How to resize ASM disks

Question

Hi! I have Oracle RAC on Centos with one active node and share storage HP MSA1500 12x500 Gb FC. Also, i have two servers which i want install new rac database.
[oracle@server ~]$ crsctl query css votedisk
0. 0 /u04/sync/oracrs/CSSFile
located 1 votedisk(s).
[oracle@server ~]$ ocrcheck
Status of Oracle Cluster Registry is as follows :
Version : 2
Total space (kbytes) : 262120
Used space (kbytes) : 1672
Available space (kbytes) : 260448
ID : 1521772939
Device/File Name : /u04/sync/oracrs/CRSFile
Device/File integrity check succeeded
Device/File not configured
Cluster registry integrity check succeeded
[oracle@server ~]$
CRS & CSS install on ocfs.
Затем, через oracleasm
[oracle@server ~]$ /etc/init.d/oracleasm listdisks
VOL8
VOL9
[oracle@server ~]$
[root@server ~]# /etc/init.d/oracleasm querydisk /dev/sda1
Disk "/dev/sda1" is not marked an ASM disk
[root@server ~]# /etc/init.d/oracleasm querydisk /dev/sdb1
Disk "/dev/sdb1" is marked an ASM disk with the label ""
[root@server ~]# /etc/init.d/oracleasm querydisk /dev/sdc1
Disk "/dev/sdc1" is marked an ASM disk with the label ""
[root@server ~]# /etc/init.d/oracleasm querydisk /dev/sdd1
Disk "/dev/sdd1" is marked an ASM disk with the label "VOL8"
[root@server ~]# /etc/init.d/oracleasm querydisk /dev/sdd2
Disk "/dev/sdd2" is marked an ASM disk with the label "VOL9"
[root@server ~]# /etc/init.d/oracleasm querydisk /dev/sdd3
Disk "/dev/sdd3" is not marked an ASM disk
[root@server ~]#
[root@server ~]# fdisk -l
Disk /dev/cciss/c0d0: 72.8 GB, 72833679360 bytes
255 heads, 32 sectors/track, 17433 cylinders
Units = cylinders of 8160 * 512 = 4177920 bytes
Device Boot Start End Blocks Id System
/dev/cciss/c0d0p1 * 1 50 203984 83 Linux
/dev/cciss/c0d0p2 51 1305 5120400 82 Linux swap
/dev/cciss/c0d0p3 1306 17433 65802240 83 Linux
Disk /dev/sda: 1048 MB, 1048657920 bytes
33 heads, 61 sectors/track, 1017 cylinders
Units = cylinders of 2013 * 512 = 1030656 bytes
Device Boot Start End Blocks Id System
/dev/sda1 1 1017 1023580 83 Linux
Disk /dev/sdb: 500.0 GB, 500071791104 bytes
255 heads, 63 sectors/track, 60796 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 60796 488343838+ 83 Linux
Disk /dev/sdc: 499.0 GB, 499025092608 bytes
255 heads, 63 sectors/track, 60669 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdc1 1 60669 487323711 83 Linux
Disk /dev/sdd: 500.0 GB, 500073750528 bytes
255 heads, 63 sectors/track, 60797 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdd1 1 1000 8032468+ 83 Linux
/dev/sdd2 1001 2000 8032500 83 Linux
/dev/sdd3 2001 3000 8032500 83 Linux
[root@server ~]#
Than in sqlplusi see, what disks use ASM:
SQL> select name, total_mb, free_mb,path from v$asm_disk;
NAME TOTAL_MB FREE_MB PATH
VOL1 476898 431798 /dev/raw/raw1
VOL2 475902 475379 /dev/raw/raw2
SQL> select name, total_mb, free_mb from v$asm_diskgroup;
NAME TOTAL_MB FREE_MB
DATA 476898 431798
RECOVERY_AREA 475902 475379
SQL> select name, type from V$asm_diskgroup;
NAME TYPE
DATA EXTERN
RECOVERY_AREA EXTERN
Also i see what disks use diskgroups DATA and RECOVERY:
[root@server ~]# cat /etc/sysconfig/rawdevices
# This file and interface are deprecated.
# Applications needing raw device access should open regular
# block devices with O_DIRECT.
# raw device bindings
# format: <rawdev> <major> <minor>
# <rawdev> <blockdev>
# example: /dev/raw/raw1 /dev/sda1
# /dev/raw/raw2 8 5
/dev/raw/raw1 /dev/sdb1
/dev/raw/raw2 /dev/sdc1
/dev/raw/raw8 /dev/sdd1
/dev/raw/raw9 /dev/sdd2
[root@server ~]#
[root@server ~]# mount
/dev/cciss/c0d0p3 on / type ext3 (rw)
none on /proc type proc (rw)
none on /sys type sysfs (rw)
none on /dev/pts type devpts (rw,gid=5,mode=620)
usbfs on /proc/bus/usb type usbfs (rw)
/dev/cciss/c0d0p1 on /boot type ext3 (rw)
none on /dev/shm type tmpfs (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)
configfs on /config type configfs (rw)
ocfs2_dlmfs on /dlm type ocfs2_dlmfs (rw)
/dev/sda1 on /u04/sync type ocfs2 (rw,_netdev,datavolume,nointr,heartbeat=local)
oracleasmfs on /dev/oracleasm type oracleasmfs (rw)
[root@server ~]#
[root@server ~]# ls -l /dev/oracleasm/disks/
total 0
brw-rw---- 1 oracle dba 8, 49 Aug 8 19:34 VOL8
brw-rw---- 1 oracle dba 8, 50 Aug 8 19:34 VOL9
[root@server ~]#
How i could resize asm disk from 450 G for example to 100 Gb for my new rac installation?
Sorry for my english:(

Answer 1

Hi mmusette, hi all,
please, allow a little clarification. ASM allows resizing disks:
From: http://download.oracle.com/docs/cd/B19306_01/server.102/b14231/storeman.htm#sthref1727
Resizing Disks in Disk Groups+
The RESIZE clause of ALTER DISKGROUP enables you to perform the following operations:
Resize all disks in the disk group
Resize specific disks
Resize all of the disks in a specified failure group
If you do not specify a new size in the SIZE clause then ASM uses the size of the disk as returned by the operating system. This could be a means of recovering disk space when you had previously restricted the size of the disk by specifying a size smaller than disk capacity.
The new size is written to the ASM disk header record and if the size of the disk is increasing, then the new space is immediately available for allocation. If the size is decreasing, rebalancing must relocate file extents beyond the new size limit to available space below the limit. If the rebalance operation can successfully relocate all extents, then the new size is made permanent, otherwise the rebalance fails.
However, if you have setup the ASM disk on a physical disk partition, you probably will not be able to resize the partition without destroying the data on the disk. If you, however, used a volume manager to create volumes and you based your ASM disks on those volumes (through RAW devices or directly) AND your volume manager allows resizing the volumes, you should be able to make use of the command mentioned above.
Thanks,
Markus