Known issues with the CIFS protocol after upgrading a Data Domain Restorer (DDR) to Data Domain Operating System (DDOS) version 5.7

Issues affecting access to shares on a DDR via the CIFS protocol. Note that some linked articles may not be visible to all users. For further assistance with any of these issues please contact your contracted support provider quoting details of this article.

SECTION 1 - GENERAL CIFS ISSUES:

After upgrading to DDOS 5.7 clients are unable to use the CIFS protocol to access shares which were created when the DDR was running DDOS 5.1 (or earlier):
Issue is addressed in DDOS 5.7.0.4 and later

After upgrading to DDOS 5.7 CIFS shares which were previously read only are now read/write via the CIFS protocol:
Issue is addressed in DDOS 5.7.1.0 and later
Further information: Data Domain: Configuring a CIFS Share

If CIFS debug logging is enabled CIFS log files may grow unexpectedly causing the /ddr/var file system to fill causing potential instability of the DDR:
Issue is addressed in DDOS 5.7.0.10 and DDOS 5.7.1.0 and later
Further information: https://support.emc.com/kb/463820

User or group information added to CIFS shares may be lost following an upgrade to DDOS 5.7:
Issue is addressed in DDOS 5.7.0.10 and DDOS 5.7.1.0

CIFS shares configured with an access list containing the /24 subnet may not be accessible after an upgrade to DDOS 5.7:
This is due to the design of the 'Likewise' software used for CIFS in DDOS 5.7.
This is improved/fixed in 6.0.0.9, ie. subnet is supported for the client access list.

The client list for CIFS shares can be truncated following an upgrade to DDOS 5.7 preventing some clients from accessing shared:
Issue is addressed in DDOS 5.7.2.0

DDRs are unable to join an active directory domain due to lsass timing out on the DDR (lsass timeout is only 30 seconds):
Issue is addressed in DDOS 5.7.1.0 and later (lsass timeout is increased to 90 seconds)
Further information: https://support.emc.com/kb/463747 

SECTION 2 - CIFS BACKUP ISSUES:
CIFS backups failures due to CIFS reaching exhausting the maximum number of supported TCP connections (600 connections)
Issue is addressed in DDOS 5.7.1.10 and later

Access to CIFS shares fails with "DDFM check share access: Unable to retrieve share information" due to the virtual memory size of the lsass process exceeding the configured soft limit:
Issue is addressed in DDOS 5.7.3.0 and later

CIFS backups are slow and may experience intermittent failures after upgrading to DDOS 5.7 due to commlib timeouts (messages similar to "Commlib error for async job" may be seen in /ddr/var/log/debug/cifs/cifs.log):
Issue is addressed in DDOS 5.7.1.10 and later

CIFS deamon (lwsmd) panics and failure of running CIFS backups/restores after upgrading to DDOS 5.7:
Issue is addressed in DDOS 5.7.1.0 and later

Poor performance/failure of CIFS backups in SMB2 enabled environments due to insufficient session timeout parameters after upgrading to DDOS 5.7:
This requires various registry parameters to be set on the CIFS client and increased buffer allocated within affected backup applications. Please contact your contracted support provider for further details.

CIFS backups fail due to permissions errors after upgrading to DDOS 5.7 caused by a backup being performed by a user other than the user originally used to create the backup folder:
Issue is addressed in DDOS 5.7.2.0 and later

SECTION 3 - DD ISSUES:
System is not accessible via GUI/SSH, due to DCERPC traffic causing hung SMS jobs
Issue is addressed in DDOS 5.7.2.10 and later.
Further information: https://support.emc.com/kb/487612

DDFS panics if the dd_xcacls utility is used to change file permissions and the system is subjected to subsequent CIFS workload:
To avoid this issue DDFS should be restarted after dd_xcacls is used (note that this will cause an interruption to running backups/restores):
# filesys restart

VNX data mover cannot access CIFS shares on DDR after the DDR is upgraded to DDOS 5.7

Space in /ddvar won't be reclaimed immediately after file removal via CIFS share
Work around is to run "cifs restart force" in CLI or perform more file operations on CIFS share for /ddvar. Fix is being discussed.
Further information: Data Domain - Space Running Low in /ddvar