Re: [dm-devel] [PATCH] dm-thinp: new device mapper target to thin provision storage

[Heinz Mauelshagen <heinzm redhat com>]

On Tue, 2010-09-28 at 17:44 -0400, Phillip Susi wrote:
> On 9/28/2010 4:49 PM, Heinz Mauelshagen wrote:
> > 
> > These are 2 new device mapper targets "thinp" and "thinp-dev"
> > implemented in one module, which allow for thin provisioning of storage
> > on a single host from a storage pool to an arbitrary amount of devices.
> 
> How is this different than snapshotting a zero target?

Like Hanness mentioned: you can free space.

> 
> > +Create an ext4 filesystem on the thin provisioned device:
> > +mkfs -t ext4 /dev/mapper/thinp1
> 
> FYI, that tends to spend a lot of time writing hundreds of mb of zeros
> to the inode tables, allocating chunks from the backing store.  You
> might want to add -E lazy_itable_init to stop that.

Thanks for the hint, I waned to have load on the thin provisioned
devices so far for testing but will have a look at the reduced
allocations with this option.

> 
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