Any info on what COMMANDS , parameters Values , switches to use for =
Enabling
it=20
on Compaq Tru 64 UNIX (Digital Unix) ver 4.0 G ?=20
=20
-----Original Message-----
From: K Gopalakrishnan [SMTP:kaygopal_at_yahoo.com]
Sent: Monday, September 04, 2000 1:39 PM
To: Multiple recipients of list ORACLE-L
Subject: Re: Optimal hard disk layout for Oracle
Hi !
Basically 'forcedirectio' bypasses the OS buffer cache and
talks directly to the disk. This increases the performance since
there is no 'middle man' during the IO.
This is HIGHLY recommended for redo logs.
In this case the OS buffer cahce is bypassed.
Regards,
K Gopalakrishnan
Bangalore, INDIA
> -----Original Message-----
> From: Figueiredo, Pedro [SMTP:PFigueiredo_at_europeantelecom.at]
> Sent: Monday, September 04, 2000 5:50 PM
> To: Multiple recipients of list ORACLE-L
> Subject: RE: Optimal hard disk layout for Oracle
>=20
> Hi,
>=20
> Well, basically it's a mount option that indicates how the OS manages =
the
> filesystems. The "default" uses OS buffering.=20
> If you specify direct IO, Oracle will perform a most direct device =
access
> as
> you don't have two layers of buffering.
> This redundacy consumes unecessary OS resources and will delay write
> access.
>=20
> The file system configuration on Sun Solaris is in /etc/vfstab.
>=20
> Don't use it on regular mount points. It's completely unnapropriate =
for
> normal I/O operations.
>=20
> Cheers
>=20
> Pedro Figueiredo
>=20
> -----Original Message-----
> Sent: segunda-feira, 4 de Setembro de 2000 7:48
> To: 'PFigueiredo_at_europeantelecom.at'
> Cc: 'ORACLE-L_at_fatcity.com'
>=20
>=20
>=20
> Pedro wrote - "Use forcedirectio on Oracle database devices"
> Give more Detail please on forcedirectio .=20
> Novice on O.S. here
>=20
>=20
> > -----Original Message-----
> > From: Figueiredo, Pedro [SMTP:PFigueiredo_at_europeantelecom.at]
> > Sent: Saturday, September 02, 2000 8:05 AM
> > To: Multiple recipients of list ORACLE-L
> > Subject: RE: Optimal hard disk layout for Oracle
> >=20
> > Hi,
> >=20
> > I believe Raid 5 is not very recommended with OLTP environments.=20
> > If you can use Raid 0 + 1 in a cluster solution it would be the =
ideal
> > solution.
> > Do some more research on the subject...
> >=20
> > If you have the possibility, use raw devices (at least) for the =
redo log
> > files.
> > Use forcedirectio on Oracle database devices (Sun Solaris =
terminology,
> > other
> > platforms should have similar possibility). No need to have both =
Oracle
> > and
> > OS buffering disk writes...
> >=20
> > Best regards
> >=20
> > Pedro Figueiredo
> >=20
> > -----Original Message-----
> > Sent: s=E1bado, 2 de Setembro de 2000 1:50
> > To: Multiple recipients of list ORACLE-L
> >=20
> >=20
> > Hi,
> > Since Temp and Rollbacks are almost all writes you may want to put =
them
> on
> > a
> > mirror set rather than Raid 5. There is a bit of a write penalty =
but
> not
> > a
> > major one.
> >=20
> > _Ernie
> > ----- Original Message -----
> > To: "Multiple recipients of list ORACLE-L" <ORACLE-L_at_fatcity.com>
> > Sent: Friday, September 01, 2000 6:08 PM
> >=20
> >=20
> > > Hi!
> > >
> > > We are about to get a new database server and my supervisor wants =
me
> to
> > > specify the hard disk layout. It is a given that we wanna go with =
RAID
> > 5.
> > So
> > > here is what I'm thinking about:
> > >
> > > Disk 1: Operating system + Oracle software
> > > Disk 2: Online Redo Logs
> > > Disk 3: Online Redo logs (mirrored)
> > > Disk 4: archived redo logs
> > > Disk 5-8: Oracle data files (i.e data + index tablespaces, temp
> > tablespaces,
> > > rollback segments)
> > >
> > > Disks 1-4 will be 'stand-alone' disks (i.e. no RAID or =
mirroring).
> Disks
> > 5-8
> > > will be in a RAID 5 array.
> > >
> > > Do you think it would be beneficial to add like another disk =
(e.g.
> place
> > > rollback segments or temp tablespace on a separate disk)?
> > >
> > > Any input would be appreciated.
> > >
> > > Thanks,
> > > Helmut
> > >
> > > --
> > > Author: Helmut Daiminger
> > > INET: hdaiminger_at_vivonet.com
> > >
> > > Fat City Network Services -- (858) 538-5051 FAX: (858) =
538-5051
> > > San Diego, California -- Public Internet access / Mailing =
Lists
> > > =
> > > To REMOVE yourself from this mailing list, send an E-Mail message
> > > to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and =
in
> > > the message BODY, include a line containing: UNSUB ORACLE-L
> > > (or the name of mailing list you want to be removed from). You =
may
> > > also send the HELP command for other information (like =
subscribing).
> > >
> >=20
> > --=20
> > Author: Ernest Simard
> > INET: simard_at_sonoma.edu
> >=20
> > Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051
> > San Diego, California -- Public Internet access / Mailing =
Lists
> > =
> > To REMOVE yourself from this mailing list, send an E-Mail message
> > to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
> > the message BODY, include a line containing: UNSUB ORACLE-L
> > (or the name of mailing list you want to be removed from). You may
> > also send the HELP command for other information (like =
subscribing).
> > --=20
> > Author: Figueiredo, Pedro
> > INET: PFigueiredo_at_europeantelecom.at
> >=20
> > Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051
> > San Diego, California -- Public Internet access / Mailing =
Lists
> > =
> > To REMOVE yourself from this mailing list, send an E-Mail message
> > to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
> > the message BODY, include a line containing: UNSUB ORACLE-L
> > (or the name of mailing list you want to be removed from). You may
> > also send the HELP command for other information (like =
subscribing).
> --=20
> Author: Figueiredo, Pedro
> INET: PFigueiredo_at_europeantelecom.at
>=20
> Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051
> San Diego, California -- Public Internet access / Mailing =
Lists
> --------------------------------------------------------------------
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Received on Wed Sep 06 2000 - 01:26:09 CDT
