Mohanad Awad wrote:Check this link http://jarneil.wordpress.com/2008/04/22/expanding-an-asm-disk/
My database use oracle ASM , I use storage for DATA (datafiles and archive ... ) . my storage around to be full , so i want to add new space to storage (new hard disks).
So my question ..... from DBA side is there anything must be done ? like fdisk new hard disk then added to disk group ? or the space will automatically added to total space ?
My storage admin told me that he can re-size the space from his side without doing anything from my side as DBA , is any problem for that way ? is new hard disk will be same as old one .
Please advice ,
Mohanad Awad wrote:Because the kernel driver ASMlib (with its command line script support) is optional.
can you advice me why oracleasm not found even that oracle install using oracle ASM !
------------------------------------------------------------------------------------------fdisk does not format. mkfs does. fdisk partitions.
DATA /dev/sdb3 DATA_0000 DATA_0000
* As you see above the disks it seem the disks not foramated with fdisk !! can you advice on this also ! /dev/sdb*
My storage admin told me that he can re-size the space from his side without doing anything from my side as DBA , is any problem for that way ? is new hard disk will be same as old one .NEVER do this unless you want to be restoring from backup. Have him give you a new device EXACTLY the same size as the current one. Then follow the docs on how to add a new disk for your environment.
Please advice ,
Mohanad Awad wrote:ASM creates a stripe set across disks in a diskgroup. So to have a balanced diskgroup, all disks in it need to be of the same size, and should be of the same speed. See support note +ASM Technical Best Practices For 10g and 11gR1 Release [ID 265633.1]+.
Why it must be same size if i use external redundancy ?
i mean of re-size from his side is to keep all current disk as it with same pa-rationing - and same size - , and he will add new hard disks and it will appear as new pa-ration oracle OS. so it's that fair ?I would not be comfortable with storage admins touching any of the LUNs I have in use in ASM. I would want hands off - and if extra space is needed, for them to assign brand new LUNs.
This what i mean for re-size , from storage side - storage admin - will add new disk to group on storage it self .... is this will effect on my current data ?If they touch existing LUNs that you are using as disks in an ASM diskgroup, they can trash your entire database.
Mohanad Awad wrote:If an ASM diskgroup contains 4 disks of 256MB each, and you want to add another 2 disks to the diskgroup - then those 2 new disks should also be 256MB in size each.
1 - New size of hard-desk (MUST) be same as exist one ! it's not clear for me , I use external redundancy , not NORMAL nor HIGH ! or it's the case not realted to redundancy / Mirror case ? so what the it must same size.
My current size of total ASM group is 500G so I must request new 500G ?It is not about the size of the diskgroup. It is about the sizes of the disks in the diskgroup. As these disks are striped (forget about mirroring as you are confusing that with striping). For a striped set of disks to be balanced, the disks in that striped set needs to be of the same size each.
2 - if ASMlib optional and dose not exist on my server and my disk look like this : /dev/sdb ....... and new one look like (/dev/sdc) ... so must i do anything must i use on OS ?No. But devices +/dev/sdb+ and +/dev/sdc+ seems like local devices? And you showed above these as partitions and partitions used as ASM disks?
or added directly from Oracle DB : alter diskgroup add disk '/dev/sdc' ; ........... ? JUST , my OS is Red Hat Enterprise Linux Server release 5.4 (Tikanga)Assuming this disk is the same size as existing disk(s) in that diskgroup, yes.
3- When and why we use ASMlib ?Management.
So there is tow Q :No it's not local device , it's come from storge , and my disk group contain just from one disk memeber ! from storge defination the group created from tow physical hard disk device ,