openSolaris 2008 - Maintaining Disk Sets - Solaris Volume Manager Administration Guide

How to Check the Status of a Disk Set

Use one of the following methods to check the status of a disk set.
- From the Enhanced Storage tool within the Solaris Management Console, open the Disk Sets node. Click the right mouse button on the Disk Set you want to monitor. Then choose Properties from the menu. For more information, see the online help.
- Use the following form of the metaset command to view disk set status.
```
# metaset -s diskset-name
```
  See the metaset(1M) man page for more information.
  
  Note - Disk set ownership is only shown on the owning host.

Example 19-6 Checking the Status of a Specified Disk Set

The following example shows the metaset command with the -s option followed by the name of the disk set, blue. The output from this command displays status information for that disk set. The output indicates that host1 is the disk set owner. The metaset command also displays the disks in the disk set.

red# metaset -s blue


Set name = blue, Set number = 1

Host                Owner
  host1             Yes 

Drive               Dbase
  c1t6d0             Yes 
  c2t6d0             Yes

The metaset command by itself displays the status of all disk sets.

How to Delete Disks From a Disk Set

To delete a disk from a disk set, use one of the following methods:
- From the Enhanced Storage tool within the Solaris Management Console, open the Disk Sets node. Click the right mouse on the Disk Set that you want to release. Then choose Properties from the menu. Click the Disks tab. Follow the instructions in the online help.
- Use the following form of the metaset command to delete a disk from a disk set.
```
# metaset -s diskset-name -d disk-name
```
  -s diskset-name
  
  Specifies the name of a disk set on which to delete the disk.
  
  -d disk-name
  
  Specifies the disks to delete from the disk set. Disk names are in the form cxtxdx. The “sx” slice identifiers are not included when deleting a disk from a disk set.
  
  See the metaset(1M) man page for more information.
Verify that the disk has been deleted from the disk.
```
# metaset -s diskset-name
```
Note - To delete a disk set, you must first delete all the disks from the disk set.

Example 19-7 Deleting a Disk from a Disk Set

The following example shows the deletion of the disk, c1t6d0 from the disk set, blue.

host1# metaset -s blue -d c1t6d0
host1# metaset -s blue
 
Set name = blue, Set number = 1

Host                Owner
  host1            
    host2 

Drive               Dbase
  c2t6d0             Yes

How to Take a Disk Set

Note - This option is not available for multi-owner disk sets.

Use one of the following methods to take a disk set:
- From the Enhanced Storage tool within the Solaris Management Console, open the Disk Sets node. Click the right mouse on the disk set you want to take. Then, hen choose Take Ownership from the menu. For more information, see the online help.
- Use the following form of the metaset command.
```
# metaset -s diskset-name -t -f 
```
-s diskset-name

Specifies the name of a disk set to take.

-t

Specifies to take the disk set.

-f

Specifies to take the disk set forcibly.

See the metaset(1M) man page for more information.
Only one host at a time can own a disk set. When one host in a disk set takes the disk set, the other host in the disk set cannot access data on the disks in the disk set.
The default behavior of the metaset command is to allow your host to take the disk set only if a release is possible on the host that has ownership of the disk set. Use the -f option to forcibly take the disk set. This option takes the disk set whether or not another host currently has the set. Use this method when a host in the disk set is down or not communicating. If the other host had the disk set taken at this point, it would panic when it attempts to perform an I/O operation on the disk set.

Note - Disk set ownership is only shown on the owning host.

Example 19-8 Taking a Disk Set

In the following example, the host, host1, communicates with the host, host2. This communication ensures that the host host2 has released the disk set before the host, host1, attempts to take the disk set.

host1# metaset
...
Set name = blue, Set number = 1
 
Host                Owner
  host1
  host2
...
host1# metaset -s blue -t
host2# metaset
...
Set name = blue, Set number = 1
 
Host                Owner
  host1                Yes
  host2
...

If host2 owned the disk set, blue, the “Owner” column in the preceding output would still have been blank. The metaset command only shows whether the host issuing the command owns the disk set.

