Hi Arie, It happens every time, not just the first time, so I don't think its seek time
I am running as root Both machines are remote, so I can't see thrashing :D 2009/9/8 Arie Skliarouk <sklia...@gmail.com> > Try to measure disk seek time on both disks: > > time echo $(dd if=/dev/sda of=/dev/null count=1 bs=512; dd if=/dev/sda > of=/dev/null count=1 bs=1 skip=200049647116;) > > Replace the last number with size of the disk - several bytes (check using > fdisk -l). > The operation would give meaningful result only the first time you run it. > > If someone has better way to check disk seek speed, please share. > > Are you running the script as root? > Do you get the same slow results each time you run it or only the first > time? > Is there disk thrashing during startup? > > -- > Arie > > > > 2009/9/8 Noam Rathaus <no...@beyondsecurity.com> > >> Everything is on the /dev/sda >> >> And local >> >> That is not the answer... >> >> >> On Tue, Sep 8, 2009 at 3:28 PM, Gabor Szabo <szab...@gmail.com> wrote: >> >>> 2009/9/8 Noam Rathaus <no...@beyondsecurity.com>: >>> > Hi, >>> > >>> > I have two machines, their hardware is not identical, but their >>> installation >>> > is. >>> > >>> > One is a 3 years old DELL server, while the other is a 1 year old >>> server. >>> > >>> > One is running 2.6.26-2-686 while the other 2.6.30-1-686 >>> > >>> > What I am seeing is slow startup - emphasis on startup, the code works >>> fast >>> > once its running - of perl scripts >>> > >>> > Even the smallest perl script such as this: >>> > === >>> > #!/usr/bin/perl >>> > >>> > use lib '/usr/local/MySystem/lib'; >>> > >>> > use DB; >>> > >>> > === >>> > >>> > Take 7 seconds to start, in comparison to 0.030secods >>> > >>> > If I don't use the "use DB;" which my package >>> > >>> > It loads fast >>> > >>> > I am trying to figure out why, I checked the HD speeds via hdparam, the >>> > newer server is 1.5 times faster 103MB/sec >>> > >>> > I tried to see what libraries were being used, used strace, but I can't >>> see >>> > something "big" that is causing the delay. >>> > >>> > The "use DB;" can be replaced with any other "custom" library package I >>> > wrote, they all take 2-7 seconds to load, while on the other machine it >>> > takes negligible time >>> > >>> > Does someone have a "thread" to cling to? >>> > >>> >>> >>> A wide guess is that it is searching the @INC and on one system >>> @INC points to a slow disk maybe via NFS ? >>> >>> Gabor >>> >>> >> >> _______________________________________________ >> Linux-il mailing list >> Linux-il@cs.huji.ac.il >> http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il >> >> > > _______________________________________________ > Linux-il mailing list > Linux-il@cs.huji.ac.il > http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il > >
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