Guidelines for Selecting Slices for Mirrored File Systems

You can create a new boot environment that contains any combination of physical disk slices, Solaris Volume Manager volumes, or Veritas Volume Manager volumes. Critical file systems that are copied to the new boot environment can be of the following types:

• A physical slice.

• A single-slice concatenation that is included in a RAID-1 volume (mirror). The slice that contains the root (/) file system can be a RAID-1 volume.

• A single-slice concatenation that is included in a RAID-0 volume. The slice that contains the root (/) file system can be a RAID-0 volume.

When you create a new boot environment, the lucreate -m command recognizes the following three types of devices:

• A physical slice in the form of /dev/dsk/cwtxdysz

• A Solaris Volume Manager volume in the form of /dev/md/dsk/dnum

• A Veritas Volume Manager volume in the form of /dev/vx/dsk/volume_name. If VxVM volumes are configured on your current system, the lucreate command can create a new boot environment. When the data is copied to the new boot environment, the Veritas file system configuration is lost and a UFS file system is created on the new boot environment.

If you have problems upgrading with Veritas VxVM, see System Panics When Upgrading With Solaris Live Upgrade Running Veritas VxVm.

General Guidelines When Creating RAID-1 Volumes (Mirrored) File Systems

Use the following guidelines to check if a RAID-1 volume is busy, resyncing, or if volumes contain file systems that are in use by a Solaris Live Upgrade boot environment.

For volume naming shortcuts and guidelines, see RAID Volume Name Requirements and Guidelines for Custom JumpStart and Solaris Live Upgrade in Solaris 10 Installation Guide: Custom JumpStart and Advanced Installations.

Checking Status of Volumes

If a mirror or submirror needs maintenance or is busy, components cannot be detached. You should use the metastat command before creating a new boot environment and using the detach keyword. The metastat command checks if the mirror is in the process of resynchronization or if the mirror is in use. For information, see the man page metastat(1M).

Detaching Volumes and Resynchronizing Mirrors

If you use the detach keyword to detach a submirror, lucreate checks if a device is currently resyncing. If the device is resyncing, you cannot detach the submirror and you see an error message.

Resynchronization is the process of copying data from one submirror to another submirror after the following problems:

• Submirror failures.

• System crashes.

• A submirror has been taken offline and brought back online.

• The addition of a new submirror.

For more information about resynchronization, see RAID-1 Volume (Mirror) Resynchronization in Solaris Volume Manager Administration Guide.

Using Solaris Volume Manager Commands

Use the lucreate command rather than Solaris Volume Manager commands to manipulate volumes on inactive boot environments. The Solaris Volume Manager software has no knowledge of boot environments, whereas the lucreate command contains checks that prevent you from inadvertently destroying a boot environment. For example, lucreate prevents you from overwriting or deleting a Solaris Volume Manager volume.

However, if you have already used Solaris Volume Manager software to create complex Solaris Volume Manager concatenations, stripes, and mirrors, you must use Solaris Volume Manager software to manipulate them. Solaris Live Upgrade is aware of these components and supports their use. Before using Solaris Volume Manager commands that can create, modify, or destroy volume components, use the lustatus or lufslist commands. These commands can determine which Solaris Volume Manager volumes contain file systems that are in use by a Solaris Live Upgrade boot environment.