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Re: Extend existing raw shared file system on Oracle RAC 10g

 
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Chui Kock You_1
Frequent Advisor

Extend existing raw shared file system on Oracle RAC 10g

Hi,

Do you have any idea on how to extend existing raw shared file system runing on Oracle RAC 10g? This file system is utilised by Oracle RAC database.

Hardware configuration.
Model:RX6600
Operating System:HPUX 11i version 2
Clustering:Oracle RAC Clustering no MCSG

Regards
Chui
7 REPLIES 7
Matti_Kurkela
Honored Contributor
Solution

Re: Extend existing raw shared file system on Oracle RAC 10g

Usually "raw" in a database context means "no filesystem".

If there is no MC/Serviceguard, it probably means there are no VGs either, and the database is accessing /dev/rdsk/cXtYdZ devices directly. Right?

In that case, rather than extending the existing LUNs, you should present new LUNs (ioscan -fnCdisk; insf), set their permissions to match the existing database LUNs (appropriate chown/chgrp/chmod commands), and then tell your DBA to extend the database onto them.

Are you using Oracle ASM to manage your raw LUNs?

MK
MK
Chui Kock You_1
Frequent Advisor

Re: Extend existing raw shared file system on Oracle RAC 10g

Hi Matti,

Usually "raw" in a database context means "no filesystem".

If there is no MC/Serviceguard, it probably means there are no VGs either, and the database is accessing /dev/rdsk/cXtYdZ devices directly. Right? "I think yes,but we are able to check the existing lvol,vg by using vgdisplay, lvdisplay"

In that case, rather than extending the existing LUNs, you should present new LUNs (ioscan -fnCdisk; insf), set their permissions to match the existing database LUNs (appropriate chown/chgrp/chmod commands), and then tell your DBA to extend the database onto them.

i) "Do we need to 'vgextend' the new disks into the existing Volume Group in nodeA and nodeB respectively?
If we already do 'vgextend' in nodeA for same disks, how about nodeB? Is it this configuration is done by Storage-EMC when assign the LUN."

ii) "Which part do we need to 'chown/chgrp/chmod ' commands, in ' /dev/rdsk/cXtYdZ '? If yes, what is the correct permissions? Just follow back the previuos permissions setting?"

Are you using Oracle ASM to manage your raw LUNs? " Will double check on this, and confirm the server didn't install MC/ServiceGuard"

Regards
Chui
Raj D.
Honored Contributor

Re: Extend existing raw shared file system on Oracle RAC 10g

Chui,

> ii) "Which part do we need to 'chown/chgrp/chmod ' commands, in ' /dev/rdsk/cXtYdZ '? If yes, what is the correct permissions?

- Once the devices/raw volumes are created, by default they will be root:sys ownership , however that may not work for the database user & group. (oracle/dba)

More precisely if you have oracle database and you are using raw device for this the ownership on the raw device file must be set correctly to match per the database user and group environment. So that the database can access them.

Ex: You have created LVM raw devices :
say:
/dev/vgora/r_CTL1 # 1024MB
/dev/vgora/r_CTL2 # 1024MB
..
..


The permission should be set after lvcreation , and it would look like below:

(example)
# I have created few raw lv with name r_CTL1 r_CTL2 ... r_CTLn .. (using lvcreate -n r_CTL1 ..)


# set the ownership to oracle:dba to the raw devices:

# cd /dev/vgora
# chown oracle:dba rr_*



# ls -lrt /dev/vgora/rr_*
...
crw-rw---- 1 oracle dba 64 0x050000 Jul 19 2009 rr_CTL1
crw-rw---- 1 oracle dba 64 0x051000 Jul 19 2009 rr_CTL2


[ The LV name willl be r_CTL1 , and raw lv name will be rr_CTL2 , and to see LV properties you can use :# lvdisplay /dev/vgora/r_CTL1
( where r_CTL1 is the naming convention kept here during creation of the raw device , with lvcreate. ]


brw-r----- This represents block device file, and crw-rw---- represents character device file/raw device used for oracle raw volumes.




If you are using VXVM:
The raw device path will be under:
/dev/vx/dg_name/rdsk/vol_name

And the ownership will be applicable same way like used in LVM , one can use chown or vxedit command to set the ownership.


Hth,
Raj.




" If u think u can , If u think u cannot , - You are always Right . "
Raj D.
Honored Contributor

Re: Extend existing raw shared file system on Oracle RAC 10g

correction:

[ The LV name willl be r_CTL1 , and raw lv name will be rr_CTL1 , and to see LV properties you can use :# lvdisplay /dev/vgora/r_CTL1 ]

Cheers,
Raj.
" If u think u can , If u think u cannot , - You are always Right . "
Chui Kock You_1
Frequent Advisor

Re: Extend existing raw shared file system on Oracle RAC 10g

Hi Raj,

Any update on the vgextend.

In that case, rather than extending the existing LUNs, you should present new LUNs (ioscan -fnCdisk; insf), set their permissions to match the existing database LUNs (appropriate chown/chgrp/chmod commands), and then tell your DBA to extend the database onto them.

i) "Do we need to 'vgextend' the new disks into the existing Volume Group in nodeA and nodeB respectively?

If we already do 'vgextend' in nodeA for same disks, how about nodeB? Is it this configuration is done by Storage-EMC when assign the LUN."

Regards
Chui
Suraj K Sankari
Honored Contributor

Re: Extend existing raw shared file system on Oracle RAC 10g

Hi,

To extend a RAW file system you just need to do one command which is

#lvextend -l 6000 /dev/vgxx/lvolx

no need to do vgextend.

Suraj
Raj D.
Honored Contributor

Re: Extend existing raw shared file system on Oracle RAC 10g

Chui,

With the original question :

> Do you have any idea on how to extend existing raw shared file system runing on Oracle RAC 10g? This file system is utilised by Oracle RAC database.

>> raw shared file system

- When it is raw , it cannot be a filesystem. A filesystem you can see with bdf/df command. And using fstyp -v /dev/vgxx/lvxx command.
- Raw devices you can see from the device directory, or you can ask the oracle team , they can tell easily from sql query.



Once you get the raw device names, find out which vg they are belongs to , check free space with vgdisplay. You can extend the raw devices using lvextend command.

Example:
- Suppose you have 1024MB current size, and want to add 1024MB to the raw device (/dev/vgora/rCTL1): use:

- # lvextend -L 2048M /dev/vgora/rCTL1

Thats it, Then you can verify with :
- # lvdisplay /dev/vgora/rCTL1 | grep "LV Size"

- vgexport/import not needed if you are just adding space. else it is required on the cluster node.

- You may provide more information about the raw devices details and other details further.,



Cheers,,
Raj.
" If u think u can , If u think u cannot , - You are always Right . "