[linux-lvm] lvcreate distributed extent option

[toby]

"ZECHA,HOLGER (HP-Germany,ex1)" wrote:
> 
> Hello,
> 
> what do you mean with
> > How about striping with the strip size equal to that of a logical extent?
> 
> Can you give an example for the lvcreate command.
> 
> The reason to do this is to distribute the disk I/O accross all disks. the
> logical extent 1 is on disk1, logical extent 2 on disk 2 and so on.
> This means during read of logical extent 1, the heade of the second disk can
> already be moved to prepare to read logical extent 2.
> 
> This allows us to do more I/O's per second
> 
> Holger
> 


Once you create a striped lv, you cannot extend it by adding more disks. Current
lvm version anyway.

I wanted mine to be more flexible, so I first made a software raid set then made
the pv on top of the raid. That was in Jan this year. Last week I doubled the
size by adding another software raid set. I expanded two of the ext3 formatted
lvs in the process.

Perhaps not the fastest system in terms of throughput, but quite convenient to
resize.


-tkb