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Unix Operating Systems Software Linux

Monitor Linux Performance With The Tools At Hand 27

Posted by timothy from the i-t-b-w-t-c-l dept.
Jan Stafford writes "Need to monitor Linux performance without purchasing a pricey diagnostic package? Try these simple, built-in command line tools. This article was written by site expert and author (Rapid Application Development with Mozilla) Nigel McFarlane."
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Monitor Linux Performance With The Tools At Hand More

Monitor Linux Performance With The Tools At Hand

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  • Historic.. (Score:5, Informative)

    by noselasd ( 594905 ) on Monday April 19, 2004 @07:27PM (#8910761)
    Most utilities mentioned are really great, but mostly realtime stats
    sometimes it's nice to see historic view on the machine as well.
    sysstat [wanadoo.fr] does just that.
    Now if only I can remember the thing that also use that statistics do
    draw graphs (with gnuplot iirc.) Anyone ?

    • Re:Historic.. (Score:5, Interesting)

      by Monster Zero ( 58806 ) on Monday April 19, 2004 @07:43PM (#8910920) Homepage
      Ganglia [sourceforge.net] Distributed Monitoring System is a nice tool for monitoring lots of systems, I use it to keep an eye on 66 servers. My current template has plots for Current Cluster CPU/MEM/Beowulf Queue, Cabinet Temperature, Free Disk Space for both RAID units, then shows the utilization of each of the 64 nodes. Its fairly customizable and works great. Shows hour/day/week/month/year plots selected by a drop down menu.

      It uses RRDTool [rrdtool.com] to create the plots - very nice.

    • Re:Historic.. (Score:4, Interesting)

      by sydb ( 176695 ) * <michael@NospAm.wd21.co.uk> on Monday April 19, 2004 @07:44PM (#8910933)
      Is there anything Free around to give per-process historical information a la BMC Patrol ("Draw me a graph of memory utilisation over the last 4 hours for PID 3325, and show me how much of it was in real memory and how much was in swap"). OK the graph is a nice to have, the data would suffice.

      Yeah, while true; do; ps -Fp3325 >> data.txt;sleep 1;done but I'm looking for something... Enterprise... I hate that word.
      • And then if you know Perl, you can always use one of the nifty graphics packages [cpan.org] like GD to create your graphs.

        Parse the datafile, plot your lines, and write the .png file. It's been a while since I've used these types of packages myself, but I remember the usage being almost trivial.

        Have fun.

        wbs.
        • Yes I would be happy doing that. It's just when you speak to people who use the big proprietary Enterprise monitoring suites they kinda scoff at a quick and dirty perl script. Anyway, for my purposes I will indeed probably knock something up in Perl.

  • disk performance? (Score:2, Offtopic)

    by menscher ( 597856 )
    How about hints for improving disk performance? I've got a raid array that does 100M/s reads, 80M/s writes under Win2k3 Server, but only 40M/s reads, 80M/s writes under RHEL 3.0. Obviously something is screwy with the linux read speeds, but we can't figure out why.

    I won't even start on our network performance problems, which are around 15M/s transfers (our network is capable of 100M/s).

    • I won't even start on our network performance problems, which are around 15M/s transfers (our network is capable of 100M/s).

      When you are saying M/s do you mean Megabit or Megabyte? 15MBps (megabyte per second) is pretty close to 100Mbps (Megabit per second.) Perhaps you are just getting the opposite (bit instead of byte) of what you are expecting in Linux?

      Maybe this is not the case, but I thought I would throw that out there just in case. Also, 100Mbps network cards don't always go 100Mbps. I've seen so
      • By M/s I mean MiB/s.
        By MiB/s I mean mebibytes per second.
        By mebibyte I mean 2^20 bytes.
        By byte I mean 8 bits.

        I hope that clears things up.

        (Our network is gigE, before someone tries explaining that 100Mb/s fast ethernet can't do 100M/s transfers.)

