HP OpenView Storage Data Protector HP OpenView Storage Data Protector A.05.
HP OpenView Storage Data Protector Table of contents Table of contents ....................................................................................... 2 Introduction .............................................................................................. 3 Setup details............................................................................................. 3 Method I – Instant Recovery reducing and extending......................................
HP OpenView Storage Data Protector Introduction This whitepaper describes the procedure for performing Instant Recovery in HP-UX LVM mirroring configuration using HP StorageWorks EVA and Data Protector. The reader is expected to read the whitepaper available for the extension of SMISA for HP StorageWorks EVA which enables you to perform ZDB (zero downtime backup) in an HP-UX LVM mirroring configuration before proceeding further.
HP OpenView Storage Data Protector Additionally the .omnirc variable set so that the replica is created on the second array. i. e. ZDB_LVM_PREFERRED_PVG=/dev/vg01:PVG-2 Note: Setting this variable is not a requirement for performing Instant Recovery in such setup.
HP OpenView Storage Data Protector PV Name PV Status Total PE Free PE Autoswitch /dev/dsk/c12t0d1 available 255 0 On --- Physical volume groups --PVG Name PVG1 PV Name /dev/dsk/c15t0d0 PV Name /dev/dsk/c15t0d1 PVG Name PV Name PV Name PVG2 /dev/dsk/c12t0d0 /dev/dsk/c12t0d1 # lvdisplay –v /dev/vg01/lvol1 --- Logical volumes --LV Name VG Name LV Permission LV Status Mirror copies Consistency Recovery Schedule LV Size (Mbytes) Current LE Allocated PE Stripes Stripe Size (Kbytes) Bad block Allocation IO Tim
HP OpenView Storage Data Protector Figure 2: Replica Created In this setup, when the backup is performed, the replica is created on the second array. Please see Figure-2 for the description. Instant Recovery can be performed using this replica by following the procedures mentioned below. To perform Instant Recovery on this setup following steps need to be performed.
HP OpenView Storage Data Protector Method I – Instant Recovery reducing and extending In this method, the mirrors are reduced to include only one volume, namely the physical volume group from which the backup was taken. After the volume is reduced, instant recovery can be performed cleanly. After the recovery is complete, the logical volume is mirrored again to include both physical volume groups.
HP OpenView Storage Data Protector Figure 3: Performing IR with reduced LVOL 1. Perform Instant Recovery. Instant recovery can be performed using the Data Protector GUI. For detailed instructions to perform instant recovery, please refer to the Data Protector ZDB Administration Guide. Note: If the “Check Data Configuration Consistency” is selected during Instant Recovery GUI, then Instant Recovery will not be successful in most of the cases, as the configuration of the volume group is changed.
HP OpenView Storage Data Protector the logical volume to contain two mirrors as in the original setup, following command can be used to extend the mirrors. lvextend -m 1 /dev/vg01/lvol1 /dev/dsk/c15t0d0 lvextend -m 1 /dev/vg01/lvol1 /dev/dsk/c15t0d1 This way, the logical volume lvol1 contains the disks /dev/dsk/c15t0d0 and lvol2 contains the disks /dev/dsk/c15t0d1 again as a mirrored copy.
HP OpenView Storage Data Protector 2 Used PV LV Name LV Status LV Size (Mbytes) Current LE Allocated PE Used PV /dev/vg01/lvol2 available/syncd 10240 256 256 2 LV Name LV Status LV Size (Mbytes) Current LE Allocated PE Used PV /dev/vg01/lvol1back available/syncd 10240 256 256 2 LV Name LV Status LV Size (Mbytes) Current LE Allocated PE Used PV .....
HP OpenView Storage Data Protector Schedule parallel LV Size (Mbytes) 10240 Current LE 256 Allocated PE 256 Stripes 0 Stripe Size (Kbytes) 0 Bad block on Allocation PVG-strict IO Timeout (Seconds) default --- Distribution of logical volume --PV Name LE on PV PE on PV /dev/dsk/c15t0d0 255 255 /dev/dsk/c15t0d1 1 1 --- Logical extents --LE PV1 00000 /dev/dsk/c15t0d0 00001 /dev/dsk/c15t0d0 ....
HP OpenView Storage Data Protector Figure 4: Splitting mirrors before performing the Instant Recovery 3. Perform Instant Recovery. Instant recovery can be performed using the Data Protector GUI. For detailed instructions to perform instant recovery, please refer to the Data Protector ZDB Administration Guide.
HP OpenView Storage Data Protector Figure 5: Performing Instant Recovery 4. Merge the mirrors. The mirrors are merged back to their original logical volume. In this process the newly created logical volumes (with the suffix ‘back’) would be merged back to their original logical volume. This way the mirror is created again to include both the volume groups.
HP OpenView Storage Data Protector Figure 6: Setup after performing lvmerge The command lvmerge is used to merge the mirrors. In the above example, if the logical volume lvol1 was splitted before performing the Instant Recovery. After performing the IR, following command can be used: lvmerge /dev/vg01/lvol1back /dev/vg01/lvol1 lvmerge /dev/vg01/lvol2back /dev/vg01/lvol2 With this command, the disks from logical volume lvol1 are merged back into the backup volume lvol1back, and the mirrors are recreated.
