How to Expand an Existing Stripe (Command Line)

This procedure assumes that you are adding an additional stripe to an existing stripe. If you need to recreate a concatenated stripe using the metainit(1M) command as part of disaster recovery, refer to "How to Recreate a Stripe or Concatenation After Slice Failure (Command Line)".

A concatenated stripe enables you to expand an existing stripe. For example, if a stripe has run out of space, you can make it into a concatenated stripe, and expand it without having to back up and restore data.

If you use DiskSuite Tool to drag multiple slices into an existing striped metadevice, you are given the optional of making the slices into a concatenation or a stripe. When using the metattach(1M) command to add multiple slices to an existing striped metadevice, they must be added as a stripe.

After checking the prerequisites ("Prerequisites for Maintaining DiskSuite Objects"), and the preliminary information ("Preliminary Information for Expanding Slices and Metadevices"), use the metattach(1M) command to create the concatenated stripe. Refer to the metattach(1M) man page for more information.

Example -- Creating a Concatenated Stripe By Attaching a Single Slice

# metattach d2 c1t2d0s2
d2: components are attached

This example attaches a slice to an existing stripe, d2. The system verifies that the slice is attached.

Example -- Creating a Concatenated Stripe By Adding the Same Number of Slices in the Existing Metadevice

# metattach d25 c1t2d0s2 c1t2d1s2 c1t2d3s2
d25: components are attached

This example takes an existing three-way striped metadevice, d25, and concatenates another three-way stripe. Because no interlace value is given for the attached slices, they inherit the interlace value configured for d25. The system verifies that the Concat/Stripe object has been set up.

Depending on the type of application, by attaching the same number of slices, the metadevice might not experience a performance degradation.

Example -- Creating a Concatenated Stripe From Scratch

# metainit d1 3 2 c0t0d0s2 c1t0d0s2 -i 16k \
	2 c1t2d0s2 c1t2d1s0 -i 32k \
	2 c2t0d0s2 c2t0d1s2
d1: Concat/Stripe is setup

Normally, you would not create a metadevice such as this one from scratch. The example illustrates that d1 is a concatenation of three stripes (the first number 3). The first stripe consists of two slices (the number 2 following the number 3). The -i 16k specifies an interlace of 16 Kbytes. The second stripe (as indicated by the number 2 on the second line) consists of two slices, and uses an interlace of 32 Kbytes. The last stripe consists of a two slices. Because no interlace is specified for the third stripe, it inherits the value from the stripe before it, which in this case is 32 Kbytes.

Where To Go From Here

For a UFS, run the growfs(1M) command on the metadevice. Refer to "How to Grow a File System (Command Line)".

An application, such as a database, that uses the raw metadevice must have its own way of recognizing the metadevice, or of growing the added space.

To prepare a newly created concatenated stripe for a file system, refer to "How to Create a File System on a Metadevice (Command Line)".