failgrp command

Purpose

Manages failure groups in a shared storage pool.

Syntax

failgrp -create [-clustername ClusterName] [-sp StoragePool] -fg FGName: PhysicalVolume ...

failgrp -create [-clustername ClusterName] [-sp StoragePool] -file -fg FGName: FileName

failgrp -remove [-clustername ClusterName] [-sp StoragePool] -fg FGName

failgrp -modify [-clustername ClusterName] [-sp StoragePool] [-fg FGName] -attr Attribute=Value

failgrp -list [-clustername ClusterName] [-sp StoragePool] [-verbose | -field FieldName ...] [-fmt delimiter [-header]]

Description

The failgrp command is used to manage the failure groups within a shared storage pool (SSP). A failure group is a set of physical volumes that are treated as a single point of failure by the system, which has one mirror copy of the data in a shared storage pool. By using the failgrp command, various operations, such as create, remove, modify, and list can be performed on the failure groups.

When a shared storage pool is created by using the cluster command with the -create flag, a default failure group is created. A new failure group can be created by using the failgrp command with the -create flag. This failure group is the second failure group and contains a mirror copy of the data in the default failure group. Ensure that the total capacity of the new failure group that you create is equal to or more than the total capacity of the default failure group.

Note: If the number of disks in the new failure group is more than the number of disks in the default failure group, an additional Physical Partition (PP) is needed per disk. The current size of a PP is 64 MB. For example, if a default failure group of size 1000 MB with 1 disk exists in the system, to create a second failure group with two disks, 1064 MB of space is needed.

Use -remove flag to remove failure groups from the shared storage pool. This means that one mirror copy of the data is removed. To display information about the failure groups in a shared storage pool, use the -list flag. Use the attr option with -modify flag to modify the specified attribute.

Note: Only two failure groups are supported in a shared storage pool.

Flags

Flag name	Description
-attr	Specifies the failure group attribute and a value to be changed. Supports the following attributes: `fg_name`
-clustername	Specifies the name of the cluster.
-create	Creates the failure group in a shared storage pool.
-fg	Specifies the name of the failure group. When this flag is combined with the -create flag, it specifies the physical volume names, which are separated by a white space or the file name, along with the failure group name.
-file	Specifies that a file name must be provided by using the -create flag. The file must contain physical volume names that are separated by a white space.
-field	Supports one or more of the following fields if the -list flag is specified: `fg_name, fg_size, fg_state, pool_name, tier_name`
-fmt	Separates output that is specific to an individual failure group, by a user-specified delimiter.
-header	Specifies the display field names in the formatted listing output.
-list	Lists failure groups in a shared storage pool.
-modify	Modifies the properties of a failure group.
-remove	Removes failure group from a shared storage pool.
-sp	Specifies name of the shared storage pool.
-verbose	Displays detailed information about the failure group.

Exit Status

This command returns the following exit values:

Return code	Description
0	Successful completion.
>0	An error occurred.

Examples

To create the myfg failure group within the mysp pool. in the mycluster cluster and on two disks hdisk1 and hdisk2, type the following command:
```
failgrp -create -clustername mycluster -sp mysp -fg myfg:hdisk1 hdisk2
```
The system displays the following message:
```
myfg failuregroup has been created successfully.
```
Alternatively, to create the myfg failure group by using the physical volumes from the pvfile file, type the following command:
```
failgrp -create -file -fg myfg:/tmp/pvfile
```
The pvfile file contents: hdisk51 hdisk52

The system displays the following message:
```
myfg failuregroup has been created successfully.
```
To modify the failure group name from myfg to newfg, type the following command:
```
failgrp -modify -fg myfg -attr fg_name=newfg
```
The system displays the following message:
```
Given attribute(s) modified successfully.
```
To list failure groups in a shared storage pool, type the following command:
```
failgrp -list
```
The system displays the following message:
```
POOL_NAME: sp
TIER_NAME: SYSTEM
FG_NAME        FG_SIZE(MB) FG_STATE
Default        20416       ONLINE
```
To remove the newfg failure group from the shared storage pool, type the following command:
```
failgrp -remove -fg newfg
```
The system displays the following message:
```
newfg failuregroup removed successfully.
```

Related Information

The chsp command, cluster command, and lssp command.