Reduces costs by slowing the proliferation of hard disks and backup systems. Labor costs are reduced because many routine jobs can be automated, and the effort to backup systems is greatly reduced. Since valuable data is stored on appropriate media and can be directed to secure media as needed, the potential for disasterous business interruptions is minimized.
Satisfies users because the system offers an "infinite hard disk." Management is satisfied because costs associated with growing data stores are greatly reduced. The SAM software manages the data storage so that the data the user needs is always available with minimum delay. No re-training of the user is required.
Data archives of virtually unlimited scope can be built at the least possible cost.
Archiving is not backing up.
Data that is archived with HSM is always available. Data
controlled by HSM need only be backed up once, and from then
on the backup copy is "refreshed" as needed. Essentially, HSM
removes most data from the backup process.
HSM does not require any action by users.
Since it is difficult or impossible to get users to back up on a
regular basis, it stands to reason that it is equally difficult to have
them identify data to be archived and do something about it. The
idea behind HSM is that the administrator would commit
particular data to an HSM system based on corporate objectives.
Temporary and "scratch" data will still likely reside on the user's
hard disk, where it will need to be backed up. By removing the
company's valuable data from user's hard disks, HSM makes it
unimportant whether a user backs up or not (it is still important to
the user).
Data archived by HSM is always available to the user, and with no change to the user's normal procedure. This means that no "user interface" or "GUI" is required (which would be an intrusive change to normal procedure). HSM software requires interfacing between the system administrator and the storage server, so the user interface and GUI features should be restricted to the administrator.
Access to archived data is fast.
Speed of access to archived data is always better than backup
packages. No explicit user command must be given to retrieve the
data, and data residing on on- or near-line media comes up within
seconds. It is up to the system administrator (or optionally, the
user) whether data accessed is moved ("staged") to the on-line
magnetic disk or is directly accessed from the archival media.
HSM is less expensive than backup.
The savings can be demonstrated by the labor savings (both by
administrators and users), the savings in media usage, and the
intangible (yet uncontested) value in protecting the data from
disaster. HSM is totally transparent, so users are working exactly
as before, with no re-training. How many other technologies can
boast that?
It is the HSM vendor's job to convey these benefits to end users who are deluged with claims by backup vendors that they have incorporated "HSM" or "migration" to their products, when the product functionality is really quite different.
Hidden Cost Savings of HSM Software
System administration costs are reduced by automating routine
tasks and eliminating the need to backup much of the data. Less
time is spent supporting users with backup questions or backup
failures, or in prompting users to do backups.
Storage space available to the network appears infinite. With SAM and removable media, the network grows simply by adding cartridges.
A disaster recovery plan is almost a given simply by installing HSM.
No retraining of users or "re-engineering" of current data organization is required.
Current facilities are used with much more effectiveness, as HSM relieves the pressure on hard disks, backup systems, budgets, and personnel.
The difference can be stated simply:
Once a file has been archived, its alternate copies exist for the life
of the file and need not be stored on any other medium including
on-line storage. The data of an archived file is, in general,
"immediately" available through the archive mechanism of SAM-
FS. This is because off-line archive storage is considered an
addressable extension of the primary on-line disk storage.
Conversely, backup systems only make a snapshot of the current state of the file system. Recovery of a file (usually due to loss) involves an extraction process which copies the file from the backup media on to on-line storage. Backup procedures are still required for an archive system. However, rather than copying data (the data space), only the structure of the file system (the name space) need be copied in the traditional manner.
With backup, many copies of the same file can exist, and it is up to the user to determine which one is the "current" version. This creates a situation where much waste can occur in terms of media use and labor. Errors in version control can create havoc with manufacturing or design operations.
HSM relieves much of the load on backup. By removing selected data from the backup process, users can backup in much less time (especially since much of the backup now consists of the name space only). There is no version control issue in a properly implemented HSM system.
Return to LSC's Home Page.
(C)1994 LSC, Inc. All Rights Reserved