    • If it is an option for your situation, you should at least investigate a migration to kernel 2.6.x. The IO system is MUCH faster, as is thread allocation. You should see a fairly significant increase in RAID performance, and least for striping. You should also make sure DMA/32 bit mode is enabled on the drives, not all drivers will set this automatically. I'm sure you've checked these, just a mention though.

      As far as the network, it sounds like the driver is setting it to 100Mb mode instead of 1000Mb mode.
      • This is for a production server, so we'd prefer to avoid 2.6.x if possible (it doesn't seem to have stabilized quite yet).

        We're using a hardware raid (16 SATA drives that present themselves to the host as a single SCSI drive), which I think rules out the DMA/32 issue (that's IDE-only, right?). In any case, we're getting twice the read performance under Windows 2003 Server without hardware changes.

        The network is definitely at 1000Mb mode. I can even get it to benchmark at 940Mb using iperf (both TCP a

        • The hardware support is constantly changing between 2.6.x releases, but if you have the ability to test it, I highly recommend it. The IO scheduling is vastly improved. If you find a 2.6 kernel that supports your hardware and tests without mishap, stick with it and don't upgrade unless you have to.

          If you would prefer to stick with a 2.4.x kernel, you still have other options. Besides checking for updated SCSI drivers, you should check out the man page for 'blockdev'. Tuning your drive read-ahead can improv
    • The absolute first thing I would check with network is that if you are connected to a full duplex switch set the card to full duplex in modules.conf . Yes shit is supposed to autonegotiate but it never does.
  • 1. Setup a Linux web server
    2. Host an interesting story on Slashdot with large JPEGs.
    3. Post the story on Slashdot
    4. Watch your server being Slashdotted!
  • Maybe someone can answer this. I primarily use Gnome at home, and like it's system monitor for CPU and memory statistics. However, it only seems to work locally. Is there anyway to get it to display statistics for remote computers, possibly using something like RPC.statd (internal network, so insecurity isn't as much of an issue)?

    I know at work, I can use Solaris' perfmon tool to monitor our Linux server's current stats, but I can't seem to find anything like that for Linux on the client side. Anyone k
  • # find /proc | xargs cat

  • innacurate (Score:5, Insightful)

    by Danny Rathjens ( 8471 ) <slashdot2.rathjens@org> on Monday April 19, 2004 @11:08PM (#8912866)
    No offense, but this story is a joke. Did he even read the man pages for those utilities? The 'stat' in those tools names stand for 'statistics' not 'status'. And don't even get me started on stupid statements like "linux never swaps" and "If paging activity happens all the time, buy more RAM"

    These utilities are explained better in the man pages themselves or the various system administration guides and howtos at the linux documentaion project. [tldp.org]

    Oh yeah, and he is missing one of the best tools for this type of thing: namely 'sar', the system activity reporter, which is enabled by default on all redhat distros. (I have an xpostit note dedicated to all the flags to sar for various things)

    As for the graphing/monitoring questions people are asking in other posts; look for tools like nagios and mrtg and sysmon and mon or just search freshmeat.net. It's quite a common task which has been done many ways. My personal monitoring/graphs are perl scripts I wrote to fetch stats via ssh which I plug into mrtg.

  • The version iostat I have on RH Linux doesn't give you disk IO in bytes/s or MB/s. Have to work it out from the blocks/sec. Where the man says a block is of indeterminate size.

    Haven't figured out how to use netstat or some other built-in command to check the bandwidth usage for each network interface. I had to write a little snippet of perl to do that. Any suggestions?

    Seems a lot easier to do stuff like that on FreeBSD or even Windows 2000.

  • Test Tools (Score:4, Informative)

    by frobisch ( 630854 ) on Tuesday April 20, 2004 @07:53AM (#8914960)
    This is a good summary of available performance/test tools for Linux:
    Linux Test Tool Matrix [sourceforge.net]

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