7-5 Shared Disk
- 정은진
- 환기장
- 헌규임
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.
Table of Contents
Adding
Add the shared disk resource.
Before adding the shared disk resource, you must make sure that there exists an addable shared disk on the OS.
- select a group → right click → 'Add Resource'.
- Select 'SharedDisk' from Resource Type lists and click 'Next' button.
- Users must enter the file system type for shared disk, the file location of volume device for the both nodes, and information for the mounting position.
If the file location of volume device file is not known, the device file can be selected on a dialog by pressing the
'File' button.
[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 - Click the 'Finish' button to add the basic shared disk resource.
You can immediately check the result in the management web console.
Deleting
Select resource type →- right click → delete resource.
The deleted resource will immediately disappear from the management web console.
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 | Note |
|---|---|---|---|
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. | |
| 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. | 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
Shows the unique attribute of shared disk resource.
Attribute | Description | Type | Default | Edit | Note |
| ChkDskTimeout | 공유디스크 리소스가 디스크 검사를 완료하거나 중단되는 최종판단이 내려질 때까지 걸리는 최대 시간을 나타냅니다. 만약 '0'이라면 디스크 검사가 완료될때까지 기다립니다. | INTEGER | 0 | O | |
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'.