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Pieces Here, There and Everywhere -- What Is One To Do?

If Humpty-Dumpty Were A Disk Drive, Either Of These Utilities Could Put Him Back Together Again

De-Frag/X
Lund Performance Solutions
240 Second Ave. S.W.
Albany, Oregon 97321
Tel: 541.926.3800
Fax: 541.926.7723
E-mail: info@lund.com
WWW: www.lund.com

A multipurpose utility designed to help the HP 3000 system administrator manage disk space. De-Frag/X runs on MPE/iX version 4.0 and later. It enables you to analyze, balance, condense, defragment and fragment your disk space on line with minimal impact on users. And you can do it blazingly fast. De-Frag/X is tied in with HP's Transaction Manager (XM) to ensure against loss of data.

De-Frag/X has a tier-based license fee ranging from $1,695 to $5,995. Annual support ranges from $540 to $850. LPS technical support is available from 7:30 a.m. to 5:30 p.m. weekdays. Faxes, e-mails and telephone messages received over the weekend or on holidays are answered the next business day. A technical support representative is available by beeper during non-business hours for emergencies. An evaluation copy is available upon request.

Disk Space Manager (DSM)
Bradmark
4265 San Felipe St. Suite 800
Houston, TX 77027
Tel: 800.294.1251
Fax: 713.621.1639
WWW: www.bradmark.com

A comprehensive disk space management utility for the HP 3000 (MPE/iX version 4.0 and later). You can rapidly list properties, populate, condense, defragment and spread your disk space. DSM operates online with minimal impact on users. And since it is tied to HP's Transaction Manager (XM), it can be interrupted at any time without losing work already done or corrupting data. You can choose to use DSM's built in disk space management algorithms for hands off management or use the individual commands in a hands on manner.

Disk Space Manager (Section 9.1 of DBGeneral) is available separately for a tier based license fee ranging from $2,000 to $15,000. Annual support is 20 percent of the current license fee. Bradmark technical support is available on a 24 x 7 basis. An evaluation copy is available upon request.

Review by John Burke

De-Frag/X from Lund Performance Solutions and Disk Space Manager from Bradmark are comprehensive disk space management utilities for the HP 3000. The two products are in many ways similar -- each does defragmentation, trimming, moving, spreading and combining. However, they are also very different. Each does things the other does not do, and each has its own distinguishing style. If you had unlimited funds, you could justify purchasing both based on the feature sets.

But there are more than feature sets to consider. The principal distinguishing characteristic is that each product is targeted at a somewhat different audience. Since few, if any of us, has an unlimited budget, I am going to describe some of the products' similarities and differences so that you can choose which one best meets your organization's style and needs. Ultimately, your best course of action may be to test drive both. But at least you will not be going in cold.

Background
Why is there a need for two third-party defragmentation/disk space management utilities? First, HP provides minimal, at best, support for disk space management. The CONTIGVOL command of VOLUTIL, added in the 5.0 release of MPE/iX, represents a meager effort to provide similar functionality to MPE/V's VINIT CONDENSE (See sidebar), no great shakes itself. Even at that, all it does is try to create enough contiguous disk space on LDEV 1 for an operating system update to succeed. Second, as 100-Gb plus disk farms become more common (consider that before the end of the year, you will be able to populate a single HASS enclosure about the size of a microwave oven with 72Gb) the need for tools to manage and tune these disk farms for maximum performance becomes ever greater.

Mismanaged disk space robs performance and hurts system availability in a variety of ways, some of which are:

• Insufficient contiguous disk space on LDEV 1 will prevent OS updates, or at the very least, make them a much more lengthy, complex and problematic process;

• Severe disk fragmentation could lead to unnecessary expenditures for additional drives;

• Severe disk fragmentation will prevent fork() from working in some situations, aborting processes such as Web servers;

• Severe file fragmentation will negatively impact serial I/O;

• Imbalanced volume sets will negatively impact all I/O;

• Imbalanced files will negatively impact random I/O (think IMAGE datasets); and

• Wasted disk space beyond file EOFs limits a valuable resource and could lead to expenditures for additional drives before really necessary.
  

