parameter drop_caches Thanks everybody by answering my queries. I am also thinking in the same way that using "drop_caches" is not the solution rather it is dangerous. ###to "clear the memory" and found some other solution. :) Would you pl. let me know what is the solution you have :) Thanks again to all of you. --- On Fri, 9/24/10, Langley, Morgan (GE Capital) <[email protected]> wrote: > From: Langley, Morgan (GE Capital) <[email protected]> > Subject: Re: [rhelv5-list] Tuning parameter drop_caches > To: "Red Hat Enterprise Linux 5 (Tikanga) discussion mailing-list" > <[email protected]> > Date: Friday, September 24, 2010, 1:40 AM > I can confirm this, drop_caches > caused one of our RHEL 4 servers to crash. After this > experience, the application admin refrained from asking us > to "clear the memory" and found some other solution. :) > > Morgan > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] > On Behalf Of Corey Kovacs > Sent: Thursday, September 23, 2010 11:14 PM > To: Red Hat Enterprise Linux 5 (Tikanga) discussion > mailing-list > Subject: Re: [rhelv5-list] Tuning parameter drop_caches > > drop_caches is _not_ a tuning parameter, rather it's a > tuning tool. > You should _never_ do this on a production machine as very > bad things > can happen. > > > It's supposed to be used to _reset_ a systems mem to > a zero point in > order to allow you to make changes and evaluate there > effect, or debug > a leak or what have you. > > -C > > > On Thu, Sep 23, 2010 at 9:22 PM, Kyle O'Donnell <[email protected]> > wrote: > > you shouldn't *need* to do this at all. > > > > This gives a nice overview: > > > > http://www.linuxatemyram.com/ > > > > And if your devs don't believe have them try for > themselves using: > > > > http://www.linuxatemyram.com/play.html > > > > --kyleo > > > > On Thu, 23 Sep 2010 13:03:55 -0700 (PDT), Srija > > <[email protected]> > wrote: > >> Hi , > >> > >> In one of your xen guest ,one application is > running and is consuming > >> much memory, > >> so almost every alternate day they ask to reboot > the server. > >> > >> One of our admin suggested to use the following > command. > >> > >> free && sync && echo 3 > > /proc/sys/vm/drop_caches && free > >> > >> I was googling and there are mixed comments. Some > are advising it is > >> good , some are not. > >> > >> I was thinking that rather applying 'echo 3' , may > be 'echo 1' will be > >> good. > >> > >> As, > >> > >> To free pagecache: > >> > >> * echo 1 > /proc/sys/vm/drop_caches > >> > >> To free dentries and inodes: > >> > >> * echo 2 > /proc/sys/vm/drop_caches > >> > >> To free pagecache, dentries and inodes: > >> > >> * echo 3 > /proc/sys/vm/drop_caches > >> > >> Any advice will be really appreciated. Also do you > think when we will > >> execute the command, before that the application > is needed to be > >> stopped. > >> > >> Thanks in advance. > > > > _______________________________________________ > > rhelv5-list mailing list > > [email protected] > > https://www.redhat.com/mailman/listinfo/rhelv5-list > > > > _______________________________________________ > rhelv5-list mailing list > [email protected] > https://www.redhat.com/mailman/listinfo/rhelv5-list > > _______________________________________________ > rhelv5-list mailing list > [email protected] > https://www.redhat.com/mailman/listinfo/rhelv5-list > _______________________________________________ rhelv5-list mailing list [email protected] https://www.redhat.com/mailman/listinfo/rhelv5-list _______________________________________________ rhelv5-list mailing list [email protected] https://www.redhat.com/mailman/listinfo/rhelv5-list
