Re: doubt about ASM

>I am thinking about a case where I am not able to open the database and
>decided to create a new database. So, there is no way to know through
>ASM which files are belong to which database. Suppose my database
>is down/corrputed/no controlfile .. and I need to check how much space
>this database was using.

ASMCMD can show you all this. Actually, ASM maintains sort of a file system and datafiles from certain database always go into corresponding virtual directory, like +DG/<DBNAME>/datafiles/<...>

So with ASMCMD you can simply

rm +DG/<DBNAME>

and all datafiles belonging to <DBNAME> will be deleted.

>It was showing these values from v$asm_diskgroup
> Total_mb = 1200 -- Understandable
> Free_mb = 1100 -- Understandable
> Required_mirr* = 300 ?
>
>
> Should it not to be shown 600mb in required* column
> since we should use only 50% space because we have
> created two failure group.

Worst failure this disk group can tolerate is loss of one failure group, which will reduce diskgroup capacity to 600mb. This means that at most 300mb of fully mirrored data could still be stored in this diskgroup after worst case failure, and at least 300mb of free space in remaining failgroup will be needed to restore data reduncancy. ASM knows that it can mirror on two disks within failgroup so that even if one disk in remaining failgroup dies the data will still survive. So the minimum amount of free space needed to keep data fully mirrored is 300mb - and maximum amount of data this diskgroup can store fully mirrored in the worst case scenario is also 300mb.

Hth,

    Vladimir M. Zakharychev
    N-Networks, makers of Dynamic PSP(tm)     http://www.dynamicpsp.com Received on Mon May 08 2006 - 08:31:32 CDT