Review: HSM Toolkit 1.0
Product Information Requirements
Published by: FWB Software LLC
185 Constitution Drive, Suite A
Menlo Park, California 94025
Phone: (415) 463-3500
Fax: (415) 463-3558
Street Price: $69.99
Mac with a 68020 better processor
System 7.1 or higher.
Hard disk with 2 MB free for HSM TK.
At least 1 MB of free RAM.
A near-line storage device.
The Drive Space Problem
Today’s entry level drive is 1 GB in size and will probably become 2 GB within 18 months. Along with the increasing drive size are larger and larger applications that create larger and larger data files. The typical solution is to add another drive but no matter how many drives are added, there is a finite limit to drive space and/or disposable income. The solution is Hierarchical Storage Management (HSM), a system that automatically manages how and when data is moved onto a less expensive storage medium.
How Does HSM Work?
HSM is a management system that has the ability to move files along a hierarchy of storage devices so that the primary disk drive contains only the most frequently used files. The action of cleaning a storage device of old files is called grooming the device. The hierarchy of storage devices ranges from expensive devices such as fast hard drives, to less expensive and slower devices such as tape drives.
The HSM name implies the system has the intelligence to automatically migrate little-used data from the most expensive to the least expensive device. When files are migrated HSM typically leaves an alias on the original device that points to the new location of the files. When a file that has been moved is accessed, HSM will automatically demigrate a file from the slower device back to the faster device.
Another way to consider the storage hierarchy is in terms of on-line, near-line, and off-line storage. On-line storage devices are those that provide immediate access to data. Hard disks and RAM are the most common types of on-line storage. Near-line storage devices are those that provide slower access to data. Magneto-optical (MO) disks and network volumes are near-line storage devices. Off-line storage devices are the least expensive and slowest of the storage devices. Tapes are the most common off-line devices. Whereas MO disks can access data in a matter of seconds, accessing data on tape can take many minutes.
HSM complements, but is not a replacement for data backup. A data backup will help restore data after an accident or catastrophic failure of the storage device. The purpose of HSM is to manage data storage and administration.
HSM Toolkit (HSM TK)
HSM Toolkit 1.0 is FWB’s version of HSM for the Mac. It’s a decent 1.0 version of a program that implements basic HSM for certain groups of users. I’ll expand on that statement later.
Installing HSM TK is a simple procedure that only requires a few minutes. Initial use of HSM TK requires that you specify the source and destination volumes. The source volume is the volume to be groomed. Only one source volume can be specified. The destination can be almost any Finder-visible read/write device such as a SyQuest or AppleShare volume. Only a single destination volume can be specified. There are several other settings but the initial defaults will suit most users. After selecting the source and destination volumes HSM TK will begin to record your file usage in its own file migration database. HSM TK needs to maintain its own migration database because the Mac OS tracks only the time and date a file was created or modified and not when the file was last accessed. The initial defaults may cause you to wait several days or weeks before you notice HSM TK migrating files. If you don’t want to wait for HSM TK to do its work you can ask it to migrate particular files or folders immediately.
For finer control of the grooming process HSM TK has options to control the migration and demigration of files based on available disk space and last access.
The watermark rule allows you to specify when to start migrating files based on available disk space. For example, the default watermark value is 85%. When the source volume becomes 85% full HSM TK will migrate files until the volume capacity is 5% less than the watermark value.
The second method to control migration is by specifying the file age at which migration should occur. The default file age is 2 months. HSM TK will monitor its file migration database for files that have not been accessed for 2 months so unless you change the file age rule to something less that 2 months, you may not notice any activity for 2 months!
The migration/demigration time setting lets you control at what time you want HSM TK to do its work. The default setting is 20 minutes of idle which means HSM TK will start migrating or demigrating after 20 minutes of inactivity. Other choices allow you to specify at Shutdown time or after a particular time on a specific day of the week.
To save space on the destination volume data files, but not application files, can be compressed during migration. During normal operation the files are uncompressed when they are demigrated. The compressed files are in a slightly modified Stuffit format but the HSM Expander utility will decompress the files if want to access the files without demigrating them.
For finer control over individual files the anchor feature will allow you to specify files that will never be migrated automatically. For example, you may not want sensitive payroll files to be migrated to a server volume. The manual migrate option will force the immediate migration of files and folders, including any anchored files or folders.
Real World Test Results
After several weeks of use I came across no problems that could be attributed to HSM TK. On several occasions I changed the time and date on my Mac to past and future dates to test the robustness of the HSM migration database. I also rearranged the folder hierarchy of the migrated files on the destination volume to determine if HSM could locate the files for demigration. Even the addition of my favorite 15 Extensions didn’t stop HSM TK so I’ll have to give HSM TK an A+ for reliability.
The Final Word
HSM TK is a very decent version 1.0 of an HSM program. However it’s inability to handle more than one source or destination volume, or any off-line storage devices may limit its usefulness somewhat. Power users or professionals that generate large amounts of data may find HSM TK a convenient method of managing rarely used files. Although I didn’t test HSM TK with my NetWare 4.11 server, I can foresee how the tape backup on the NetWare server can provide the backup ability that’s required for a complete HSM/backup solution.
At the time of this writing, FWB has announced it’s intentions to replace HSM TK in May with Storage Wizard, an updated HSM product with enhanced archiving, automation and compression functions.