Hi I did further tests, previously the results I posted was a test on AIX 6.1 and 11gR2, I have tested now with Linux x86-64 1. kill asm pmon 2. chown root.root asmdisk crsd process dies because it cannot access OCR (Disk Group not mounted): 2010-01-23 09:38:59.944: [ OCRASM][801350224]proprasmo: The ASM disk group OCR is not found or not mounted 2010-01-23 09:38:59.944: [ OCRRAW][801350224]proprioo: Failed to open [+OCR]. Returned proprasmo() with [26]. Marking location as UNAVAILABLE. 2010-01-23 09:38:59.944: [ OCRRAW][801350224]proprioo: No OCR/OLR devices are usable 2010-01-23 09:38:59.944: [ OCRASM][801350224]proprasmcl: asmhandle is NULL 2010-01-23 09:38:59.944: [ OCRRAW][801350224]proprinit: Could not open raw device 2010-01-23 09:38:59.944: [ OCRASM][801350224]proprasmcl: asmhandle is NULL 2010-01-23 09:38:59.945: [ OCRAPI][801350224]a_init:16!: Backend init unsuccessful : [26] 2010-01-23 09:38:59.945: [ CRSOCR][801350224] OCR context init failure. Error: PROC-26: Error while accessing the physical storage ASM error [SLOS: cat=8, opn=kgfoOpenFile01, dep=15056, loc=kgfokge ORA-17503: ksfdopn:DGOpenFile05 Failed to open file +OCR.255.4294967295 ORA-17503: ksfdopn:2 Failed to open file +OCR.255.4294967295 ORA-15001: diskgroup "OCR" ] [8] 2010-01-23 09:38:59.945: [ CRSD][801350224][PANIC] CRSD exiting: Could not init OCR, code: 26 2010-01-23 09:38:59.945: [ CRSD][801350224] Done. crsctl gives error: [root@grid1 ~]# /u01/grid/11.2.0/bin/crsctl stat res -t CRS-4535: Cannot communicate with Cluster Ready Services CRS-4000: Command Status failed, or completed with errors. however ASM and cssd is up and running So we have a complete different scenario, same test two different results in two operating system. Thanks! On Thu, Jan 21, 2010 at 2:36 PM, Bobak, Mark <Mark.Bobak@xxxxxxxxxxxx>wrote: > Yep, makes sense, I think. > > > > Clusterware starts, ASM serves up OCR and voting disk geometry, as it > relates to raw devices that make up your OCRDATA diskgroup. Clusterware > caches that info, no longer needs to talk to ASM for it. > > > > You do the damage, including changing ownership of devices that make up > OCRDATA diskgroup to root:root. But, clusterware processes run as root, so, > they can still read/write those raw devices. > > > > What happens if you chown the devices to root:root, then also chmod 000 all > those devices? > > > > -Mark > > > > *From:* oracle-l-bounce@xxxxxxxxxxxxx [mailto: > oracle-l-bounce@xxxxxxxxxxxxx] *On Behalf Of *LS Cheng > *Sent:* Thursday, January 21, 2010 7:44 AM > *To:* K Gopalakrishnan > *Cc:* Oracle Mailinglist > *Subject:* Re: Anyone tried kill ASM in 11gR2 RAC? > > > > Hi > > So even OCRDATA Disk Group is not mounted and the physical disks has > root.root instead of grid.oinstall ownership Clusterware will be up and > running? So basically you mean Clusterware does not need ASM to be up to > access the OCRDATA disks? > > My test was > > - kill ASM > - change asm disks (OCRDATA) from grid.oinstall to root.root > - check clusterware status which was up and running > > > > > > Thanks > > On Thu, Jan 21, 2010 at 1:38 PM, K Gopalakrishnan <kaygopal@xxxxxxxxx> > wrote: > > Clusterware failure will happen _only_ when it can not acess the > physical devices (disk timeout in css) and shutting down ASM does not > revoke the access to disks. In your case clusterware _knows_ the > location of ocr/voting information in ASM disks and it can continue > reading/writing even ASM instance is down. > > -Gopal > > > > > > On Thu, Jan 21, 2010 at 2:51 AM, LS Cheng <exriscer@xxxxxxxxx> wrote: > > Hi > > > > I was doing some cluster destructive tests on RAC 11gR2 a few days ago. > > > > One of tests was kill ASM and see how does that affects Clusterware > > operation since OCR and Voting Disks are located in ASM (OCRDATA Disk > > Group). After killing ASM nothing happened as it was quicky started up > > again. So far so good. The next test was same test but changing the ASM > > Disks ownership so when ASM is restarted OCR Disk Group cannot be > accessed. > > Surprisingly ASM Was started up, Database Disk Group was mounted OCR disk > > Group obviously did not get mounted but then the Cluster was working > without > > any problems. > > > > So how is this happening? Doesnt Clusterware need to write and read to > > Voting Disk every second? I was expecting a Clusterware failure in the > node > > but everything worked just as everything were ok. > > > > Thanks! > > > > -- > > LSC > > > > > > >