[Ocfs-devel] Re: [Ocfs-users] ocfs issues with 9.2.0.3

Tue Nov 11 19:02:31 CST 2003

I wuold try without powerpath (mount the /dev/sdXX devices directly)
I would try the qlogic driver that comes with red hat (if you are using
the emc/dell provided one) 
and try again

pwoerpath hurts performance a lot with certain drivers.
the qla driver that we have seen being installed at customers was linked
without himem io and without varyio which is just plain wrong.

so, also you shoudl talk to oracle support since this clearly is a real
setup... this is just as time permits on this list so don't want to set
expectactions that this will always get instant responses.

also if you run e.24 as kernel, go to at least e.25

so my advice

red hat e.25
qlogic driver from addon/qla2xxx/ from Red Hat -not anyone elses

and try direct on the device instead of empower

On Tue, Nov 11, 2003 at 01:34:10PM -0500, Karthik Ramadoss wrote:
> Wim,
> 
> 1- which device driver, and are you using powerpath or securepath
> 	we have had at least 3 customers that were pointing at us for
> 	perofrmance and it ended up being the driver in most cases
> 
> We are using Powerpath. 
> 
> 2- how many filesystems (ocfs) do you have
> 
> Just one ocfs on 4 volumes carved out of EMC SAN (u01, u02, u03, u04).
> 
> 3- if you archive, do yuou arechive to 1 filesystem from all nodes,
> into
> a seperate directory or the same dir.
> 
> We are archiving from the 2 nodes to different directories in different
> volumes in ocfs. (Node1 to /u02 & Node2 to /u04).
> 
> Thanks,
> Karthik
> 
> On Tue, Nov 11, 2003 at 12:08:46PM -0500, Karthik Ramadoss wrote:
> > Jim,
> > 
> >       I appreciate your response. I understand we are NOT supposed
> to
> > use non-Oracle files on ocfs and we are not.
> > But, the Scenario#2 occurs even when I resize a tablespace or create
> a
> > tablespace from an sqlplus session in Oracle.
> > 
> >       Sometimes, the archiver process hangs with 'D' state and puts
> > lots of the below messages in the alert log.
> > ARC1: Evaluating archive   log 3 thread 2 sequence 3
> > ARC1: Unable to archive log 3 thread 2 sequence 3
> >       We are using a common archive destination for both instances
> and
> > thats a directory on ocfs. I wonder if that could be causing the
> lockup
> > for this particular archive issue. But that still doesnt explain why
> > any major change to datafile like resizing or creating through
> Oracle
> > would hang.
> >       With our 11.5.9 - 9.2.0.3 setup we dont have Oracle-Managed
> Files
> > implemented as you may know, 11.5.9 comes with 
> > almost 400 seeded datafiles. 
> > 
> > Thanks,
> > Karthik
> > 
> > >>> "Fennacy, Jim" <jimf at HDCSI.com> 11/11/2003 11:47:37 AM >>>
> > I had the chance to talk with one of the OCFS developers recently.  
> > I have not experienced scenario #1, so I cannot speak to that.
> > 
> > But for scenario #2...
> > 
> > OCFS v1.9 does NOT support non-Oracle managed files on the OCFS
> > partition.
> > Scenario #2 you indicated will occur.  Oracle's UTL_FILE package
> does
> > not
> > count as "Oracle managed files", so you cannot create/read/write
> files
> > using
> > UTL_FILE package.  I was told to NEVER put any files on OCFS.  Let
> > Oracle do
> > all the work.  At best there will be speed degradation; at worst the
> > system
> > will become unusable.
> > 
> > OCFS v2.0 will (1) support installing a shared Oracle Home on OCFS
> and
> > (2)
> > increased performance.  But only Oracle-managed files can exist on
> > OCFS.
> > 
> > OCFS v2.x will support any file on OCFS.  This version will be
> > released
> > along with Oracle 10G, but may be able to work with Oracle 9i.
> > 
> > I was also told that non-Oracle managed files on OCFS v1.9 and v2.0
> > only
> > affects Linux, technically.  Windows does not have the same problem.
> 
> > But
> > Oracle will not support it.
> > 
> > We are doing OFCS on a 2-node Redhat AS2.1 cluster at two different
> > sites.
> > We had a large number of non-Oracle files on OCFS for a couple
> months
> > and
> > experienced repeated problems.  Since moving all the files off OCFS
> > the
> > problems have disappeared.
> > 
> > Hope this helps.
> > 
> > -----Original Message-----
> > From: Karthik Ramadoss [mailto:krama at asugroup.com] 
> > Sent: Nov 11, 2003 8:19 AM
> > To: ocfs-devel at oss.oracle.com; ocfs-users at oss.oracle.com 
> > Subject: [Ocfs-users] ocfs issues with 9.2.0.3
> > 
> > 
> > I am starting to see a few issues with OCFS and 9.2.0.3 RAC on
> > redHat Linux AS 2.1. Wondering if there is anyone out there
> > experiencing similar issues... 
> > 
> > a few pointers to the issues..
> > 1. OCFS read/write performance is way lower than a read/write to a
> raw
> > device.. i can give you some comparison numbers..
> > 
> > 2. Writes to shared disk with ocfs would get locked up by one
> server..
> > it doesnt have to even be an oracle process.. just a file copy will
> > lock up the directory and the other server trying to access the same
> > directory in the shared disk will just hang (os process has a state
> > 'D').... the only way to free
> > this up is to unmount the shared disks from the other server.. even
> > killing the
> > process which is hanging doesnt work (kill -9).. 'strace -p' also
> > hangs
> > and obviously the process is waiting on io..
> > 
> > Is there anyone else experiencing this kind of issue? 
> > 
> > Thanks
> > Karthik Ramadoss
> > Oracle Apps DBA 
> > The ASU Group
> > 
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