Re: rman backup slow
- From: Prasad <p4cldba@xxxxxxxxx>
- To: ORACLE-L <oracle-l@xxxxxxxxxxxxx>
- Date: Fri, 30 Jan 2009 20:45:46 -0800
my apologies for the late response. To answer this . not it is not a new
database . it has been in production since last couple of years. it hosts a
application which has lot of LONG RAW data . it is right now 170GB . out of
which the LONG RAW table only occupies 80GB. The RMAN backup is taken
connected to recover catalog . The backup goes to disk . right now the
cursor_sharing is set to similar . The most significant wait I see is disk
async i/o . This is a solaris server with vxfs and it do not support async
i/o .
The puzzling factor is the select on x$dual which just sits silently for
hours. and the entire backup duration goes beyond 10 hour .
This is what we are planning to do increase the db_writer_process from 1 to
4 and set the disk_asynch_io to false ( i gues the default is TRUE) .
would appreciate your thoughts on this change .
because of the sensitivity of the application ( it is a highly visible
production database) it is a bit hard to find time to take a no catalog
backup and also do any tracing experiment . but i guess it seems
unavoidable .
hopefully I didnt miss to provide any information asked. please feel free to
let me know if any further information will assist finding solution.
Thanks again .
thanks
Prasad
>
>
> On Jan 30, 2009, at 1:10, Prasad <p4cldba@xxxxxxxxx> wrote:
>
> All,
>
> we have a 170G db on 9.2.0.7(solaris 9) . and I see that it currently is
> taking nearly 10 hour+ to do a rman backup . when I see this in grid
> control I see the rman session keeps waiting on this sql .
>
> SELECT
> TO_CHAR(SYSDATE,:"SYS_B_0",:"SYS_B_1"),TO_CHAR(SYSDATE,:"SYS_B_2",:"SYS_B_3"),
> TO_CHAR(SYSDATE,:"SYS_B_4",:"SYS_B_5") FROM X$DUAL
>
> anyone has any similar situation . appreciate any suggestion.
>
> Thanks in advance
>
> thanks
> Prasad
>
>
>
>
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