Taking Backup of Datavg on running Aix System / FAST backup of datavg

How to clone data VG & restore to other system without downtime/fast clone. ( Well tested)

or 

How to take backup of running system if application availability is high  priority and offline backup takes near 5-8 hrs to get completed.

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Map the hdisky or lun to both the system

On system1:-

lspv

cfgmgr   ** to get new hdiskY/lun

Now Extendvg

extendvg vgname hdisky/lun

******if you are unable to extendvg due to Max pp limitation then change the Vg properties.

chvg -t 2|3|4 (etc)  vgname

extendvg vgname hdiskY

mirrorvg vgname hdiskY

lsvg -l vgname   * check all fs are syncd and consistent, else wait to get it consistent.

Freeze the Filesystems to keep the consistency and to clear the chace so that all data will be written on disk. 

chfs -a freeze=120  filesystem_names  ( all filesystem of that VG and application )

 This will freeze the filesystem no I/O will be happen. Users will get the application hanging issue for 2 mins but these 2 mins will be enough for you to split the consistent VG.

Now split the VG

splitvg -y new_vgname -c 2 -i old_vgname   ( -i is used so that hdiskY cant join the vg again and lv/fs remain consistent, else if you need the hdisk to rejoin the vg then dont use -i , -c 2 is to separate the second copy of lv i.e hdiskY)

Activate or thawn the filesystems:- Now activate the filesystems to be accessed by the application and Users.

chfs -a freeze= 0 filesystem_names  ( fielsystems whch were made frozen above)

Now you have only taken or say frozen the application for 2 -3 mins and you can take the backup of the consistent  datavg  as shown below:-

varyoffvg new_vgname

exportvg new_vgname

rmdev -Rdl hdiskY
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ON System 2 or TSM

Then map same hdiskY/lun to different system if you have not done earlier

lpsv

cfgmgr

lspv

importvg -y vgname( name you like to put) hdiskY

cp -p /etc/filesystems /etc/filesystems_copy

edit /etc/filesystems  remove unwanted prefix like /fs/fs etc
mount all

check VG doesn’t have any stale Lv.

Check files and application.

Remove mapping of hdisky/lun from system1.

Mount the filesystems

Take the backup on TSM for consistent datavg with the down time of 2-3 mins only on actual host and user will now keep on accessing the server or run the application as cloned server if your mksysb is also cloned on the target server.

That its.

Done!
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Extra using script to change lv or fs prefix if you want or else u can do it in /etc/filesystems file as I tested that also as stated above:-

the filesystems still have the "/fs/fs" prefix. So, a quick and dirty script cleans that up:

for fs in `lsvg -l datavg | grep fs | awk '{ print $7 }' | cut -d'/' -f 4-`       
do
chfs -m /$fs /fs/fs/$fs                                                             ****chfs -m newmount oldmount******
done

And, the LVs still have the "fs" prefix, I could leave them, but my OCD won't let me:

for fs in `lsvg -l datavg | grep fs | awk '{ print $1 }' | cut -d's' -f 2-`
do
chlv -n $fs fs$fs
done

Then I used "mount -a" to mount all the filesystems.