BCV copies can be used for backup, restore, decision support, and application testing., BCV devices contain no data after initial Symmetrix configuration. The full establish operation must be used the first time the standard devices are paired with their BCV devices.

1.  Associate the BCV Device for pairing:

To perform standard/BCV pairing, the standard and BCV mirror devices of your production images must be members of the same device group (Note:- Already discussed in previous post about creating device group and pairing devices). 


To associate BCV001 with device 0ABC,enter:

  symbcv –g DgName –sid SymmID associate dev 0ABC BCV001


Or to associate a range of devices to a device group, enter:


 symbcv –g DgName –sid SymmID associateall dev –RANGE 0ABC:0DEF


Note:- -sid SymmID is optional if you have already defined device group in symcli environment varaiable.


2. Unmount the BCV device:


Prior to using devices for BCV operations, the BCV device should be Windows formatted and assigned a drive letter.


If using basic disks on the Windows platform, you must unmount the BCV devices. If using dynamic disks, you must deport the entire TimeFinder device group.  For basic disks, use the syminq command to determine the SymDevName of the potential BCV device. For dynamic disks,use the TimeFinder  symntctl command to determine the volume and disk group name as follows:


symntctl list –volume [dg DgName]


Note that the term device group and dynamic disk group are the same applied to this command.


Unmount the selected BCV device as follows (with TimeFinder command):


symntctl unmount –drive z


Where z equals the designated drive letter.  If an error occurs, check for an “openhandle” and clear this condition.


For Veritas dynamic disks only, you must deport the disk group and rescan using the following commands:


vxdg deport –g DgName


symntctl rescan


3. Fully Establish BCV and STD:


To obtain a copy of the data on a standard device, the BCV device of the pair must be established.


To initiate a full establish on a specific standard/BCV device pair, target the standard device:


symmir –g DgName –full establish DEV001


Fully Establish all pairs in a group. To initiate a full establish on all BCV pairs in a device group, enter:


symmir –g DgName –full establish


Verify the completed (synchronized) establish operation. To verify when the BCV pairs reach the full copied or Synchronized state, use the verify action as follows:


symmir –g DgName –i 20 verify


With this interval and count, the message is displayed every 20 seconds until the pair is established.


Rescan the drive connections. For Dynamic disks only on a Windows host, you should rescan for drive connections visible to the host:


symntctl rescan


After any standard/BCV pair has been fully established and subsequently split, to save establish (resync) time, you can perform an establish operation omitting the -full option, which updates the BCV copy with only the changed tracks that occurred on the standard device during the elapsed BCV split time. To perform an incremental establish, omit the –full option, targeting the standard device
of the pair:


symmir -g DgName establish DEV001


Optionally, you can also collectively target all devices in a device group, composite group, or defined devices in a device file:


  symmir –g DgName establish [-full]


 symmir –g CgName establish [-full]


  symmir –file FileName establish [-full]


4. Prepare (freeze) Production database for a TimeFinder Split:


To prepare to split the synchronized BCV device from the production standard device, you must suspend I/O at the application layer or unmount the production standard prior to executing the split operation.


symioctl freeze –type DbType [object]


Ensure any residual cache on the Production host is fully flushed to disk. To insure all pending unwritten production file system entries are captured, enter TimeFinder command:


symntctl flush –drive z


Wait 30 to 60 seconds for the flush operation to complete.   


5. Split the BCV devices:


To split all the BCV devices from the standard devices in the production device group, enter:


symmir –g DgName split


To split a specific standard/BCV pair, target the logical device name in the group, enter:


symmir –g DgName split DEV001


6. Verify the split operation completes:


To verify when the BCV device is completely split from the standard, use the verify action as follows:


symmir –g DgName –i 20 verify –split -bg


With this interval and count, the message is displayed every 20 seconds until the pair is split.


7. Rescan for dynamic disks:


For dynamic disks only, you should rescan for drive connections visible to the host:


symntctl rescan


8. Mounting BCV device:


After splitting the BCV device, you can mount the device with captured data on another host and reassign the drive letter.


For basic disks, use the TimeFinder command:


symntctl  mount –drive z –dg DgName


For Dynamic disks, use the TimeFinder command:


 symntctl mount –drive z –vol VolName   –dg DgName | -guid VolGuid


For VERITAS dynamic disk only, you must deport the disk group and rescan, as follows:


vxdg deport –dg DgName


symntctl rescan


For Dynamic disk only (without Veritas), you can use the Microsoft diskpart command to select the disk and import the device using the online and import actions.


Note:- symntctl command available in TimeFinder/IM ( Integration Module).

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Sr. Solutions Architect; Expertise: - Cloud Design & Architect - Data Center Consolidation - DC/Storage Virtualization - Technology Refresh - Data Migration - SAN Refresh - Data Center Architecture More info:- diwakar@emcstorageinfo.com
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