19.1 Understanding Volume Properties

Backup

The Backup attribute sets a flag to indicate to the backup software that the volume contains data you want to back up. Disable this flag if the volume is empty or if backing up the data is unnecessary. This backup flag is independent of the third-party backup system you use; your backup system might not recognize this option, even if you select it. The Backup attribute is enabled by default.

Compression

The Compression attribute activates file compression in NSS volumes. Compression can be activated at creation time only and this choice persists for the life of the volume. Data in the volume might be stored normally or in compressed form, depending on how frequently it is used. Compression parameters can be set at the server level to control compression behavior. For information, see Managing Compression on NSS Volumes.

Data Shredding

The Data Shredding attribute allows you to electronically overwrite deleted and purged data areas to prevent unauthorized users from using a disk editor to access purged files. You can specify the number of times (1 to 7) to shred data. For information, see Section 21.3, Using Data Shredding to Prevent Access to Purged Files.

Directory Quotas

The Directory Quotas attribute enables you to assign a maximum quota of space that a directory can consume. For information, see Managing Space Quotas for Volumes, Directories, and Users.

AD-enable the Volume

Choose this option to AD-enable the selected volume. For a volume (both NSS32 and NSS64) to be accessible to the AD users, it should be part of a pool that is AD media upgraded, and it should be AD-enabled.

Migration (to Third-Party Near-Line or Offline Storage)

The Migration attribute sets a flag that indicates to third-party software that this volume’s data can be migrated to near-line or offline storage media after it is inactive for specified lengths of time. This attribute requires third-party software to take advantage of the capability.

Modified File List

The Modified File List (MFL) attribute enables NSS to create a list of all files modified since the previous backup. The log is available only through third-party software.

Salvage Files

The Salvage Files attribute enables deleted files to remain on the volume until the Purge Delay time expires or until space is needed on the volume for other data. Until the Purge Delay time expires, the Salvage feature tracks the deleted files and allows the deleted files to be salvaged and restored. If space is needed, the oldest deleted files are purged to clear space. Salvage is enabled by default.

If the Salvage Files attribute is disabled, deleted files are purged immediately on deletion.

For information, see Section 24.0, Salvaging and Purging Deleted Volumes, Directories, and Files.

User Space Quotas

The User Space Quotas (user space restrictions) attribute enables you assign a maximum quota of space that a user’s data can consume across all directories in the volume.

For information, see Managing Space Quotas for Volumes, Directories, and Users.

Mount Point

Specify the mount point for the NSS volume, such as /media/nss/VOLA.

The default mount path for NSS volumes is /media/nss/volumename, where volumename is the name of the volume. You can optionally specify another path as the mount point.

This feature works only if the volume is mounted in its default location (/media/nss/volumename). For example, you have a volume VOL1 and the default mount point location is /media/nss/VOL1. For this volume, you have selected the option Allow Mount Point to be Renamed.

You renamed VOL1 to MYVOL, the default mount point after renaming becomes as /media/nss/MYVOL.

Lookup Namespace

NSS provides multiple name spaces for the volume: Long, UNIX, DOS, and Macintosh. The Lookup Namespace attribute sets the primary name space to use when you mount the volume, but all name spaces are available for use by various applications.

For NSS volumes, the Long name space is highly recommended because names on NSS are case insensitive by default. The UNIX name space supports case-sensitive naming.

For OES 2 SP1 and later, Long is also the default name space for NSS volumes. Using the Long name space as primary improves performance over using the UNIX name space, especially if you expect to store millions of files on the volume.

NCP tools require only the Long or UNIX be set as the primary name space. With DOS or Mac set as the primary name space, you cannot view or manage the volume from OES Remote Manager, and users are unable to map to the volume using NCP clients. If you use the Long or UNIX name space, the DOS and Mac name spaces are still available, but they are not the primary.

The UNIX name space supports some special characters that are not allowed in the Long name space, such as characters 0x01 through 0x07 and 0x10 through 0x1f. If you need to use these special characters in filenames, choose UNIX as the default name space.

If you change the name space for an existing shared volume by using NSSMU or the Storage plug-in for iManager, you must modify the load script for the pool cluster resource to add the name space to the ncpcon mount command for the volume. Otherwise, the cluster assumes the default name space for mounting the volume. You can do this by using the /opt=ns=<long|unix|dos|mac> switch in the ncpcon mount command.

For example, to specify the LONG name space, add the /opt=ns=long switch as follows:

ncpcon mount /opt=ns=long <VOLUMENAME>=<VOLUMEID>

For example, to specify the UNIX name space, add the /opt=ns=unix switch as follows:

ncpcon mount /opt=ns=unix <VOLUMENAME>=<VOLUMEID>