reduce a raw logical volume

[RK_7]

Dear all,

Can I reduce a raw logical volume without loosing data.

Regards

[Arunvijai_4]

RK,

You can use # lvreduce

-Arun

[RAC_1]

I do not know any fool-proof method for this.
I would do it in following way.

1 Back it up. (with backup softwares that can backup raw device)
2 Destroy and create with new size
3 Restore.

You can also do as follows.
Prepare temporary lvol.
copy the data to new lvol-dd
Remove and crreate new raw vol with require size and copy back with dd.

[RK_7]

Hi RAC,

If I do a dd How can I change my lvol size?

Regards

[Rajeev Shukla]

Is its a filesystem then you know how much you have used and you could reduce using lvreduce, but still a valid backup is required to be on safer side.
Now on a raw device, how do you know how much have you used? maybe you can tell if the raw device is used by say a database..but from system (OS) point of view you really dont know how much is used?
I therefore would go for a second method..
Backup the raw device, delete it and recreate of the required size.