Use a Linux logical volume manager
A logical volume manager can help administrators in a number of circumstances, as this tip details. Do you have a tip from your experience? Follow this link to submit your tip and enter our tips contest.
A logical volume manager is an important tool for storage managers. With the 2.4 kernel release of Linux, the facilities for logical volume management have been considerably improved.
Logical volume managers are standard on Unix because they allow the kernel to maintain a logical view of the disks attached to the system rather than simply viewing them as separate disks or fixed size partitions. This is necessary for any kind of software RAID scheme that uses features such as mirroring and striping and it is very useful for storage administrators because it helps to virtualize the storage pool, making it easier to manage efficiently.
The basic logical volume management for Linux is contained in the Multiple Devices (MD) software RAID driver. This has been completely rewritten for the 2.4 kernel and its features and sophistication have grown significantly in the effort. It stresses efficient background reconstruction if there is a disk failure and getting high performance out of RAID implemented in software.
In addition to the Linux software RAID driver, which is built into Linux, there are other choices. The Linux Global File System (GFS), an alternative file system for Linux designed for large, complex installations, includes a volume manager, which manages storage as pools. Sistina Software Inc. (www.sistina.com) offers a product named Logical Volume manager with more sophisticated features.
A paper discussing volume managers in Linux is available on the Sistina web site.
Rick Cook has been writing about mass storage since the days when the term meant an 80K floppy disk. The computers he learned on used ferrite cores and magnetic drums. For the last twenty years he has been a freelance writer specializing in storage and other computer issues.
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Red Hat® Linux® Administrator's Handbook, 2nd Edition
Author : Mohammed J. Kabir
Publisher : Hungry Minds
Published : Feb 2001
This shop manual for installing, configuring and troubleshooting Red Hat Linux 7.0 is written for the experienced network administrator and is designed to provide "just in time" instructions for solving immediate, specific problems.