1. For every disk discovered, the first block is reviewed and the
ASMLIB label (ORCLDISK<DiskName>) is verified.
If found, then the block device<DiskName> is created under the
special directory /dev/oracleasm/disks.
During the disk discovery, ASMLIB uses file /proc/partitions.
2. If you are using EMC powerpath, you should explicitly set in
ORACLEASM_SCANORDER="emcpower" and ORACLEASM_SCANEXCLUDE="sd" in
/etc/sysconfig/oracleasm.
3. You can use blkid utility on Linux to determine which disk you used
for ASM, the result will tell you clearly which 2 disks are bind into
1 emcpower device, and which emcpower device you can used in ASM to
create diskgroups.
# blkid | grep asm
/dev/sdb1: LABEL="VOL1" TYPE="oracleasm"
/dev/sdd1: LABEL="VOL2" TYPE="oracleasm"
/dev/sde1: LABEL="VOL3" TYPE="oracleasm"
/dev/sdg1: LABEL="VOL4" TYPE="oracleasm"
/dev/sdo1: LABEL="VOL1" TYPE="oracleasm"
/dev/sdq1: LABEL="VOL2" TYPE="oracleasm"
/dev/sdr1: LABEL="VOL3" TYPE="oracleasm"
/dev/sdt1: LABEL="VOL4" TYPE="oracleasm"
/dev/emcpowerf1: LABEL="VOL4" TYPE="oracleasm"
/dev/emcpowerp1: LABEL="VOL3" TYPE="oracleasm"
/dev/emcpowero1: LABEL="VOL2" TYPE="oracleasm"
/dev/emcpowern1: LABEL="VOL1" TYPE="oracleasm"
4. You can use "oracleasm scandisks" in a live production environment,
typically it's safe.
5. There is no need to set "asm_diskstring" manually in most cases.
--
Kamus<kamusis@xxxxxxxxx>
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On Sat, Apr 9, 2011 at 2:47 PM, Radoulov, Dimitre<cichomitiko@xxxxxxxxx> wrote:
Hi Andrew,
thanks! I didn't know about kfod, I'll check it's output on Monday (kfod
disk=all -> path).
I don't have an access to the systems right now, but if I recall correctly,
v$asm_disk.path shows as ORCL:<disk_name>
(so most probably asm_diskstring is set to ORCL:* or similar, I'll check
that on Monday too).
Thank you!
Dimitre
On 08/04/2011 22:22, Andrew Kerber wrote:
I believe there are options with kfod to do some of this. The
asm_diskstring parameter should show you how it is finding the disks
currently. As I recall, if you try and change asm_diskstring, and current
disks arent listed it wont let you.
On Fri, Apr 8, 2011 at 4:04 AM, Radoulov, Dimitre<cichomitiko@xxxxxxxxx>
wrote:
One more question:
- oracleasm querydisk -p shows correctly all paths (physical and logical)
to the devices.
- oracleasm querydisk -d shows the first one found during discovery
How can we know which path was used originally, when the disk was created?
[...]
