I have a server running Centos 4.7 32bit. Will moving from 4Gig of RAM to 8Gig do any good? Since its 32bit I assume it will only be able to address the first 4Gig not? When I installed CentOS I did not do anything special to enable using more then 4Gig if thats required. Exim, spamassassin and Clamd seem to be the biggest load on this machine. My biggest bottle neck is disk I/O anyway. Wish I had installed CentOS 5.x 64bit way back when but some of the software I was using at time listed support for it as beta. Matt
2008/12/5 Matt <lm7812 at gmail.com>:> I have a server running Centos 4.7 32bit. Will moving from 4Gig of > RAM to 8Gig do any good? Since its 32bit I assume it will only be > able to address the first 4Gig not?As long as you are using a SMP kernel you can use up to 64GB of RAM (though each proccess can only address 4GB of this). So if you can find any trace of "SMP" in the uname (grep is your friend) then it should work fine.
>> I have a server running Centos 4.7 32bit. Will moving from 4Gig of >> RAM to 8Gig do any good? Since its 32bit I assume it will only be >> able to address the first 4Gig not?> As long as you are using a SMP kernel you can use up to 64GB of RAM > (though each proccess can only address 4GB of this). So if you can > find any trace of "SMP" in the uname (grep is your friend) then it > should work fine.I have this: [root at srvr ~]# rpm -qa | grep kern kernel-smp-2.6.9-78.0.8.EL glibc-kernheaders-2.4-9.1.103.EL kernel-utils-2.4-14.1.117 kernel-2.6.9-78.0.8.EL [root at srvr ~]# [root at server ~]# uname -a Linux XXX 2.6.9-78.0.8.ELsmp #1 SMP Wed Nov 19 20:05:04 EST 2008 i686 i686 i386 GNU/Linux Matt
Hi, Tell me how much is the swap space you assigned and also you can use below commands to trace out the cause of such huge I/O.Also are using SAN or local storage?.I don't think so you need explanation for below commands.Run all the commands and redirect it to some file and send it to the list. Normally there is no need to fine tune any parameter to upgrade memory on centos 4.7 32 bit, because i am running centos production with 8GB of physical memory but with only 4GB of swap space(not twice the physical ram normaly people use causing huge I/O while using swap memmory because system have to read cylinders and tracks of 8GB takes long time compared to 4GB of swap space) while true ; do (ps -eo pcpu,pid,user,args |sort -k1 -r |head -10 >> /root/sys-reports/top10-cpu-utilzn) ; sleep 2 ; done sar -u 2 10000000 > /root/sys-reports/sar.txt mpstat -P ALL 5 | tee mpstat.txt top -b -i |tee top.txt vmstat -m 5 > vmstat.txt iostat -x 5 >> iostat.txt Regards, pap On Sat, Dec 6, 2008 at 5:22 AM, Matt <lm7812 at gmail.com> wrote:> I have a server running Centos 4.7 32bit. Will moving from 4Gig of > RAM to 8Gig do any good? Since its 32bit I assume it will only be > able to address the first 4Gig not? When I installed CentOS I did not > do anything special to enable using more then 4Gig if thats required. > Exim, spamassassin and Clamd seem to be the biggest load on this > machine. My biggest bottle neck is disk I/O anyway. > > Wish I had installed CentOS 5.x 64bit way back when but some of the > software I was using at time listed support for it as beta. > > Matt > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos >
On Wed, 2008-12-10 at 10:56 -0600, Matt wrote:> > Yes follow up to previous mail. That would be correct for those two. My > > opinions do not change however, I just saw the mail where it did not > > work because he has V4.x and needs to use grub.conf. > > In grub.conf I have this: > > --- > #boot=/dev/sda > default=0 > timeout=5 > splashimage=(hd0,0)/grub/splash.xpm.gz > hiddenmenu > title CentOS (2.6.9-78.0.8.ELsmp) > root (hd0,0) > kernel /vmlinuz-2.6.9-78.0.8.ELsmp ro root=/dev/VolGroup00/LogVol00 > initrd /initrd-2.6.9-78.0.8.ELsmp.img > title CentOS (2.6.9-78.0.8.EL) > root (hd0,0) > kernel /vmlinuz-2.6.9-78.0.8.EL ro root=/dev/VolGroup00/LogVol00 > initrd /initrd-2.6.9-78.0.8.EL.img > --- > > I just add elevator=deadline above default or something?Like this: kernel /vmlinuz-2.6.9-78.0.8.ELsmp ro root=/dev/VolGroup00/LogVol00 elevater=deadline And this change will be for System Wide.