De-Frag/X was written by Stan Sieler of Allegro Consultants who is probably known by almost everyone reading the NewsWire, if for no other reason than his high profile on HP 3000-L. Sieler also has seemingly had his hand in just about everything related to the HP 3000. For example, he is the author of the System Manager's and Developer's Toolboxes, also distributed by Lund Performance Solutions (See our Test Drive in the January, 1997 issue of the NewsWire).

Disk Space Manager was written by Paul Wang of SolutionSoft, less well known perhaps, but no less experienced. Paul was a principal architect of MPE/iX's Transaction Manager (XM) and is also the author of Compression Space Manager, distributed by his company, SolutionSoft, as well as ORBiT (See our CSM Test Drive in the June, 1996 issue of the NewsWire).

De-Frag/X is marketed as a stand-alone product. Disk Space Manager is packaged as Section 9.1 of Bradmark's DBGeneral but can be separately purchased. Both products run online (though better with less concurrent activity on the system), and both register all reads and writes through Transaction Manager (XM) to protect data integrity.

Figure 1 (DSM) and Figure 2 (De-Frag/X) show the commands available for each product and similar information displays for the same disk drive using product defaults. De-Frag/X displays information in terms of pages (4096 bytes), which can be confusing if you are not used to the terminology. By default, Disk Space Manager displays information in terms of the more familiar sectors, but you can change the unit of display to either Kb (1024 bytes) or pages.

Common features of both products:

• Trim unused, wasted space from files;
  
• Defragment drives or whole volume sets;
  
• Defragment (or combine) fragmented files to improve serial I/O;
  
• Create contiguous space on any drive;
  
• Balance the distribution of files on the multiple physical drives of a volume set;
  
• Balance the placement of extents across multiple physical drives to improve the I/O performance for files accessed predominantly in a random-access pattern;
  
• Utilize HP's Transaction Manager (XM) to ensure data integrity ; and
  
• Operate on-line while the system is in use without significantly degrading performance (though both products obviously work best and fastest on an otherwise idle system).

MEMMAP. This command produces a map of the specified disk drive, showing which pages are currently in memory.

FINDPAGE and FINDSECTOR. This command tries to find a file that contains a specified disk page or sector.

Unique Disk Space Manager Features
MANAGEFILE. This operates on filesets, placing and balancing extents to achieve better performance. It employs an intelligent algorithm to automatically truncate files, freeing otherwise wasted space, combine extents into one drive or spread extents over multiple drives, all with the goal of increased performance.

MANAGESET. This could be the only command you use. Actually, Bradmark includes a job file that you can use as is and which uses this command to automatically manage your system volume set. Run it periodically to maximize the effect. I streamed the job without difficulty on my crash-and-burn system, a 948 with about 8Gb of configured disk space (about 5Gb in use) and was able to see an obvious improvement in fragmentation and balancing. The job took about 50 minutes to complete, but of course time depends upon processor speed, disk farm size, number and complexity of files, speed of the drives, load on the I/O channels and other concurrent usage. MANAGESET takes a multi-step approach to managing disk space.

Documentation
The documentation for De-Frag/X, at a mere 17 pages, appears somewhat skimpy on first review. However, when you combine it with the online HELP, it turns out to be quite adequate. It provides something of a tutorial as you read through it -- definitely recommended as opposed to just using it as a reference. The documentation for DSM is integrated into the overall documentation for DBGeneral and is more robust. DSM also comes with a fascinating paper on disk-space management written, by DSM's author Paul Wang. I highly recommend reading it.

Installation
Both products take just minutes to install. Both use the HPSUSAN to manage licenses, so you will have to be alert to any changes that would affect the HPSUSAN of the licensed machine (such as a box swap upgrade).

Conclusion
The decision to purchase a disk space management utility ranks in importance with the decision about backup utilities. Fortunately, you can't go wrong with either Bradmark's Disk Space Manager or Lund's De-Frag/X. Each presents a robust solution to disk space management. De-Frag/X is targeted at the hands-on system administrator while Disk Space Manager is better suits the hands off administrator (actually, you can get your hands as dirty as you want). My recommendation? Unless you are certain of your preferred approach, or money is an overriding issue (the gap between DSM and De Frag/X is significant at the high end -- you are paying for the stand-alone management built into DSM), get an evaluation copy of each, and determine which best fits your facility and mode of administration.

Copyright 1997, The 3000 NewsWire. All rights reserved.