Disk monitoring tools conserve capacity

EDS uses a number of disk monitoring and reporting tools as well as quota management software to manage Windows NT storage capacity.


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EDS, the world's largest provider of managed IT services, has found a way to keep Windows NT servers from running out of space by equipping its many on-site and in-house IT arsenals with tools to keep servers lean and clean.

Rick Fink, an EDS Windows NT systems administrator who manages servers at General Motors'

OnStar Division in Troy, MI, says employees have a voracious appetite for disk space. And there's good reason why they need space: The OnStar division provides an interactive emergency service for GM car owners. In case of an emergency, a driver can page OnStar, have a satellite pinpoint the car's exact location, and receive help immediately-all without the driver leaving the car.

However, graphics used in OnStar ads, engineering blueprints, and most of all, .wav files for the voice response part of the service, require a huge amount of storage. In late 1999, approximately 500 employees filled up one server's 35GB disk drive in less than nine months. If uncompressed, the data came to about 60GB.

Early this year, OnStar replaced most of the departmental Windows NT servers with a central, four-processor IBM NetFinity 5500 attached to three different RAID arrays. Approximately 500 on-site OnStar employees have home directories on this file and print server, which runs Windows 2000. Since the server is part of a Windows NT domain, about GM employees located at other sites also have access to this server.

Bursting at the seams

Within less than six months, the main production server almost burst at the seams. "On several occasions, we had just about run out of space. It didn't take long for word to get out that employees couldn't save anything," Fink explains. "The help desk got bombarded with telephone calls, and we had to tell employees to hurry up and remove files they didn't need."

To keep the server from running out of space, Fink put in a quota system to give each employee 64MB of space and increase this amount if specific employees had a reason for additional space. He selected W. Quinn Associates' StorageCeNTtral, which includes a quota management module called Quota-Advisor. StorageCeNTral also has other disk monitoring and reporting modules. Before loading it on the production server, Fink put the software through its paces on a test server for a month. He says, "We tried all sorts of things to make it crash, but it never did.

"StorageCeNTral enables you to set quotas on each employee's home directory, where you can track all of the files an employee owns on the server," Fink continues. "The quota management feature in Windows 2000 didn't suffice for us. It's aimed at the user level, making it difficult to get a look at all the files an employee has in his or her home directory."

Fink says the software integrates seamlessly with Windows Explorer. In fact, he easily set quotas on each home directory by going into Explorer, clicking on a specific directory, and selecting the QuotaAdvisor quota option.

The quota management module keeps a tally on how much space employees use toward their quotas. As employees get near their limit, the software sends them an on-screen, pop-up message asking them to either remove or delete files. If they exceed the quota, employees can save the documents they are working on but can't store any additional documents until they free up some space. "Overall, employees have been good about staying under their quota limit," says Fink. "If a supervisor requests additional space for an employee, we try to accommodate the request. We deal with an employee's request for space on a case-by-case basis."

Fink says DiskAdvisor, a real-time reporting module in the StorageCeNTral suite, lets him work proactively with employees so they don't have to call the help desk. The real-time reports that Fink frequently uses include

  • Disk usage by quotas to see if anyone is in any danger of tripping a quota;
  • Duplicate file report to see if the same files are stored in more than one area; and
  • Disk usage by directory to monitor directories such as shared areas that don't have quotas on them.

Of course, one of the problems of having employees store documents in a shared directory is that they often forget about them. However, "With the real-time reports, we know what directories to clean up," says Fink. If an employee contacts the help desk seeking more space for no apparent reason, Fink uses the reporting module to provide the employee with a list of his or her files. "We ask them to go through the list and delete or remove files. We won't provide any more space until they clean up their home directory."

Occasionally, Fink uses DiskAdvisor to do a random sweep of file types. "We found dozens of legitimate OnStar .wav files, but we deleted some of the .mp3s." If Fink needs to clamp down on certain file types, he can use FileScreen, another StorageCeNTral module, to set filters on certain file types and keep them from being stored on the server.

Meanwhile, when EDS's Specialty Insurance Services (SIS) unit in Bethesda, MD, put a space quota on two Compaq ProLiant Windows NT file and print servers, each of the 225 employees got 10MB of space. This division works with major insurance companies to adhere to regulations for processing flood-insurance claims. Ryan Cloyd, an EDS infrastructure analyst, says, "Since the insurance companies also access the servers, the quota system was necessary to control how space is being used on each server."

After six months, Cloyd says he had to adjust the space quota for many of the employees. He adds that some employees require as little as 5MB, while others need as much as 50MB to 1GB.

Like Fink, Cloyd uses StorageCeNTral to maintain the space quotas on the home directories and run reports if employees get an on-screen message saying they are about to reach their quota. He says, "Usually, we'll give some employees an extra 5MB and tell them they need to clean up their space by a certain time. We follow up with these employees a few hours after the deadline and reset the quota to its original limit. Employees are pretty good about cleaning up their space."

At EDS-SIS, two servers have become pack rats for some employees' collection of documents, including e-mail with file attachments. And freeing this stale space has become a delicate must-do for Cloyd. Since EDS-SIS deals with government regulations, employees have to keep specific documents for at least two years. "Some employees have five to eight years' worth of documents stored on these servers," says Cloyd. To help employees sort through these documents, Cloyd uses StorageCeNTral's DiskAdvisor feature to run reports showing the oldest files and those that haven't been accessed for the past year. Employees can use the reports to select the files they want to have burnt on a CD-ROM. He says, "The more space you have available on your servers, the better the performance."

Elizabeth Ferrarini is a freelance writer based in Arlington, MA.

Vendors of disk quota management tools

Astrum Software (www.astrumsoftware.com or www.storecast.com)
Northern Technologies (distributed by Argent Software-www.argent.com)
NTP Software (www.ntpsoftware.com)
W. Quinn Associates (www.wquinn.com)

This article was originally published on December 01, 2000