As the title suggests, I tried the other day to provision database home 19c on my X8M system and it failed. I managed quickly to find what the issue is and it comes down to file permissions.

The Exadata Cloud Service X8M is using the new resource model so that you always provision 2 compute nodes and 3 storage cells (equivalent to a quarter rack) and then you scale out as much as you needed. If you haven't read my previous posts on provisioning and scaling I suggest you do that now.

Respectively I provisioned X8M and then added two more compute nodes, the operation was successful and I have database instances running across all nodes already. Then I decided to give the new 19c upgrade feature a try and that's where I ran into the error. Apparently the scale operation (or GI) did not set the correct permissions of the file above:

test-exacs-sfe4w1: -rw-rw---- 1 grid oinstall 174 Dec  7 15:49 /u01/app/oraInventory/ContentsXML/oui-patch.xml
test-exacs-sfe4w2: -rw-rw---- 1 grid oinstall 174 Dec  7 12:45 /u01/app/oraInventory/ContentsXML/oui-patch.xml
test-exacs-sfe4w3: -rw-r--r-- 1 grid oinstall 174 Nov 20 03:25 /u01/app/oraInventory/ContentsXML/oui-patch.xml
test-exacs-sfe4w4: -rw-r--r-- 1 grid oinstall 174 Nov 20 03:25 /u01/app/oraInventory/ContentsXML/oui-patch.xml

After setting the correct permissions of oui-patch.xml file the provisioning of database home 19c was successful. Thus, if you are provisioning 19c home on your Exadata Cloud Service make sure you check the permissions first. Again, that's not a rocket science but good to be available in the search engines should someone run into this problem and don't want to go the SR route.

You can find more information on home provisioning in these two files:

/var/opt/oracle/log/dummydb19000/clone/clone.log
/var/opt/oracle/log/dummydb19000/clone/clone-cmd.log

The clone-cmd.log file has the actual the error:

You can find the log of this install session at:
 /u01/app/oraInventory/logs/InstallActions2020-12-04_07-50-55PM/installActions2020-12-04_07-50-55PM.log
SEVERE:OUI-10094:Problem in saving inventory. Installation cannot continue. oracle.sysman.oui.patch.PatchException: java.io.FileNotFoundException: /u01/app/oraInventory/ContentsXML/oui-patch.xml (Permission denied)
[FATAL] OUI-10094:Problem in saving inventory. Installation cannot continue. oracle.sysman.oui.patch.PatchException: java.io.FileNotFoundException: /u01/app/oraInventory/ContentsXML/oui-patch.xml (Permission denied)

Later on I found a note in MOS on (almost) the same issue, for reference:

opatchauto apply Results java.io.FileNotFoundException: /ContentsXML/oui-patch.xml (Permission denied) Error in Non-OUI Nodes (Doc ID 2582139.1)

I raised SR asking the support to raise a bug but they will be updating the above note to include Exadata Cloud Service as well.