<div dir="ltr">Hi,<br><br>Interesting riddle...<br><br>2009/9/8 Noam Rathaus <span dir="ltr"><<a href="mailto:noamr@beyondsecurity.com">noamr@beyondsecurity.com</a>></span><br><div class="gmail_quote"><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div dir="ltr">The most notable difference is the read time on files (new HD)<br>0.047210 read(7, " <= 0)\n {\n $numLimit = 10;\n }\n\n "..., 4096)<br><br>Instead of (old HW)<br>
0.001462 read(6, "owItem = $1;\n\n my $RowItems = $s"..., 4096) = 4096<br><br>That is 40 times slower (it is the same file being opened)<br></div></blockquote><div><br>What is the filesystem used on the machines? Do they have similar mount flags (no_atime or such)?<br>
If both are ext2/3, compare "tune2fs -l /dev/sda1" on them.<br>Try to mount both filesystems using noatime and compare timings then.<br><br>Full disk might affect fragmentation or placement of the files and thus require long seeks. As atime needs to be updated (or journal log), buffering in memory would not help.<br>
Test write speed of the disks.<br> <br>--<br>Arie<br></div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div dir="ltr"><br>I have no idea why there is such a difference<br>
<br>hdparm on the old:<br>
hdparm -t /dev/sda<br><br>/dev/sda:<br> Timing buffered disk reads: 190 MB in 3.02 seconds = 62.87 MB/sec<br><br>hdparm on the new:<br># hdparm -t /dev/sda<br><br>/dev/sda:<br> Timing buffered disk reads: 314 MB in 3.01 seconds = 104.22 MB/sec<br>
<br><div class="gmail_quote">On Tue, Sep 8, 2009 at 3:02 PM, Noam Meltzer <span dir="ltr"><<a href="mailto:tsnoam@gmail.com" target="_blank">tsnoam@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div dir="ltr">Did you try to check with strace ?<br><br><div class="gmail_quote"><div class="im">2009/9/8 Noam Rathaus <span dir="ltr"><<a href="mailto:noamr@beyondsecurity.com" target="_blank">noamr@beyondsecurity.com</a>></span><br>
</div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div><div></div><div>
<div dir="ltr">Hi,<div><div></div><div class="h5"><br><br>I have two machines, their hardware is not identical, but their installation is.<br><br>One is a 3 years old DELL server, while the other is a 1 year old server.<br>
<br>One is running 2.6.26-2-686 while the other 2.6.30-1-686<br>
<br>What I am seeing is slow startup - emphasis on startup, the code works fast once its running - of perl scripts<br><br>Even the smallest perl script such as this:<br>===<br>#!/usr/bin/perl<br><br>use lib '/usr/local/MySystem/lib';<br>
<br>use DB;<br><br>===<br><br>Take 7 seconds to start, in comparison to 0.030secods<br><br>If I don't use the "use DB;" which my package<br><br>It loads fast<br><br>I am trying to figure out why, I checked the HD speeds via hdparam, the newer server is 1.5 times faster 103MB/sec<br>
<br>I tried to see what libraries were being used, used strace, but I can't see something "big" that is causing the delay.<br><br>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<br>
<br>Does someone have a "thread" to cling to?<br><br>Thanks,<br>Noam Rathaus<br></div></div></div>
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