Snap Copy Procedures for a Database:  Point-in-TimeSnap Copy for Off-host Backup RecoveryOperations

Description:  These procedures demonstrates howVeritas vxsnap commands (FastResynch license required) may be used to obtainpoint-in-time snap copy of database data structure volumes for off-host backup.This involves using a second equivalent volume(s) --known as the snap volume--to obtain a fully synchronized point-in-time copy of a database can be quiesced(write I/O suspend) briefly followed by snap volume disk group deport-import(Disk Group Split-Join license required) for off-host tape backupoperation.  This example operation assumes the database can be "suspended"and "resumed" and is using file containers (rather than raw devices) fordatabase storage structures under the management of Veritas-Veritas VolumeManager and VxFS. Also simulated is the vxsnap command operation for databasestructures recovery from off-host restoration from backup.

Prepare forDatabase Point-in-time Snap Copy Operation----
1.  Create a databasevolume (note specific disk/LUNs used for primary volume)
HostA: #vxassist  -g dg_db4prod make vol_db4prod1 20g layout=stripe stripeunit=128ncolumn=4 alloc=t21lun0,t21lun1,t31lun0,t31lun1
HostA: #vxprint -htgdg_db4prod

2.  Add DCO (data change object) logging to the databasevolume  (note disk/LUNs allocated)
HostA: # vxsnap -gdg_db4prod  prepare vol_dbprod1 regionsize=64kalloc=t21lun0,t21lun1,t31lun0,t31lun1
HostA: #vxprint -htgdg_db4prod

3.  Create a mirror (or plex) of the databasevolume  (note specific disk/LUNs allocated for snap volume)
HostA: #vxsnap -b -g dg_db4prod addmirvol_db4prod1  alloc=t41lun0,t41lun1,t42lun2,t42lun3
[SF 5.0:  #vxsnap -b -g dg_db4prod mirrorvol_db4prod1  alloc=t41lun0,t41lun1,t42lun2,t42lun3 ]
--monitor forcompletion:  synchronization task
HostA: # vxtask -l list
HostA:#vxprint -htg dg_db4prod


Cyclic Database Point-in-time Snap Copyfor Off Host Tape Backup Operation----

4.  Create the snapvolume with its DCO (note the targeted plex follows new snap volume)
Host A:# vxsnap -g dg_db4prod makesource=vol_db4prod1/newvol=snapvol_db4prod1/plex=vol_db4prod1-02
HostA:#vxprint -ht

5.  Snap copy pre-synchronization
HostA:#  vxsnap -b -g dg_db4prod refreshsnapvol_db4prod1  source=vol_db4prod1  
--monitor forcompletion:  synchronization task
HostA:  #vxtask -llist
(Note: If substantial time has passed since step 4, you may need torepeat this command to reduce the synchronization for the limited databasequiesce time)


6.  Make Database Quiescent:  suspend writeIO


7.  Snap copy point-in-time synchronization (synchronizevolumes during database suspend)  
HostA: # vxsnap -b -g dg_db4prodrefresh snapvol_db4prod1 source=vol_db4prod1
--monitor forcompletion:  synchronization task
HostA:# vxtask -llist

8.  Cause the database to resume:  resume writeIO


9.  Split off the snap volume with its own diskgroup for deport to the backup host
HostA: #vxdg list
HostA: # vxdg splitdg_db4prod dgSnap4prod snapvol_db4prod1
HostA: #vxdglist

10.  Deport the snap disk group from the databasehost
HostA: # vxdg deport dg_Snap4prod
HostA: #vxdisk -o alldgslist

11.  Import the disk group into the backup host
HostC: #vxdg import dg_Snap4prod
HostC: #vxdisk -o alldgslist


12.  Restart volumes after the import
HostC: #vxprint-htg dg_Snap4pord
HostC: # vxrecover -s -g dg_Snap4prod
HostC: #vxprint-htg dg_Snap4pord


13.  Mount read-only the file system of thevolume
HostC: # mount -r -F vxfs -o ro,largefiles,suid/dev/vx/dsk/dg_Snap4prod/snapvol_db4prod1 /db4prod1

14.  IssueBackup Operation to copy file system /db4prod1 to tape
Forexample:
Netbackup Master:  /usr/openv/netbackup/bin/bpbackup -i -cdomainc_dbpbib01_snap

15.  Monitor tape backup operation forcompletion


----Return thevolume to the database server host ----

16.  Unmount the filesystem  

(Normally "-f" is not recommended; in this case it is nota problem for read-only file system)
HostC:  # umount-f  /db4prod1

17.  Deport the snap disk group from the backuphost
HostC: #vxdg list
HostC: # vxdg deport dg_Snap4prod
HostC: #vxdglist

18.  Import the snap disk group into the database serverhost
HostA: # vxdisk -o alldgs list
HostA: # vxdg importdg_Snap4prod

19.  Merge imported disk group into the production diskgroup.
HostA: # vxdg join dg_Snap4prod dg_db4prod
HostA: # vxprint -htgdg_db4prod

20.  Restart the snap volume after disk group import
HostA: # vxprint -htg dg_db4prod
HostA: # vxrecover -s -gdg_db4prod
HostA: # vxprint -htg dg_db4prod

21.  Re-attach thesnap volume as an additional plex to the primary volume
HostA: # vxsnap -gdg_db4prod reattach snapvol_db4prod1 source=vol_db4prod1  
--monitor forcompletion:  synchronization task
HostA: # vxprint -htgdg_db4prod
#vxprint -g -F%incomplete
(SF5.0 nowsupports   #vxsnap -g snapwait as follow-oncommand)

22.  To begin a future Snap Copy Backup Operation return tostep 4 above.






Database Recovery:  Restorefrom backup tape or current snap volume----

a.  Netbackuprestore from tape :  /db4prod1   file system

d.  Unmountthe file system
HostC:  # umount -f /db4prod1

b.  Deport thesnap disk group from the backup host
HostC: # vxdgdeport  dg_Snap4prod

c.  Import the snap disk group into thedatabase server host
HostC: # vxdg import dg_Snap4prod

d.  Mergethe snap disk group with the primary disk group
HostA: # vxdg joindg_Snap4prod dg_db4prod

e.  Restart the snap volumes
HostA: #vxrecover -s -g dg_db4prod

f.  Stop the database for restore andrecovery


g.  Unmount thedatabase file system  
HostA: #umount  /db4prod1      
(Caution: you might use "-f";make sure users or applications are not writing to the filesystem)

h.  Synchronize from snap copy volume to the primarydatabase volume
HostA:#  vxsnap -g dg_db4prod restore vol_db4prod1source=snapvol_db4prod1 syncing=yes
--monitor forcompletion:  synchronization task
HostA: # vxtask -llist

j.  Mount the database file system
HostA: # mount -F vxfs -orw,largefiles,suid /dev/vx/dsk/dg_db4prod/vol_db4prod1 /db4prod1

k. Startdatabase with appropriate database log  "rollforward"



Created by Wes Ramirez,  09July07