DB Backup on two different devclass?

[Bharanij]

hi guys,

i am taking db backup on devcalss file which is on e:\db\* as a admin schedule and set db recovery on same. now i want to take one more set of backup to tape which means i need two backup one to disk and other to tape is that possible ? if yes mean do i need to change or update set db recovery?

 

[RajeshR]

yes it's possible, just mention devc=tapedeviceclass on your backup db command, you don't need to change anything on set db recovery, if you wish to keep the default db backup to diskdeviceclass.
if you want db recovery to be tape device class then you have to update set db recovery to tape device class.
Note: During the start of the db backup to a different device class it will through a warning.

 

[Bharanij]

thank you for the reply

 

[marclant]

am taking db backup on devcalss file which is on e:\db\* as a admin schedule and set db recovery on same. now i want to take one more set of backup to tape which means i need two backup one to disk and other to tape is that possible ? if yes mean do i need to change or update set db recovery?

If you have a second Spectrum Protect Server in a different data center, you could do the following:

On Server1:
- backup the database to e:\db\*
- configure the baclient on Server1 to connect to Server2
- using the baclient, backup e:\db\* to server2

This doesn't give a copy to tape, but it gives you an offsite copy that is online. That's what many customers in disk-only environments do.


Those that don't have that option will typically do the following:
- backup db dev=disk type=full
- backup db dev=tape type=snapshot

The type=full purges the archive log. The type=snapshot doesn't purge the archive log. That's very important to know and to take into consideration.
- you would restore from disk in the event of data corruption and would be able to roll forward the logs because only the logs are managed by that backup
- you would restore from tape in a DR scenario because the server is destroyed

 

[RecoveryOne]

Those that don't have that option will typically do the following:
- backup db dev=disk type=full
- backup db dev=tape type=snapshot

I do exactly as marclant posts here.
My first database backup hits disk storage. Then I send a snapshot of the database to my offsite tape library. When the snapshot is completed, I have a define client action task set up for my NIM server to run a script to grab the devconf and volhist files as well so those are protected offsite.

 

[Bharanij]

Hi Guys,

thank you for the reply,

What iam doing right now is daily full backup on disk and keeping -5 backups five days before data will be clear as per expiry.

now i want to take full backup on tape as second copy dont want to delete that db. i dont want snapshot ( if i do dull backup do i need to take snapshot ?)

Note :-
1. i dont have second Spectrum Protect Server
2. i want db backup tape inside on LTO i dont take out side as offsite
3. can i take daily db backup on single tape ?

 

[RajeshR]

you can take DB full backup to tape by just mentioning tape device class name, you don't need to have a snapshot.
if ur db backup to disk dc running at 5 am, schedule another db full backup to tape at 5 pm (at your convenience)
you will require total 5 tapes, if you schedule one db full backup to tape everyday since your db backup retention is 5 days.

you can use only one stream to have db backup in single tape.

backup db devc=tapeclass type=full NUMStreams=1

if you mention numstreams on your backup db command it will over write any value that set in the db recovery.

 

[Bharanij]

thank you for the reply rajesh bro. but in our place we have limited tapes so i cant give 5 tapes for db backup.
what i am thinking will take backup on disk as usual and the make increment schedule to take that backups to tapes from disk. will that work? and backup db will not get corrupt when we take as file-system?

 

[RajeshR]

you cannot take incremental backup to tape when your full db backup is on disk device class.
And note, whenever you requested to take db backup whether its full or incr TSM will mount a scratch tape.
it cannot continue to write on existing tape.

unfortunately you cant use device class name to delete tape db backups from delete volhist commands, this will only works for virtual volumes.

So you need to have 5 tapes if you want 5 days tape backup whether its incr/full, Since db backup retention set for 5 days in your environment.

or you can run db backup to tape once in 2 days to reduce tape count through admin schedules.

 

[marclant]

2. i want db backup tape inside on LTO i dont take out side as offsite

What do you do if the building destroyed?

unfortunately you cant use device class name to delete tape db backups from delete volhist commands, this will only works for virtual volumes.

That's where doing a snapshot to tape and a full to disk is useful.
backup db type=full dev=disk
del volhist type=dbb todate=-2

backup db type=snapshot dev=tape
del volhist type=dbs todate=-5

now i want to take full backup on tape as second copy dont want to delete that db. i dont want snapshot

What's the reason for not wanting a snapshot? It gives you a recovery point. You can't rollforward, but you already have your database backup on disk which is much quicker to restore. Since you have a backup on disk, the only use I see for tape is for disaster recovery in case the server, room or building is destroyed. And the tape is currently not even useful for that since you keep it onsite. Unless you plan to start shipping your tapes offsite, there's really no value in doing a backup db to tape.


EDITED to remove incorrect statement about using devclass with delvolhist.

 

[RajeshR]

Actually, I checked the syntax and you can specify a devclass:

Yes i do agree you can specify but it will only work for virtual volumes server-server.

tsm: >DELETE VOLHISTORY t=dbs devc=LTOCLASS todate=today-30
ANR6978E DELETE VOLHISTORY: Invalid device class LTOCLASS
ANS8001I Return code 3.

tsm:>q devc LTOCLASS

Device Device Storag- Device Format Est/Max Mount
Class Access e Pool Type Capacit- Limit
Name Strategy Count y (MB)
--------- ---------- ------- --------- ------ -------- ------
LTOCLASS Sequential 1 LTO ULTRI- DRIVES
UM6C

 

[marclant]

Yes i do agree you can specify but it will only work for virtual volumes server-server.

Thanks for the clarification. Then this makes a case for using backup to disk and snapshot to tape.