HP Enterprise Cluster Master Toolkit User Guide (5900-2131, December 2011)

these instances there may be cases where the application will need to be restarted and the
files reopened, as a switchover is a logical shutdown and restart of the CIFS Server.
• File Locks
File locks are not preserved during failover, and applications are not advised about any lost
file locks.
• Print Jobs
If a failover occurs when a print job is in process, the job may be printed twice or not at all,
depending on the job state at the time of the failover.
• Symbolic Links
Symbolic links in the shared directory trees may point to files outside of any shared directory.
If symbolic links point to files that are not on shared file systems, after a failover occurs, the
symbolic links may point to different files or to no file. Keeping the targets of all shared symbolic
links, synchronized with all nodes at all times, could be difficult in this situation.
Alternatives would either be to set wide links to "no", or to be sure that every file or directory
pointed to is on a shared file system.
• Security Files and Encrypted Passwords
Authentication is dependent on several entries in different security files. An important security
file is the user password file, smbpasswd. If your CIFS Server is configured with encrypted
passwords set to "yes", use an smbpasswd file. By default, this file is located in the path
/var/opt/samba/private but a different path may be specified via the smb passwd
file parameter.
Another important security file is secrets.tdb. Machine account information is among the
important contents of this file. Since this file will be updated periodically (as defined in
smb.conf by 'machine password timeout', 604800 seconds by default), HP recommends
that you locate secrets.tdb on a shared storage. As with the smbpasswd file, discussed above,
the location of this file is defined by the smb.conf parameter smb passwd file. For example,
smb passwd file = /var/opt/samba/shared_vol_1/private/smbpasswd will
result in the file/var/opt/samba/shared_vol_1/private/secrets.tdb .
To summarize, both the machine account file ( secrets.tdb) and the password file
(smbpasswd) should be put on shared storage.
• Username Mapping File
If the HP CIFS Server configuration is set to use a username mapping file, it should be located
on a shared file system. This way, if changes are made, all the nodes will always be up-to-date.
The username mapping file location is defined in smb.conf by the parameter 'username
map', example, 'username map = /var/opt/samba/shared_vol_1/username.map'. There is
no username map file by default.
• HP CIFS Server as a WINS Server
If HP CIFS Server is configured as a WINS server (that is, the WINS support parameter is set
to "yes"), the database /var/opt/samba/locks/browse.tdb will be stored.
If this file is not on a shared file system, when a failover occurs, there will be a short period
of time when all the WINS clients update the CIFS WINS server with their address. However,
if this short period of time to restore the WINS database is not acceptable, you can reduce
the period of time to restore the full WINS service.
To do so, configure /var/opt/samba/locks/browse.tdb to be a symbolic link to a
browse.tdb file on a shared file system. It is not recommended to put the entire
/var/opt/samba/locks directory on a shared file system, because the locking data may not
be correctly interpreted after a failover.
Special Notes 135