Snapping to VDEVs/Restoring to a SRC Using SYMCLI

 

Topic

Managing TimeFinder

Selections

Select TimeFinder Action: Managing TimeFinder with Solutions Enabler SYMCLI

Select operating system: Solaris

Select a task: Managing TimeFinder/Snap

Select a task: Snapping to VDEVs/restoring to a SRC

 

 

Contents

·             TimeFinder/Snap to VDEV and Restore to SRC.. 4

 


 

 

·        TimeFinder/Snap to VDEV and Restore to SRC    

 

Overview

In the following TimeFinder/Snap example, the data from a source device is copied to three different virtual devices. At different points in time, each virtual device is paired with the standard device and is the target of snap operation. A device group is used to control these three snap pairs.

After the last snap completes, data is restored to the standard device from one of the virtual devices.

This procedure is based on content from the following EMC manual:

·         EMC Solutions Enabler Symmetrix TimeFinder Family Product Guide

 

You can download the guide from EMC Online Support (registration required): https://support.EMC.com

 

 

1.   

Select VDEV devices

To list the devices on the Symmetrix array, enter:

 

   symdev –sid SymmID list –vdev

 

Select the VDEV devices to use for the snap operation.

 

 

2.   

Create the device group

Use the symdg command to create a device group. This example names the device group 3vdevs:

 

   symdg create 3vdevs –type regular

 

 

3.   

Add devices to the device group

Add the source and VDEV devices to the device group. In the following example the source device (76) is added, then the VDEV devices (4f, 50, 51) are added using the –range option, as follows:


    symld –g 3vdevs add dev 76

  symld –g 3vdevs addall dev –range 4f:51 –vdev

 

 

4.   

Verify the device group and status

To verify that the standard and VDEV devices are in the device group 3vdevs, enter:

 

 symld –g 3vdevs list

 

The status of the paired devices should be NotCreated.

 

Device Group (DG) Name: 3vdevs

DG's Type             : REGULAR

DG's Symmetrix ID     : 000000006206

 

        Standard Device Name           Directors              Device          

----------------------------------   ------------- ----------------------------

                                                                           Cap

Logical     Physical          Sym    SA :P DA :IT  Config        Att Sts   (MB)

----------------------------------   ------------- ----------------------------

 

DEV001      DRIVE29           0076   04A:0 16C:D2  2-Way Mir         RW    8632

Legend for STD devices:

 

(+): Paired with a BCV device that is associated with this dg.

(-): Paired with a BCV device that is non-associated with this dg.

 

Symmetrix Virtual Devices associated with this dg:

 

            VDEV Device                      Source Device           Status 

----------------------------------- ---------------------------- ------------Logical         Sym     Att.    Sts Logical         Sym          SRC <=> VDEV

----------------------------------- ---------------------------- -------------

 

VDEV001         004F            NR  N/A             N/A          NotCreated 

VDEV002         0050            NR  N/A             N/A          NotCreated 

VDEV003         0051            NR  N/A             N/A          NotCreated 

 

Legend for VDEV devices:

 

(+): VDEV is paired with a member device.

(-): VDEV is paired with a non-member device.

 

 

5.   

Create the snap pair session

The symsnap create command creates the snap pair session, sets up a track protection bitmap for each of the paired devices, and places the snap pair in the Created state.

 

   symsnap –g 3vdevs create –v DEV001 vdev ld VDEV001

 

 

6.   

Activate the snap pair session

The symsnap activate command places the snap pair in the CopyOnWrite (copy-on-first-write) state and the target virtual device in the Read/Write (RW) state. The actual copying of data is deferred until you modify tracks on either the source or the target.

 

   symsnap –g 3vdevs activate –v DEV001 vdev ld VDEV001

 

 

7.   

Confirm the snap pair session

The symsnap query command confirms that the first snap pair is in the copy-on-first-write state.

 

   symsnap –g 3vdevs query

 

8.   

Repeat steps 5, 6, and 7

Repeat steps 5, 6, and 7 for VDEV002 and VDEV003:

 

   symsnap –g 3vdevs create –v DEV001 vdev ld VDEV002

   symsnap –g 3vdevs activate –v DEV001 vdev ld VDEV002

   symsnap –g 3vdevs query

 

   symsnap –g 3vdevs create –v DEV001 vdev ld VDEV003

   symsnap –g 3vdevs activate –v DEV001 vdev ld VDEV003

   symsnap –g 3vdevs query

 

 

 

9.   

Verify copy sessions

Use the symsnap query command with the –multi option to display all three sessions:

 

   symsnap –g 3vdevs query –multi

 

Device Group (DG) Name: 3vdevs

DG's Type             : REGULAR

DG's Symmetrix ID     : 000000006206

 

      Source Device          Target Device                  State     Copy

------------------------- ------------------- ---------- ------------ ----

                Protected                        Changed

Logical   Sym   Tracks    Logical   Sym     G    Tracks  SRC <=> TGT  (%)

------------------------- ------------------- ---------- ------------ ----

 

DEV001    0076     276210 VDEV003   0051    X          0 CopyOnWrite    0

                   273902 VDEV002   0050    X       2308 CopyOnWrite    0

                   273603 VDEV001   004F    X       2607 CopyOnWrite    0

 

Total            --------                     ----------

  Track(s)         823715                           4915

  MB(s)           25741.0                          153.7

 

Legend:

(G): The Target device is associated with this group.

 

 

10.  

Restore to the source device

Note: Prior to performing a restore operation to the original source device, stop all activity on the file system by unmounting the file system.

 

Use the symsnap restore command to initiate an incremental restore operation that restores to DEV001 the original track data that was copied to a SAVE device during the copy session.

 

   symsnap –g 3vdevs restore DEV001 vdev ld VDEV003

 

Note: Once a restore operation is in progress (or complete), you can import the volume group and mount the file system.

 

 

11.  

Verify the restore operation

Use the symsnap query command with the –restore option to show the restore in progress:

   symsnap –g 3vdevs query -restore

 

 

12.  

Set the VDEV to Ready

When a restore operation is initiated, both the virtual device and the original source device (target of the restore) are set to Not Ready. Once the restore operation is underway, the source device is automatically set to Ready again. However, if you need to access the virtual device after the restore completes, you must use the symld ready command to set it to Ready again. The following command sets VDEV003 to Ready:

 

symld –g 3vdevs ready VDEV003 -vdev

 

 

13.  

Terminate the session

Once the restore operation is complete, you should terminate the restore session. The following command terminates the DEV001/VDEV003 restore session, but does not affect its copy session.

 

symsnap –g 3vdevs terminate -v DEV001 vdev ld VDEV003 -restored

 

 

7Table of Contents