[linux-lvm] Linux LVM online shrinking :(

[linux-lvm] Linux LVM online shrinking :(

[DILIP KURUMANGHAT]

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Hi Team,

You might already have come across this stuff many a times.

I am sending this query as to why LVM is not supporting online shrink.
How is that AIX can do the shrink but not in our best Linux.

Is there a big difference i the underlying architecture which prevents us
from an online shrink?

Thanks and regards,
DILIP K

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Re: [linux-lvm] Linux LVM online shrinking :(

[Zdenek Kabelac]

Dne 1.8.2013 11:00, DILIP KURUMANGHAT napsal(a):
> Hi Team,
>
> You might already have come across this stuff many a times.
>
> I am sending this query as to why LVM is not supporting online shrink.
> How is that AIX can do the shrink but not in our best Linux.
>
> Is there a big difference i the underlying architecture which prevents us from
> an online shrink?
>

You are asking this question on a wrong mailing list.

LVM2 of course does fully support online device shrink.

The other side of story is - there is no filesystem I'd know about which
would be supporting online shrinking.  The fact is - it's pretty hard
to do and there are not many people interested in this feature - so I'd
not expect it would be written i.e. for ext4 anytime soon
(Since you could easily do that offline).


Zdenek

Re: [linux-lvm] Linux LVM online shrinking :(

[Zdenek Kabelac]

Dne 5.8.2013 10:53, Zdenek Kabelac napsal(a):
> Dne 1.8.2013 11:00, DILIP KURUMANGHAT napsal(a):
>> Hi Team,
>>
>> You might already have come across this stuff many a times.
>>
>> I am sending this query as to why LVM is not supporting online shrink.
>> How is that AIX can do the shrink but not in our best Linux.
>>
>> Is there a big difference i the underlying architecture which prevents us from
>> an online shrink?
>>
>
> You are asking this question on a wrong mailing list.
>
> LVM2 of course does fully support online device shrink.
>
> The other side of story is - there is no filesystem I'd know about which
> would be supporting online shrinking.  The fact is - it's pretty hard

Except for btrfs - which on the other hand doesn't need  lvm2.
So if you need something shrinkable online - try to go with btrfs.

Zdenek

Re: [linux-lvm] Linux LVM online shrinking :(

[Heinz Mauelshagen]

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On 08/01/2013 11:00 AM, DILIP KURUMANGHAT wrote:
> Hi Team,
>
> You might already have come across this stuff many a times.
>
> I am sending this query as to why LVM is not supporting online shrink.
> How is that AIX can do the shrink but not in our best Linux.

Hi,

how do you come to this conclusion?

LVM supports online shrinking of logical volumes since LVM1 got 
introduced back in 1997?

Maybe you're confusing this with filesystens or applications string data 
on logical volumes
not being able to online shrink?

>
> Is there a big difference i the underlying architecture which prevents 
> us from an online shrink?

No.

Heinz

>
> Thanks and regards,
> DILIP K
>
>
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@redhat.com
> https://www.redhat.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/


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Re: [linux-lvm] Linux LVM online shrinking :(

[Mauricio Tavares]

On Mon, Aug 5, 2013 at 5:01 AM, Zdenek Kabelac <zkabelac@redhat.com> wrote:
> Dne 5.8.2013 10:53, Zdenek Kabelac napsal(a):
>
>> Dne 1.8.2013 11:00, DILIP KURUMANGHAT napsal(a):
>>>
>>> Hi Team,
>>>
>>> You might already have come across this stuff many a times.
>>>
>>> I am sending this query as to why LVM is not supporting online shrink.
>>> How is that AIX can do the shrink but not in our best Linux.
>>>
>>> Is there a big difference i the underlying architecture which prevents us
>>> from
>>> an online shrink?
>>>
>>
>> You are asking this question on a wrong mailing list.
>>
>> LVM2 of course does fully support online device shrink.
>>
>> The other side of story is - there is no filesystem I'd know about which
>> would be supporting online shrinking.  The fact is - it's pretty hard
>
>
> Except for btrfs - which on the other hand doesn't need  lvm2.
> So if you need something shrinkable online - try to go with btrfs.
>
      btrfs is not the only one; I just cannot remember of the ones
you can use with lvm2. I mean, ext(1,2,3,4) do not like to be sized
down live and just like btrfs, zfs and jfs2 (at least on AIX) do not
need lvm2. But, you can use jfs in linux.

Ok, I need coffee.


> Zdenek
>
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@redhat.com
> https://www.redhat.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/