Chapter 6 Managing the File System
Working With Stripe Groups
A stripe group contains definitions about read and write permissions, real time I/O constraints, a stripe breadth definition,
Stripe groups are bound together to create a StorNext file system. When data is written into the file system, two critical things happen.
First, data is separated from metadata. Metadata operations are typically small and random, and they require a lot of head movement on disks. Data however, tends to be written in large sequential patterns with less head movement. By separating data and metadata, thrashing is minimized and performance is maximized.
The second critical thing that can happen when data is written to the file system is file steering. Stripe groups can be different sizes and categories of disk, so you could have a file system with one stripe group of SATA disk intended for proxy files or temporary storage (i.e., less critical data on lower duty cycle, slower disk). You might have another larger fibre channel stripe group for storing raw content (i.e., high value data, on higher duty cycle, higher performance disk).
Getting data to specific stripe groups is accomplished using affinities, a mapping that ties a directory in the file system to a specific stripe group. When you write files to a directory, StorNext uses affinities to transparently write those files to the desired disk type. This means you don't have to have two or more separate file systems (e.g., one for critical data and another for temporary data). Instead, you have a single namespace for simplified management.
Working with a stripe group consists of these tasks:
• Adding a Stripe Group
• Modifying a Stripe Group
• Deleting a Stripe Group
| Use this procedure to add a stripe group. | |
Adding a Stripe Group | ||
1 From the SNFS home page, choose Stripe Groups from the Config | ||
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| menu. The Configure Stripe Groups screen appears. |
StorNext User’s Guide | 112 |
