Logical volume to raw device


 
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Operating Systems AIX Logical volume to raw device
# 1  
Old 05-08-2008
Logical volume to raw device

Hy
I have several logical volumes that are turned into raw devices used by Informix DB. I would like to add some more.

In /dev directory i see logical volumes as block files: lv_name1, lv_name2 ...

and

i see raw devices defined as character files:
rlv_name1, rlv_name2 ...

As i see, these LVs were turned into raw devices, somehow.

I found out the way to create new logical volumes using smit.
My question is, how to turn these logical volumes into raw devices?

Thanks!
# 2  
Old 05-08-2008
Quote:
Originally Posted by veccinho
[...]I found out the way to create new logical volumes using smit.
My question is, how to turn these logical volumes into raw devices?
[...]
Every LV is raw as long as you do not define any FS on it. The rest is just names...
# 3  
Old 05-08-2008
every logical volume that contains no filesystem is per definition a raw device ...
change the permission of the device to the database ownership (like on the already existent RAW devices) and initialise them from within the database ... thats it

Rgds
zx
# 4  
Old 05-09-2008
Quote:
Originally Posted by zxmaus
every logical volume that contains no filesystem is per definition a raw device ...
change the permission of the device to the database ownership (like on the already existent RAW devices) and initialise them from within the database ... thats it

Rgds
zx

Ok, great!
One more question.
When i create logical volume, it is by default created as block device.
But i see that all my raw devices assigned to the database are character-special devices.
Example, in my /dev directory i have following:
brw-rw---- 1 root system 10, 12 Dec 09 2005 lvinformix0

crw-rw---- 1 informix informix 10, 12 Mar 16 06:30 rlvinformix0

From a given example, only the rlvinformix0 device is assigned to the database.
So, how do i make this new LV to be a character device?
# 5  
Old 05-09-2008
every logical volume you are creating is appearing in /dev as a block- and a characterdevice

brw-rw---- 1 root system 10, 12 Dec 09 2005 lvinformix0
crw-rw---- 1 informix informix 10, 12 Mar 16 06:30 rlvinformix0

so assuming you have now created lvinformix1

you should see
brw-rw---- 1 root system 10, 12 May 09 06:40 lvinformix1
crw-rw---- 1 root system 10, 12 May 09 06:40 rlvinformix1

and all you need to do is chown informix:informix /dev/rlvinformix1

afterwards informix should be able to initialize this filesystem ...

Rgds
zx
# 6  
Old 05-13-2008
Quote:
Originally Posted by zxmaus
every logical volume you are creating is appearing in /dev as a block- and a characterdevice

brw-rw---- 1 root system 10, 12 Dec 09 2005 lvinformix0
crw-rw---- 1 informix informix 10, 12 Mar 16 06:30 rlvinformix0

so assuming you have now created lvinformix1

you should see
brw-rw---- 1 root system 10, 12 May 09 06:40 lvinformix1
crw-rw---- 1 root system 10, 12 May 09 06:40 rlvinformix1

and all you need to do is chown informix:informix /dev/rlvinformix1

afterwards informix should be able to initialize this filesystem ...

Rgds
zx
It worked just fine!
The only "problem" was that i didn't know that every new logical volume after its creation will appear as block- AND as character device.
Thanks for the info!
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