[Figure] Mirroring Configuration

Replication Mode

Replication option employs both asynchronous and synchronous mirroring schemes. Understanding the advantages and disadvantages between synchronous and asynchronous mirroring is essential to the correct operation of this.

Async Mode

With asynchronous mirroring, each write is captured and a copy of this is made. That copy is queued to be transmitted to the target system as soon as the network will allow it. Meanwhile, the original write request is committed to the underlying storage device and control is immediately returned to the application that initiated the write. At any given time, there may be write transactions waiting in the queue to be sent to the target machine.  But it is important to understand that these writes reach the target volume in time order, so the integrity of the data on the target volume is always a valid snapshot of the source volume at some point in time.  Should the source system fail, it is possible that the target system did not receive all of the writes that were queued up, but the data that has made it to the target volume is valid and usable.

Sync Mode

With synchronous mirroring, each write is captured and transmitted to the target system to be written on the target volume at the same time that the write is committed to the underlying storage device on the source system.  Once both the local and target writes are complete, the write request is acknowledged as complete and control is returned to the application that initiated the write.  With synchronous mirroring, each write is intercepted and transmitted to the target system to be written on the target volume at the same time that the write is committed to the underlying storage device on the source system.  Once both the local and target writes are complete, the write request is acknowledged as complete and control is returned to the application that initiated the write.  

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

1. 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.
    
   [그림] 리소스 위자드 리소스추가 화면
    
2. Select 'MirrorDisk' from Resource Type lists and click 'Next' button. When add a resource from the mirror disk resource type name, this step will be skipped.
    
    [Figure] Select Resource Wizard View
   
   
3. Next steps are same as adding in resource type.
   

Adding in Resource Type

1. Resourcetype - Right Click - Add Resource.
   
     [Figure] Adding resource in a Resource type
   
   
2. Getting disk information.
    
   [Figure] Screen of Getting disk information.
   
   

3. Select the mirror volume and MCCS will renew the information.
   If you skip enter resource name, this will given 'Mirror_value' which value is selected driver letter.(Ex: Mirror_G)

   미러 디스크로 사용될 드라이브 문자는 양쪽 서버에서 같은 드라이브 문자로 되어있어야 합니다.
   [SAN 환경의 드라이브 문자(공유디스크)도 목록에 보여지므로 정확한 드라이브 문자를 선택하시기 바랍니다.]
   데이터는 소스로 지정  노드에서 타겟으로 지정된 노드로 복제됩니다.
   데이터가 존재하는 드라이브 문자를 선택하실 때 주의하시기 바랍니다.
   이미 만들어진 미러 볼륨을 추가 할 경우 볼륨레터 옆에 (mirrored)가 붙습니다.

       

   [그림] After gathering additional information screen

       

   [그림] 미러가 미리 구성되지 않은 볼륨 선택 시 화면

   

   [그림] 미러가 미리 구성되어 있는 볼륨 선택 시 화면  
                                                                         

4. 미러 디스크 리소스로 구성할 디스크가 없으면 다음과 같이 표시됩니다

   

   [그림] 미러 디스크 리소스 디스크 없음을 나타내는 화면

   
   

5. As 'Additional Settings', Synchronized Mode and Check Disk option is available.

   <동기화 모드>

   동기화 모드는 한 번 선택하면 변경할 수 없으므로 주의해서 선택해야 합니다.
   동기모드 : 응답속도는 느리지만 데이터 손실이 없습니다. 
   비동기모드 : 동기모드보다 응답속도는 상대적으로 빠르지만 데이터 손실이 발생할 수 있습니다.

   
   

   <디스크 검사 옵션>

   디스크 검사 명령 실행 옵션을 지정합니다. 자세한 기능은 MSDN을 참고하십시오.

   

   [Figure] Defining mirror type and check disk option

    

6. When click OK button, following popup message appear.
   Confirm selected server as source.
   If you select wrong sever, clock cancel button.
    
   [Figure] Alert popup message after click OK button
   
   
7. Click 'Finish'button and mirror disk resource is added.
    
   [Figure] Adding mirror disk resource is completed

Deleting

Select resource type - right click - delete resource

1. Select "Delete resource".
   
   [Figure] Delete mirror disk resource view
   
   
2. Click "Delete resource" and a confirming message about deleting resource will appear. 
   
   [Figure] check resource view
   
   
3. Click "OK" and a confirming message about deleting redundancy program of mirror configuration will 
   
   [Figure] Delete physical mirror disk view
   
   
4. Click "OK" and redundancy program is deleted. Click "Cancle" and only mirror disk is deleted. 

State

다음 테이블은 상태와 사용자 명령에 의해 발생되는 MCCS 리소스의 상태 이동에 대해 설명합니다.
명령은 사용자에 의해 발생되는 것을 전제로 합니다.
미러 디스크 에이전트: 미러 디스크를 관리하며, 복제 프로그램이 설치되어 있어야 합니다. 

Attribute

[Figure]  Mirror Disk Attribute Screen

속성 값은 해당 리소스를 등록할 때에 입력된 값이며, '리소스 고유 속성'에서 값을 변경하거나 확인할 수 있습니다.