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Operating Systems
Solaris
Disk IO high. What to fix ?
Post 302858553 by Smiling Dragon on Monday 30th of September 2013 07:31:10 PM
09-30-2013
defunct processes seldom contribute to high IO wait times anyway. (Although they do suggest something is wonky, even Solaris doesn't usually have 18 of those things floating around after such a short uptime (half a year isn't long).
First identify if it's a tuning problem, a rubbish IO subsystem, or a rubbish application.
Is it so slow when the applications are not running? (ie bare OS, nothing else in memory)
Is it slow if you dd a few gigs of /dev/urandom out to a temp file on the disk?
If it's slow even without the app, see if the performance varies between the two disks, look for faults on the slower one if they differ a lot. Look for something wrong with the interface card if it's both the same.
If it's slow when the app runs, try to identify what process is spending all it's time in iowait and start there.
If these are not local disks (ie SAN perhaps), check your block sizes are sensible, exact multiples of each other, check for excessive contention on the fabric switch, yell at your SAN admin some - it's always their fault
First identify if it's a tuning problem, a rubbish IO subsystem, or a rubbish application.
Is it so slow when the applications are not running? (ie bare OS, nothing else in memory)
Is it slow if you dd a few gigs of /dev/urandom out to a temp file on the disk?
If it's slow even without the app, see if the performance varies between the two disks, look for faults on the slower one if they differ a lot. Look for something wrong with the interface card if it's both the same.
If it's slow when the app runs, try to identify what process is spending all it's time in iowait and start there.
If these are not local disks (ie SAN perhaps), check your block sizes are sensible, exact multiples of each other, check for excessive contention on the fabric switch, yell at your SAN admin some - it's always their fault
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LEARN ABOUT XFREE86
install-solaris
install-solaris(1M) install-solaris(1M) NAME
install-solaris - install the Solaris operating system SYNOPSIS
install-solaris install-solaris invokes the Solaris Install program. Depending on graphical capability and available memory at the time of invocation, install-solaris invokes either a text-based installer or a graphical installer. The following minimum requirements for physical memory dictate which features are available during installation: For SPARC machines: 128 MB Minimum physical memory for all installation types 128 MB Minimum physical memory required for windowing system 384 MB Minimum physical memory required for graphical-based installation For x86 machines: 256 MB Minimum physical memory for all installation types 256 MB Minimum physical memory required for windowing system 512 MB Minimum physical memory required for graphical-based installation In some cases, even if the minimum physical memory is present, available virtual memory after system startup can limit the number of fea- tures available. install-solaris exists only on the Solaris installation media (CD or DVD) and should be invoked only from there. Refer to the for more details. install-solaris allows installation of the operating system onto any standalone system. install-solaris loads the software available on the installation media. Refer to the for disk space requirements. Refer to the for more information on the various menus and selections. See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Availability |SUNWcdrom (Solaris instal- | | |lation media) | +-----------------------------+-----------------------------+ |Interface Stability |Evolving | +-----------------------------+-----------------------------+ pkginfo(1), install(1M), pkgadd(1M), attributes(5) It is advisable to exit install-solaris by means of the exit options in the install-solaris menus. 23 Sep 2005 install-solaris(1M)