SUMMARY: T64U read/write performance/tuning

Russ_Fish_at_idx.com
Date: 04/15/05

  • Next message: Bhattacharya Dhritiman (ext): "Problem configuring Tape Robot."
    Date: Fri, 15 Apr 2005 14:54:57 -0700
    To: tru64-unix-managers@ornl.gov
    
    

    Thanks to David Knight (David.Knight@xxxxxxxxx.xxx) and Martin Rønde
    Andersen (martin.roende@xxxxxxxx.xxx) along with one other person whose
    email I cannot find.

    David suggested taking a look at disk writes across cluster nodes (I
    neglected to mention we are clustered). We have not done this as yet but
    will definitely do so. David also supplied a perl script that allows
    read/write stats for disks included in a clustered volume, and I've long
    suspected that some of our problems lie here.

    Martin noted that we may well be saturating the disks no matter which node they're on, so moving a disk to the other node may not prove useful.

    We also opened a ticket with HP, and after looking at our collect output, the engineer recommended changing an /etc/sysconfigtab parameter
    (ssm_threshhold) from 0 to 8388608. The collective memory indicates that
    this parameter was set to 0 at Oracle's suggestion. Anyway, once we
    changed the parameter (no reboot required), we were able to unzip and ls
    simultaneously without one process blocking the other. We are not seeing
    improved performance (adding weight to Martin's contention) but the
    presenting problem has been resolved.
     
    ----- Forwarded by Russ Fish/SEA/IDX1 on 04/15/2005 02:45 PM -----

    Russ Fish/SEA/IDX1
    03/28/2005 03:04 PM

    To
    tru64-unix-managers@ornl.gov
    cc

    Subject
    T64U read/write performance/tuning

    Hi all--

    This may be a newbie question but I'll throw it out anyway. I saw
    something odd on one of our ES45 5.1B HSG80 servers last night:

    1. I began unzipping a large file (Oracle export file) in a directory,
    running in the background.
    2. I attempted an 'ls' of the directory where the unzip was running.
    3. The ls did not return until the unzip had completed.

    This caused me to wonder (a) if others have seen this, (b) under what
    other circumstances it happens, and (c) there's something at the file
    system or AdvFS level (e.g. sysconfigdb changes) we can do about it.

    --Russ

    -----------------------------------------------
    IMPORTANT NOTIFICATION
    -----------------------------------------------
    The contents of this e-mail and its attachments are confidential and may be privileged. If you are not the intended recipient of this e-mail, please notify IDX immediately (by return e-mail to either the sender or security@idx.com), destroy all copies of this message along with any attachments and do not disclose, copy and/or distribute the contents. The views expressed in this message are those of the author and not necessarily those of IDX. In the absence of a prior written agreement with you authorizing commitments of IDX via e-mail, the above message shall not bind IDX, unless from a duly authorized officer of the company in a context indicating an intention to bind the company.

    This e-mail and its attachments are protected by copyright and other laws. © IDX Systems Corporation 2004. All rights reserved. IDX is a registered trademark of IDX Investment Corporation.


  • Next message: Bhattacharya Dhritiman (ext): "Problem configuring Tape Robot."

    Relevant Pages

    • Re: Hoxs64 v1.0.4.0 released
      ... > Awesome work, David. ... >> 1) Disk file support is expanded to include Vincent Joguin's FDI ... Standard track layout D64 files will save as normal. ...
      (comp.emulators.cbm)
    • Re: Who can provide me some help on how to eliminate delay and speed up the setup process.
      ... David wrote: ... >>it is hard for me to find out the exact places causing such delay. ... If it is just a startup problem, I would first look at the ... the disk reads with a disk re-org. ...
      (comp.programming)
    • Re: OT: W/XP PC HD Crashed
      ... David J Dachtera wrote: ... There are data recovery services but they charge high! ... If you are using a PCI bus disk controller, reseat the PCI card as well. ...
      (comp.os.vms)
    • Re: Using cipher.exe to wipe a disk
      ... This posting is provided "AS IS" with no warranties, and confers no rights. ... > Thanks David. ... >>> work with semi-sensitive client data. ... >>> could use my new WinXP Pro system to wipe the old disk. ...
      (microsoft.public.windowsxp.security_admin)
    • Re: Understanding I/O behaviour - next try
      ... Martin, ... I am very interested to check out your patch. ... they are a dozen patches from various sources. ... numbers for the disk case. ...
      (Linux-Kernel)