7-5 Shared Disk
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It is managed disk which multiple nodes share.
Within a cluster, the application may be store the data on shared disk when it is equipped.
MCCS manages the Unmount / Mount of the disk and monitors it is read/writable state. MCCS attach the shared disk to the only node to prevent file system corruption.
Table of Contents
Adding
Add the shared disk resource.
Before adding the shared disk resource, be make sure that the driver letter should be located in the external shared storage.
- When add a resource from a group name, select a group → right click → "Add Resource". Or select "Edit(E)" from the main menu bar → select "Add Resource". Or select "Add Resource" icon from the tool bar.
- Select "SharedDisk" from Resource Type lists and click the "Next" button. When add a resource from the shared disk resource type name, this step will be skipped.
Enter the resource name. Enter the file system type, volume device file location and mount point or click the
to browse these informations. Names of disks on both nodes which are used as resources of a shared disk have to be the same.
[Figure] Finish Button Active after Entering All the Data- As Additional Settings, mount command, forced to unmount and filesystem check options are available and click the "OK" button.
[Figure] Additional setting view - Click the "Finish" button to add the shared disk resource.
Deleting
Select "Resource type" →- right click → delete resource.
State
The following table explains the state of shared disk resource.
Shared disk agent: Manages shared disks registered for MCCS.
| State | Agent command | Decription | Note |
|---|---|---|---|
Online The volume is unlocked and is accessible. | Offline | It unmounts the shared disk. The disk cannot accessible from the node. | |
| Monitoring | It checks whether the volume is mounted and temp text file are created to monitor whether the disk is available. | ||
Offline The volume is locked and is not accessible to read/write. | Online | It mounts the shared disk. The disk can accessible from the node. | |
| Monitoring | It checks whether the volume is mounted and temp text file are created to monitor whether the disk is available. | ||
Fault The disk is unavailable due to errors caused by external factors or failure while it is online. | Online | It mounts the shared disk. The disk can accessible from the node. | |
| Offline | It unmounts the shared disk. The disk cannot accessible from the node. |
Attribute
Shows the specified attribute of shared disk resource.
Attribute | Description | Type | Default | Edit | Note |
| ChkDskTimeout | It is timeout limit to complete or stop the check disk of the shared disk before attaching it . If value is '0', MCCS waits to complete the check disk before attaching it. | INTEGER | 0 | O | |
DevPath | Defines absolute path of device that will be mount. | STRING | O | ||
DoFsck | If set to true, fsck will be performed when the shared disk is brought online. | BOOLEAN | false | O | |
FileSystem | Defines file system type of the shared disk. | STRING | O | ||
| ForceUnmount | If it is set to true, the shared disk will be forcefully unmounted when it is taken offline even tough it has been used. | BOOLEAN | false | O | |
| FsckOpt | Specify command option for file system check command | STRING | -a | O | |
| HostID | Unique server id for SCSI reservation | STRING | X | ||
| IOTest | Checks I/O status of a disk if it is set as true | BOOLEAN | true | O | |
| MountOpt | Defines mount options | STRING | O | ||
| MountPoint | Defines absolute path for the mounting location. | DIRECTORY | O | ||
| RegType | Register type of SCSI device | STRING | X | ||
| UseSCSILOCK | If it's set to true, Use SCSI reservation | BOOLEAN | false | O | |
| UUID | It's UUID of target disk. For example '00c0ffd79655000050042c4f01000000'. It will be set by automatically when you set proper letter. | STRING | X | ||
| VendorType | Vender type of SCSI device | STRING | X |
Specified attribute values are normally entered when add the resource, This value can be edited or viewed through 'Specified Attribute' table in the Resource Attributes tab on the detailed information panel.
MCCS has function to limit input values against user's input field, and it provides function detects automatically data which is input wrong by user's mistake.