Any network-attached storage (NAS) device can provide storage
for ordinary files that are created and used by Rational® ClearCase® (release
areas, for example, or the remote storage pools supported by Rational ClearCase hosts
running Linux® or the UNIX® system).
In addition, several NAS devices have been certified by IBM to provide
storage, when properly configured and used, for all VOB and view storage.
NAS devices provide data storage resources to other
hosts on a local area network by using a network file system protocol
such as the Network File System (NFS) on Linux or
the UNIX system, or on the Common Internet File
System (CIFS) on Windows®. Putting view and (especially)
VOB storage on a supported NAS device can provide several advantages:
- Enhanced scalability. VOB or view storage can grow well
beyond the physical limits typically imposed when the VOB or view
is stored on a Rational ClearCase server
host.
- Enhanced flexibility. Separating the server host from its
VOB or view storage simplifies the process of upgrading the server
host.
- Simplified administration. NAS devices often have enhanced
backup and restore features that can simplify backing up and restoring
VOBs and views. When you use the mkstgloc command
to create server storage locations on NAS devices, you can simplify
VOB and view creation and administration further.
- Simplified interoperation. Most certified NAS devices can
be configured to support interoperation among Rational ClearCase hosts
that run different supported operating systems. You do not need to
install additional cross-platform file-access software on Rational ClearCase client
or server hosts if you are using a NAS device to provide VOB and view
storage for a mixed network of Rational ClearCase computers
that run different supported operating systems. For more information,
see Cross-platform file-system access.
Note: Every certified NAS device must be configured to support remote
VOB or view databases. Configuration requirements for each certified
device are described in the online
IBM Rational ClearCase Platforms Guide. If you
do not configure a certified NAS device as described in that document,
any VOB or view data stored on that device is at risk. If you put
a VOB or view database on a NAS device that has not been certified
for this purpose, the data is at risk. In some cases, using a NAS
device for VOB or view storage can degrade
Rational ClearCase performance.
For more information, see
Server performance and NAS devices.
Special procedures may be required when creating, moving, backing
up, or restoring VOBs and views on NAS devices. For more information,
see Backing up critical Rational ClearCase data and Restoring critical Rational ClearCase data.