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Delphix

NFS Operations May Stall Due to DNS Lookup Timeouts (KBA9053)

 

KBA

KBA# 9053

 

Issue

VDB operations such as start, provision, refresh and rewind may stall with the Oracle alert log reporting that the database is unable to lock a file due to no locks being available, as in the example below.

SQL> ORA-01565: error in identifying file '/provision/VDB1/datafile/spfile.ora'
ORA-27086: unable to lock file - already in use
Linux-x86_64 Error: 37: No locks available
Additional information: 10

Prerequisites

The Delphix engine is running version 6.0 or later.
The Delphix engine hosts VDBs that access their data files via NFS, for example Oracle, SAP ASE, or AppData.

Applicable Delphix Versions

Click here to view the versions of the Delphix engine to which this article applies
Major Release All Sub Releases
6.0 6.0.0.0, 6.0.1.0, 6.0.1.1, 6.0.2.0, 6.0.2.1, 6.0.3.0, 6.0.3.1, 6.0.4.0, 6.0.4.1, 6.0.4.2, 6.0.5.0, 6.0.6.0, 6.0.6.1, 6.0.7.0, 6.0.8.0, 6.0.8.1, 6.0.9.0, 6.0.10.0, 6.0.10.1, 6.0.11.0, 6.0.12.0, 6.0.12.1, 6.0.13.0

Resolution

The cause of the timeouts during reverse DNS lookups of the target host IP address(es) should be investigated in order to prevent further occurrences of this issue.

To work around this issue, entries for the target hosts can be added to the hosts file of the Delphix engine using the steps listed in the document below.  This avoids the need to look up the details via DNS but would need to be actively maintained in the event that the names or IP addresses of the target hosts change or if target hosts are added or removed.

Manually Adding an IP Address to URL/Hostname Mappings (KBA8150)

This issue will be resolved in a future Delphix version via bug DLPX-80112.

Troubleshooting

Please engage Delphix Support for troubleshooting assistance in the event that this issue is suspected.

 


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