Do you have an Apex Front end? 2009/5/15 Paweł Kotlarz <pkotla@xxxxxx> > Hello all. > > I have oracle 10.2.0.3 data warehouse database on 11.1.0.7 ASM with > asmlib. RHEL 4.7. Proliant DL585 G2 with MSA70 storage. > > The problem I face is an 'I/O hiccup'. The database can work properly > for a week or two and then suddenly keep stalling for no apparent > reason. Users complain that their selects take 2x or 3x more time. > vmstat shows I/O activity (bi, bo colums) for half a minute and for > another half a minute shows no activity (bi and bo columns equal to 0) > and a number of processes waiting for I/O (procs/b column). strace on an > oracle process waiting for I/O shows it is waiting for a completion of > 'read' call. The only thing that helps is rebooting the box. > > I can isolate the problem to specific disks using iostat. These disks > are the same on a day the problem occurs but they are different on > another occurrance of the problem. Storage / Linux admins do not see any > problem on their side. > > I have several one-off patches recommended by Oracle support: > > Bug 5452672: Hung database instance if linux kernel miss aio request > Bug 6656824: LNX-10204-TC6 SIGSEGV AT SKGFR_REAP64()+281, IN DBW0 > Bug 6087207: WARNING:ORACLE PROCESS RUNNING OUT OF OS KERNEL I/O RESOURCES > Bug 6882513 - MERGE LABEL REQUEST ON TOP OF 10.2.0.3 FOR BUGS 6801535 > 5576584 > Bug 5576584 (4880399): ASM PARALLEL READS PERFORMANCE NOT ACCEPTABLE > > I plan to upgrade to 10.2.0.4 but need first to sort out some hash join > bugs (yet unknown to Oracle) that break our large queries with ora-600 > errors. > > What would you recommend to do to narrow down the problem to Oracle / > ASM / asmlib / Linux / storage fault? > > Do you know of any other bugs that can show such a behaviour? > > Thanks. > > > Pawel Kotlarz > -- > //www.freelists.org/webpage/oracle-l > > > -- Howard A. Latham