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

Tue Nov 11 13:34:10 CST 2003

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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