[linux-lvm] Volume Group Size

Stuart Fox stuart at fotango.com
Wed Jun 25 13:28:02 UTC 2003


> On Wed, Jun 25, 2003 at 11:46:34AM -0600, Andreas Dilger wrote:
>> On Jun 25, 2003  18:00 +0100, Stuart Fox wrote:
>> > I cant find information about the maximum volume group size in the
>> current
>> > 2.4  series kernel.
>> >
>> > Id like to be able to join 2 1.75Tb raid arrays into  1 3.5Tb array.
>> > Is this possible?
>>
>> No, there is a limit of 2TB for all block devices in 2.4 kernels.  With
>> 2.5, there is a "large block device" configure option that lets you have
>> larger block devices.  There is apparently also a patch to support this
>> on 2.4 kernels, but AFAIK it is not very widely used/tested.
>
> The question was regarding volum goups, not logical volums.
>
> So, correct me if I'm wrong, but I think the answer is yes, you will be
> able to join 2 1.75 Tb volume groups into a single 3.5 Tb volum group,
> if only an apropriate extent-size was set on VG-creation.
>
> However, each Logical Volum in the Volum-Group need to be smaller than 2
> TB.
>
> AFAIK the "large block device" feature in 2.5 does not enable > 2TB
> logical volumes - it only fixes the general block-device layer, md and
> the scsi-subsystem. At least that used to be the case - maybe someone
> knows if it has changed?
>
>
> --
> Ragnar Kjørstad
> Zet.no
>

Thanks for the quick replies.
It actually applied to both one vg with one lv of 3.5Tb.
Guess I'll have to find another way.

Cheers

Stuart





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