On Mar 31, 2008, at 5:49 PM, Craig Simpson wrote:
> The Volumes below pretty much explain their purpose.
>
> What I am running into is my DBA's say that they are not getting the
> read/write times that I see via vxstat.
>
> What are "AVG TIME(ms) READ WRITE" ???
>
> These mean the time it takes to
om: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of
Sebastien DAUBIGNE
Sent: Tuesday, April 01, 2008 7:57 AM
Cc: veritas-vx@mailman.eng.auburn.edu
Subject: Re: [Veritas-vx] vxstat data Questions
vxstat displays statistics collected by VxVM ; VxVM doesn't "see"
filesystem
the circle the beginning and the end are common"
> ~ Heraclitis (540-480BC)
>
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> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED] On Behalf Of Sebastien
> DAUBIGNE
> Sent: Tuesday, April 01, 2008 7:57 AM
> Cc:
~ Heraclitis (540-480BC)
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Sebastien
DAUBIGNE
Sent: Tuesday, April 01, 2008 7:57 AM
Cc: veritas-vx@mailman.eng.auburn.edu
Subject: Re: [Veritas-vx] vxstat data Questions
vxstat displays statistics collected by VxVM ; VxVM doesn'
Title: RE: [Veritas-vx] vxstat data Questions
vxstat displays statistics collected by VxVM ; VxVM doesn't "see"
filesystem management
Application Layer <= Oracle statistics
Filesystem Layer <== VMM statistics (vmstat)
2008 5:01 AM
To: veritas-vx@mailman.eng.auburn.edu
Subject: Re: [Veritas-vx] vxstat data Questions
Don't forget de filesystem layer : Unless you use direct I/O or
rawdevices, filesystem cache management will add extra latency that will
be counted by Oracle as I/O service time : Oracle sends
Don't forget de filesystem layer : Unless you use direct I/O or
rawdevices, filesystem cache management will add extra latency that will
be counted by Oracle as I/O service time : Oracle sends I/O via
read/write/pread/pwrite/aoiread/aiowrite syscalls which are at last
manager by the filesystem
Even though we all love to think that our database Engineers do not know
much about OS / hardware, sometimes their concerns are very real.
This is how I check my FS to see if it has issues:
1. Run "vxstat -r" to reset all statistic information. Ask DBA to increase
the load on a FS
2. Run vxtrace o
