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Oracle10g R2 rawdisk in hpux11.31- restore as filesystem

Fauziah Mahdan
Super Advisor

Oracle10g R2 rawdisk in hpux11.31- restore as filesystem

HI,

I need opinion and advice from all.

I want to know what is the benefit creating database in raw disk?

From Server site I can't see where the file is, how much the usage and how much is the free space. We assigned space from SAN Storage around 1 tera for the database (raw disk and ASM).

I know our DBA can check from their tablespace usage but I want to know if there is anyway from server site

to check in details.

 

1 more question if I want to restore this raw disk db to DR and but as filesystem format, will it be possible?

How to perform this? BTW we are performing online full backup and incremental for archivelog using DP.

 

Thanks all.

 

8 REPLIES
Patrick Wallek
Honored Contributor

Re: Oracle10g R2 rawdisk in hpux11.31- restore as filesystem

No, there is nothing you can see from the server side when the DB is using raw disks.  You must rely on the DBA to manage and monitor the space appropriately.

 

No, I don't think you can restore the data from a raw disk as a  regular file.

klb
Valued Contributor

Re: Oracle10g R2 rawdisk in hpux11.31- restore as filesystem

 

Restoring from DP:  If you backed it up using a DP raw plugin, it'd be up to DP whether or not you can restore that archive to a regular file.  Maybe you could find a way to trick it though?

 

 

You can do this outside of DP though...

 

I've done both raw to raw and raw to cooked copies using dd like so...

 

# On the target host, do the following...

remsh <remote_host> -n 'dd if=raw_device_file bs=something_big |gzip -1' | gzip -d > local_file_or_raw_device

 

Couple things:

1) the gzip may slow things down if your boxes are on the same subnet or fairly close

2) setting the Oracle tablespace to BACKUP MODE or shutting down the DB prior to copy is required

3) the remsh will require that you've setup your .rhosts or hosts.equiv properly to allow access

 

Test it out with a small test database that's been configured on raw devices.

 

Oh, wait, you said ASM.  What a pitty, you're on your own then.  Maybe call up Oracle's vast support structure and wait for an ASM expert to tell you how to copy those devices over to a test area and get ASM running on them :( to duplicate your ASM databasef.

 

This is one good reason to NOT allow Oracle to do your I/O management!!!  There are many others, look it up, then go to your DBA and ask him/her what is the advantage.

 

 

Fauziah Mahdan
Super Advisor

Re: Oracle10g R2 rawdisk in hpux11.31- restore as filesystem

Tq all for the respond. I am looking at other way or atlast as you said have to ask my DBA how much space they require for db and ASM. I just allocate but again not sure where to assign means in term of vg and lvol because at prod it was assigned from SAN disk at DR from internal hard disk. Do I need to follow exactly the same for the vg and lvol no?

from bdf

Filesystem          kbytes    used   avail %used Mounted on
/dev/vg00/lvol3    5242880  320272 4884160    6% /
/dev/vg00/lvol1    1835008  354024 1469464   19% /stand
/dev/vg00/lvol11   8912896 1937512 6930072   22% /var
/dev/vg00/lvol10   4440064 3082056 1347456   70% /usr
/dev/vg04/lvol1    31440896 22006426 8844880   71% /u04
/dev/vg03/lvol1    19922944 11220262 8158815   58% /u03
/dev/vg00/lvol8    5242880 2291936 2767587   45% /u02
/dev/vg00/lvol7    15728640 12689852 2854676   82% /u01
/dev/vg00/lvol6    1048576  376936  667120   36% /tmp
/dev/vg00/lvol9    7389184 5532944 1841792   75% /opt
/dev/vg00/lvol5    1048576   52552  988280    5% /home
/dev/vg00/lvol4    5242880 3892215 1269189   75% /arch

Space from SAN as atatchment

Fauziah Mahdan
Super Advisor

Re: Oracle10g R2 rawdisk in hpux11.31- restore as filesystem

Ok from ASM I found this setting

DATA1 - 400GB

/dev/rdsk/disk24 -100GB

/dev/rdsk/disk27 - 100GB

/dev/rdk/disk33 - 100GB

/dev/rdsk/disk36 - 100GB

 

FRA - 400GB

/dev/rdsk/disk39 - 100GB

/dev/rdsk/disk42 - 100GB

/dev/rdsk/disk45 - 100GB

/dev/rdsk/disk48 - 100GB

 

My next question

At DR using internal disk I create above path but where to mount the filesystem?

Can I continue creating u05 and so on?

 

Next how to restore from DP from raw disk to filesystem and from RAC to non RAC?

 

Jean-Luc Oudart
Honored Contributor

Re: Oracle10g R2 rawdisk in hpux11.31- restore as filesystem

Hi

Once you use ASM you must use RMAN for your backup/restore functions.

The DBA should know all about it.

You can clone (duplicate) a database with RMAN.

RMAN can be integrated with your Backup tool.RMAN is part of the Oracle products but you will probably need to purchase an agent to integrate with your backup tool.

 

In a case of DR, the DBA will use RMAN to recover your database(s).

 

 

Rgds

Jean-Luc

 

fiat lux
Fauziah Mahdan
Super Advisor

Re: Oracle10g R2 rawdisk in hpux11.31- restore as filesystem

Ok yes I know I can restore using RMAN- DBA will perform that task, but before that I have to provide the space and location.

That part I am not clear. Reading from rawdisk /dev/rdsk/diskx

at DR I have /dev/vgxx/lvolx 

Then also not sure to set the mountpoint can I just prepare /u04 u05 and so on. 

 

 

Patrick Wallek
Honored Contributor

Re: Oracle10g R2 rawdisk in hpux11.31- restore as filesystem

I don't think you can restore from an ASM instance to a mounted filesystem.

 

When restoring at the DR site you ideally need to have the system there configured identically to your production system.  That way you will have far fewer problems restoring and will not have worries like this.

 

 

Jean-Luc Oudart
Honored Contributor

Re: Oracle10g R2 rawdisk in hpux11.31- restore as filesystem

Hi again

 

As your database runs on ASM storage, the underlying raw disks name don't really matter, as long as you have disk group to present to your database.

Once the structure is there you may have to add storage to an ASM disk group to allow for growth.

The database restore will be done by RMAN not raw disk restore as such.

 

I strongly recommend your run a test (and would probably start with a smaller database size to validate the restore to DR procedure).

If down time is an issue, have you (or more likely your DBA) thought of having a standby database.

 

And yes you can rename datafiles (ie relocate) but this needs to be scripted by your DBA.

 

Regards

Jean-Luc

fiat lux