當DiskSafe建立policy之後，他會在/dev這個目錄底下建立一個名為disksafe的子目錄，裏頭記錄著有哪些disk/partition已經被DiskSafe所protect，我們可稱之為disksafe device
當DiskSafe建立policy之後，他會在/dev這個目錄底下建立一個名為disksafe的子目錄，裏頭記錄著有哪些disk/partition已經被DiskSafe所protect，我們可稱之為disksafe device，如:

# ls /dev/disksafe/
by-label  by-uuid  sda  sda1  sda2  sda3  sdb  sdc1  sdd1  sdd2

接著我們可以用dscli的指令查詢某個protection的狀態，如:

# dscli disk stat sda
Status and statistics for sda

	Primary Disk ID             	= sda
	Primary Device              	= /dev/sda
	DiskSafe Disk               	= /dev/disksafe/sda
	Primary DiskSafe ID         	= VMware__Virtual_disk____(0-0-0-0)
	Mount Point(s)              	= /boot:/:
	Primary Capacity            	= 10240.00 MB
	Group Name                  	=
	Mirror Device               	= /dev/sde
	Mirror DiskSafe ID          	= FALCON__IPSTOR_DISK_____6000d77a6ba99fee6eb600004e82e3f0
	Mirror Capacity             	= 10240.00 MB
Mirror Config:
	Protection Mode                              	= Continuous
	Initial Sync Time                            	= 2011/09/28 17:12:59
	Snapshot Scheduled                           	= True
	Schedule for Snapshot:
	Schedule Type                                	= Hourly
	Hours                                        	= 0
	Minutes                                      	= 30
	Start Date and Time                          	= 2011/09/28 17:09:03
	Limit I/O Throughput                         	= False
	Umap Path                                    	= /usr/local/falconstor/disksafe
	Umap DiskSafe ID                             	= VMware__Virtual_disk____(0-0-0-0)
	Maximum Snapshots                            	= 1000
	Take Temporary Snapshot Before Sync          	= False
	Invoke Snapshot Agent                        	= True
	Snapshot Agent Timeout                       	= 480 s
	Retry Period                                 	= 30 S
Mirror Status:
	Duration in Current State                    	= 410 S
	Different data                               	= 0 KB
	Total Data Mirrored                          	= 427136 KB
	Total Data Read                              	= 3001030 KB
	Total Data Written                           	= 6257273 KB
	Last Sync Start Time                         	= 2011/10/07 11:39:03
	Statistics Since Last Sync:
	Total Data Read                              	= 576 KB
	Total Data Written                           	= 5356 KB
	Status                                       	= IN-SYNC

Command succeeded

我們看到sda這個系統磁碟(mount point為/ 與 /boot)他的mirror是sde，protection mode為continuous，snapshot schedule為每30分鐘一次，他現在的狀態為IN-SYNC，代表primary與mirror是完全一致的sync狀態。

Policy的狀態有很多種，除了在continuous mode下的IN-SYNC，在periodic mode下的WAIT FOR NEXT SYNC也代表目前是sync的狀態。如果顯示SYNCING，就表示mirror正在sync；如果顯示OUT OF SYNC，則顯示primary與mirror並不同步。原因可能是I/O太多太急，或是網路太慢，導致sync失敗。

當OUT OF SYNC發生時，在continuous mode下，DiskSafe會持續的retry；在periodic mode下則會待到下次sync schedule的時刻再試著sync。在OUT OF SYNC的狀態下，snapshot是不會建立的。Snapshot必須是在資料完整sync時建立才有意義，否則將來從snapshot還原的資料也不會正確。

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