Datasheet

12 Chapter 1

Using Oracle ASM
PATH GROUP_# DISK_# MOUNT_S HEADER_STATU STATE TOTAL_MB FREE_MB
-------------- ------- ------ ------- ------------ ----- -------- ----------
/dev/raw/raw4 0 1 CLOSED FOREIGN NORMAL 39 0
/dev/raw/raw5 0 0 CLOSED FOREIGN NORMAL 39 0
/dev/raw/raw3 0 2 CLOSED FOREIGN NORMAL 39 0
/dev/raw/raw6 0 2 CLOSED CANIDATE NORMAL 2048 2048
ORCL:ASM01_004 1 3 CACHED MEMBER NORMAL 34212 30436
ORCL:ASM01_005 1 4 CACHED MEMBER NORMAL 34212 30408
ORCL:ASM01_006 1 5 CACHED MEMBER NORMAL 34212 30420
ORCL:ASM01_007 1 6 CACHED MEMBER NORMAL 34212 30297
ORCL:ASM01_008 1 7 CACHED MEMBER NORMAL 34212 30507
ORCL:ASM01_009 1 8 CACHED MEMBER NORMAL 34212 30404
ORCL:ASM01_010 1 9 CACHED MEMBER NORMAL 34212 30509
ORCL:ASM01_011 1 10 CACHED MEMBER NORMAL 34212 30449
ORCL:ASM01_012 1 11 CACHED MEMBER NORMAL 34212 30340
ORCL:ASM01_013 1 12 CACHED MEMBER NORMAL 34212 30357
In this view, you see that there are three disks that are not assigned to any group (those
with
GROUP_# set to 0). These are unassigned disks that ASM has discovered but that have
not been assigned to a disk group. Note the mount status of
CLOSED on those three disks,
which also indicates that the disk is not being accessed by ASM. The
HEADER_STATUS of
FOREIGN indicates that these disks contain data already and are owned by some process
other than ASM (in this case, these are voting disks for a RAC). If the
HEADER_STATUS says
CANIDATE, as with /dev/raw/raw6, then we could add this disk to an ASM disk group.
Notice that most of the disks have a
MOUNT_STATUS of CACHED and a HEADER_STATUS of
MEMBER. This means that the disk is currently part of an ASM disk group (which we will
discuss more in the next section).
There are some cases where the
V$ASM_DISK view will not report any disks. For example,
on our Windows XP system there are no raw disks to discover, so the
V$ASM_DISK view will
simply be blank. This is not a problem because we can use an existing file system as a loca-
tion for an ASM disk. We will discuss that in the next section as we show you how to add
disk groups to ASM.
Here are some things to be aware of with regard to ASM disk discovery:
ASM can discover no more than 10,000 disks. If you have more than that, ASM will

discover only the first 10,000 disks. This can occur when your ASM disk string is not
sufficiently restrictive and the directory that you are searching in has a number of raw
devices but many of them are not going to be assigned to ASM.
ASM will not discover any disk that contains an operating-system partition table.

ASM may discover disks that already contain Oracle data (as in our previous example

with the voting disks).
95134c01.indd 12 1/28/09 9:43:41 AM