[linux-lvm] LVM2 with disks greater than 2TB

Tue Mar 28 22:20:27 UTC 2006

Yeah I thought it would care about the partition label so I made a bad 
assumption it had to be lvm when it doesn't at all.  It worked fine with 
reiserfs and now I have my 9.09TB partition.  Thanks everyone for the help.

Devon H. O'Dell wrote:
> 2006/3/28, Barnaby Claydon <bclaydon at volved.com>:
>   
>> Dan, you should still be able to use LVM. The pvcreate create command
>> should still work on each of the two 4.6TB partitions and then use those
>> two PVs in your LVM.
>>
>> How far did you get after using Parted and GPT ? Did you get LVM-related
>> errors that I may not be considering? :)
>>
>> -Barnaby
>>     
>
> I had this problem earlier. The issue ended up being the same: I
> forgot to create GPT labels for the partitions. I had 2x4TB arrays I
> needed to span into a single 8TB array for several systems. The steps
> I use when making these LVM partition are as follows:
>
> parted /dev/sdb
> mklabel gpt
> mkpart
> primary
> xfs
> 0
> 4196049
> select /dev/sdc
> mklabel gpt
> mkpart
> primary
> xfs
> 0
> 4196049
> quit
>
> At the shell, type:
>
> pvcreate --metadatasize 1M /dev/sd{b,c}1
> vgcreate -s 128M vg0 /dev/sd[bc]1
> lvcreate -n lv0 -L8T vg0
> mkfs.xfs /dev/vg0/lv0
>
> The sizes are arbitrary numbers that I got while playing around with
> them and are the first ones that actually worked without whining at me
> about metadata sizes when creating the logical volume. Dan, LVM
> doesn't really care about the partition label. You should be able to
> do what I did above (but then with ReiserFS) to get what you need.
>
> With standard DOS partitions this will not work, as they only support
> 2^32-1 bytes.
>
> --Devon
>
>   
>> Dan wrote:
>>     
>>> It was indeed a partition problem.  Thanks.  fdisk does not support
>>> partitions over 2TB so I had to use GNU Parted to setup the partition
>>> with a GPT label that supports over 2TB.  I could then create reiserfs
>>> filesystems and got two 4.6TB partitions.  Unfortunately Parted and
>>> GPT do not support LVM so I could not raid the two partitions into one
>>> giant one unless I am missing something.  But the 2 partitions will
>>> work fine for what I need.  For anyone who might be interested I found
>>> the info I needed at the links below:
>>> http://www.coraid.com/support/linux/contrib/chernow/gpt.html
>>> http://www.gnu.org/software/parted/manual/html_chapter/
>>> http://www.wlug.org.nz/GPT
>>>
>>> Judd Tracy wrote:
>>>       
>>>> I recall having a similar problem when I setup a large array a long
>>>> time ago and it was related to the partition table if I remember
>>>> correctly.  I wish I could remember more, but that was atleast 2
>>>> years ago.  Hopefully it can lead you in the right direction.  I
>>>> think I ended up using and EFI partion table if I remember correctly.
>>>>
>>>> Judd
>>>>
>>>> Dan wrote:
>>>>
>>>>         
>>>>> What concerns me is if I just try and make a single 4.54TB partition
>>>>> as reiserfs without using LVM2 and mount it, it still only shows up
>>>>> as ~560GB using df -h.  This makes me think it maybe an os issue.
>>>>> Any thoughts?
>>>>>
>>>>> Barnaby Claydon wrote:
>>>>>
>>>>>           
>>>>>> Dan wrote:
>>>>>>
>>>>>>             
>>>>>>> I have 24 - 500GB drives raided such that 11 drives + 1 hot spare
>>>>>>> per raid to get 4.54TB times 2.  I want to use LVM2 to make this
>>>>>>> into one ~9TB disk, but when I create the partitions and do a df
>>>>>>> -h they show up as about 560GB each instead of 4.5TB each.  I do
>>>>>>> an fdisk -l and they show up correctly.  I am using Slackware
>>>>>>> 10.0.  I have device-mapper and LVM2 correctly installed.  I am
>>>>>>> obviously hitting a 2TB limit from what I have read, but does
>>>>>>> anyone know if it is possible to even do what I want?  If so, any
>>>>>>> suggestions on what I need to install to get this to work?  I am
>>>>>>> running the 2.6.15.4 kernel.  Thanks
>>>>>>>
>>>>>>>               
>>>>>> Dan, from the LVM2 FAQ (
>>>>>> http://www.tldp.org/HOWTO/LVM-HOWTO/lvm2faq.html ) it mentions:
>>>>>>
>>>>>> * For 32-bit CPUs on 2.6 kernels, the maximum LV size is 16TB.
>>>>>> * For 64-bit CPUs on 2.6 kernels, the maximum LV size is 8EB. (Yes,
>>>>>> that is a very large number.)
>>>>>>
>>>>>> From what I recall when I built my last LVM, it's a matter of
>>>>>> setting the PE size during creation (hopefully you haven't started
>>>>>> filling with data yet). I think the default causes you to hit the
>>>>>> 2TB limit, but it can definitely be set higher. The default PE Size
>>>>>> seems to depend on Linux distribution, but mine is at 4MB and I'm
>>>>>> at 1.5TB right now so the references to a 32MB default would
>>>>>> definitely get you to 9TB.
>>>>>>
>>>>>> Sorry I can't offer any other specifics - hope that helps.
>>>>>>
>>>>>> -Barnaby
>>>>>>
>>>>>>
>>>>>> _______________________________________________
>>>>>> linux-lvm mailing list
>>>>>> linux-lvm at redhat.com
>>>>>> https://www.redhat.com/mailman/listinfo/linux-lvm
>>>>>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>>>>>>             
>>>>> _______________________________________________
>>>>> linux-lvm mailing list
>>>>> linux-lvm at redhat.com
>>>>> https://www.redhat.com/mailman/listinfo/linux-lvm
>>>>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>>>>>           
>>>>
>>>>         
>>> _______________________________________________
>>> linux-lvm mailing list
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>>> https://www.redhat.com/mailman/listinfo/linux-lvm
>>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>>>       
>> _______________________________________________
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>>
>>     
>
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>   