Chapter 14. Configuring Data Storage
AT ITS MOST FUNDAMENTAL LEVEL, OUR JOB as system administrators is to serve up data, and to do so in just about any form our users demand. We are the Starbucks of the information age.
IBM recently celebrated the 25th anniversary of the IBM PC. The original PC model was capable of storing 128K of data on a 5-1/4 floppy and it could boot to a cassette tape. IBM then released the XT, which sported a massive 5MB hard disk drive that was as loud as a washing machine and cost about as much as an automobile.
Drive capacity has soared over the intervening years, and prices have plummeted. The server where I save my files has an array of 80GB drives that cost just over $200 apiece. Am I satisfied? No. The need for storage just grows and grows and grows.
Every time a professional takes on a new client, an engineering firm designs a new factory, a doctor scans a digital x-ray of a new patient, or an ad agency creates another multimedia presentation, another dollop of information goes into that huge maw that we call data storage.
A lot of data gets added. Not much goes away. Users treat the Delete key as if it were coated with contact explosive. They save and save and save until administrators simply refuse to store any more useless data and choke off the pipeline with quotas or by simply not buying more drives. Companies like EMC and Compaq and IBM vie in mythic battles to control just a portion of this huge market.
From a product perspective, data storage alternatives fall into these general categories (each embracing thousands of different offerings):
Fixed spinning storage.
This includes hard drives of any form on a bus that does not support simple removal such as IDE, ATA, and SCSI.
This includes hard drives on flexible buses such as Firewire, USB, and PCMCIA. It also includes solid-state storage.
This includes drives with disks that can be removed from the unit such as CD-ROM, CD-RW, DVD-ROM, DVD-RAM, Zip, JAZ, Orb, and MO along with floppies, superfloppies, ultrafloppies, and pretty-darned-near-a-hard-drive-but-still-classified-as-a-floppy floppies.
This includes just about any imaginable device where an engineer could figure a way to rub oxide-coated plastic against a magnetic head.
This chapter details the management of spinning storage with a focus on the operation of the Logical Disk Manager, or LDM. Microsoft licensed this technology from Veritas Software. LDM keeps track of the installed drives, their partitioning, and the required I/O methods. It also handles fault tolerance and data recovery.
Detachable and removable storage is managed by the Removable Storage Management service, or RSM. This service also handles tape storage units. For the most part, RSM has very little to do when managing spinning storage. It will get involved with CD jukeboxes and the like, but for day-to-day operation of removable spinning storage, you do not interface with RSM.
The topics covered in this chapter include:
Functional description of LDM
Disk changes made by LDM
Upgrading from NT4 or Windows 2000
Performing initial disk configurations
Creating partitions and volumes
Recovering failed fault tolerant disks
In addition, the 64-bit version of Windows Server 2003 and XP support a new disk management method on the Itanium platform called GUID Partition Tables, or GPTs. Chapter 2, "Performing Upgrades and Automated Installations," shows how to use the Extensible Firmware Interface (EFI) to set up storage on an Itanium machine. A section of this chapter is devoted to describing how to configure GPT-based storage after it has been initialized.
If you need more information about the hardware that underlies the storage subsystem, take a look at the Storage Review web site, www.storagereview.com. This site contains top-notch information about drives and storage alternatives along with excellent, independent technical reviews.
You may also want to pay a visit to www.storage.ibm.com/hdd/support/download.htm and download IBM's Drive Fitness Test utility. This is a quick way to test a wide range of features in your drives.