[linux-lvm] Lvm RAID0 vs lvm striping

[linux-lvm] Lvm RAID0 vs lvm striping

[John Ratliff]

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What is the difference between these two?

 

Thanks.

 

John Ratliff


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Re: [linux-lvm] Lvm RAID0 vs lvm striping

[Chris Murphy]

On Wed, Jul 3, 2019 at 2:33 AM John Ratliff <jdratlif@globalnoc.iu.edu> wrote:
>
> What is the difference between these two?
>

If the question is about segment type, raid0 and raid1 use the md
driver code (same kernel code the mdadm raid uses, but is managed with
LVM metadata and user space tools). And striped and mirror use an
internal implementation, although I'm not sure if this is internal to
LVM or device-mapper, and I think are considered legacy at this point.

'man 7 lvmraid' doesn't directly answer your question but contains
quite a lot of information about lvmraid. It does explicitly say to
use raid1 over mirror segment type. It doesn't say that about raid0 vs
stripe segment type, maybe the two implementations aren't all that
different but anyway I would use raid0.



-- 
Chris Murphy

Re: [linux-lvm] Lvm RAID0 vs lvm striping

[Heinz Mauelshagen]

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This is both striping via 2 different, supported device-mapper targets, 
'striped' and 'raid'
('striped' is  an older, separate target and  'raid0' is supported by 
the 'raid' target which
  also supports raid1/raid4/raid5/raid6 and raid10).

The algorithm to distribute data on the stripes is the same for both 
striped and raid0
and they can be converted into each other running 'lvconvert --type 
striped|raid0 $LV'
since raid target version 1.7.0 / lvm2 version 2.02.155.

See lvmraid(7) for insight into the RAID support in lvm including the 
aforementioned
and many more conversions from and to RAID and between RAID levels and 
layouts..

Heinz

On 7/2/19 5:53 PM, John Ratliff wrote:
>
> What is the difference between these two?
>
> Thanks.
>
> John Ratliff
>
>
> _______________________________________________
> 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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