A shared disk agent is an agent that manages the shared disks.
Data on the shared disks will be damaged if you try to access to write from multiple nodes (or servers).
Thus, to control the situations, we only mount the file system from an operation node and unmount it to prohibit writing access from a standby node.
A shared disk agent manage mounting and unmounting of disks and monitors whether it is writable.

이 페이지의 주요 내용

Adding

There are two way to add a resource which one is select this from a group name and another is select this from a resource type.

Adding in Group

select a group → right click → 'Add Resource'.

[Figure] Adding Resource in a group
Select 'SharedDisk' from Resource Type lists and click 'Next' button.

[Figure] Select Resource Wizard View
Next steps are same as adding in resource type.

Adding in Resource Type

ResourceType → Right Click → Click Add Resource

[Figure] Adding Shared disk Resource in a resource type
Enter resource name, file system name, volume device file location and mount point.

[Figure] Shared disk resource information view
You can also browse the file name as click the file icon.

[FIgure] Click on file selection icon view
Click "Finish" when all of the values are entered.

[Figure] Finish Button Active after Entering All the Data
As Additional Settings, mount command option, forced to unmount option, filesystem check option is available.

[Figure] Additional setting view

Deleting

Select resource type →- right click → delete resource.

Select delete resource and resource will be deleted.

[Figure] Delete shared disk resource view

Status

The following table explains the status switching of the MCCS resource caused by a user's command and the status.
The command assumes that it is generated by a user.

Shared disk agent: Manages the shared disks registered in MCCS.

Status	Agent command	Decription
Online The volume is unlocked. You can write to it.	Offline	Dismounts the volume and prevents user from writing/reading data to and from the disk.
Online The volume is unlocked. You can write to it.	Monitoring	Checks if the volume is mounted and monitors if you can write to the volume by creating temporary files.
Offline The volume is locked. You can neither read or write from and to the volume.	Online	Mounts the volume and allow user to write/read data to and from the disk.
	Monitoring	Checks if the volume is mounted and monitors if you can write to the volume by creating temporary files.
Trouble The volume is online. But there is a problem caused by external elements. You cannot write to it. Access to the volume can be prohibited by the external commands or other driver, or the physical connections to the storage such as FC connections or SAN switches can cause troubles	Online	Mounts the volume and allow user to write/read data to and from the disk.
	Offline	Dismounts the volume and prevents user from writing/reading data to and from the disk.

Attribute

[Figure] Attribute of Shared Disk

Attribute	Description	Type	Default	Edit	Note
DevPath	Designate the path for the file of device to mount.	FILE		O
DoFsck	If it is set to true, going online will execute a fsck on the volume.	BOOLEAN	false	O
FileSystem	Enter the type of file system used by the volume.	STRING		O
ForceUnmount	If it is set to true, going offline will forcefully unmount the device in use.	BOOLEAN	false	O
FsckOpt	Enter the option used for fsck execution.	STRING	-a	O
MountOpt	Enter the command option used for mounting.	STRING		O
MountPoint	Enter the absolute path for the mounting location.	DIRECTORY		O

The attribute value is entered to register the resource, and you can change or check it in the 'Specified Attribute'.

7-5 Shared Disk