Example 19-9 Taking a Disk Set Forcibly

In the following example, the host that is taking the disk set does not communicate with the other host. Instead, the -f option allows the disks in the disk set to be forcibly taken without warning. If the other host had owned the disk set, that host would panic when it attempted an I/O operation on the disk set.

# metaset -s blue -t -f

How to Release a Disk Set

Releasing a disk set is useful when you perform maintenance on the physical disks in the disk set. When a disk set is released, it cannot be accessed by the host. If both hosts in a disk set release the set, neither host in the disk set can access directly the volumes or hot spare pools that are defined in the disk set . However, if both hosts release the disk set, the hosts can access the disks directly through their c*t*d* names.

Note - This option is not available for multi-owner disk sets.

Before You Begin

Check Guidelines for Working With Disk Sets.

Use one of the following methods to release a disk set:
- From the Enhanced Storage tool within the Solaris Management Console, open the Disk Sets node. Click the right mouse on the disk set that you want to release. Then choose Release Ownership from the menu. For more information, see the online help.
- To release ownership of the disk set, use the following form of the metaset command:
```
# metaset -s diskset-name -r
```
  -s diskset-name
  
  Specifies the name of a disk set on which the metaset command will work.
  
  -r
  
  Releases ownership of a disk set. The reservation of all the disks within the disk set is removed. The volumes within the disk set are no longer accessible.
  
  See the metaset(1M) man page for more information.
  
  Note - Disk set ownership is only shown on the owning host.
Verify that the disk set has been released on this host.
```
# metaset
```

Example 19-10 Releasing a Disk Set

The following example shows the release of the disk set, blue. Note that there is no owner of the disk set. Viewing status from the host host1 could be misleading. A host can only determine if it does or does not own a disk set. For example, if he host, host2, were to take ownership of the disk set, the ownership would not appear from the host, host1. Only the host, host2, would display that host2 has ownership of the disk set.

host1# metaset -s blue -r
host1# metaset -s blue
 
Set name = blue, Set number = 1

Host                Owner
  host1            
    host2

Drive               Dbase
  c1t6d0             Yes 
  c2t6d0             Yes

How to Delete a Host or Disk Set

Deleting a disk set requires that the disk set contains no disks and that no other hosts are attached to the disk set. Deleting the last host destroys the disk set.

Use one of the following methods to delete a host from a disk set, or to delete a disk set:
- From the Enhanced Storage tool within the Solaris Management Console, open the Disk Sets node. Click the right mouse on the disk set you want to release, then choose Delete from the menu. Follow the instructions in the online help.
- To delete the host use the following form of the metaset command.
```
metaset -s diskset-name -d -h hostname
```
  -s diskset-name
  
  Specifies the name of a disk set on which the metaset command will work.
  
  -d
  
  Deletes a host from a disk set.
  
  -h hostname
  
  Specifies the name of the host to delete.
  
  Use the same form of the preceding metaset command to delete a disk set. Deleting a disk set requires that the disk set contains no disks and that no other hosts own the disk set. Deleting the last host destroys the disk set.
  See the metaset(1M) man page for more information.
Verify that the host has been deleted from the disk set by using the metaset command. Note that only the current (owning) host is shown. Other hosts have been deleted.
```
# metaset -s disk-set
```

Example 19-11 Deleting a Host From a Disk Set

The following example shows the deletion of the host, host2 from the disk set, blue.

# metaset -s blue
Set name = blue, Set number = 1

Host                Owner
  host1            Yes 
..host2

Drive               Dbase
  c1t2d0             Yes 
  c1t3d0             Yes 
  c1t4d0             Yes 
  c1t5d0             Yes 
  c1t6d0             Yes 
  c2t1d0             Yes

# metaset -s blue -d -h host2

# metaset -s blue
Set name = blue, Set number = 1

Host                Owner
  host1            Yes 

Drive               Dbase
  c1t2d0             Yes 
  c1t3d0             Yes 
  c1t4d0             Yes 
  c1t5d0             Yes 
  c1t6d0             Yes 
  c2t1d0             Yes

Example 19-12 Deleting the Last Host from a Disk Set

The following example shows the deletion of the last host from the disk set, blue.

host1# metaset -s blue -d -h host1
host1# metaset -s blue
 
metaset: host: setname "blue": no such set