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Re: Blueprint created: LocalFS Class

To: "Vineeth Pillai" <Vineeth.Pillai@xxxxxxxxxxx>, <openstack@xxxxxxxxxxxxxxxxxxx>
From: "Caitlin Bestler" <Caitlin.Bestler@xxxxxxxxxxx>
Date: Fri, 16 Sep 2011 10:45:52 -0700
Thread-index: AcxzyhiYXDAmm1jzR+2+JoNyFlFTawAw9ZCgAAJuGGA=
Thread-topic: Blueprint created: LocalFS Class

Vineeth Pillai wrote:

> Rather I feel that, this information can be provided at the time of
adding devices. As of now, the format for adding
> device is z<ZONE ID>-<IP>:<PORT>/<DEVICE>

>This can be modified as:
>z<ZONE ID>-<IP>:<PORT>/<DEVICE>[:<MIRROR COUNT>]

The etherpad proposal has been modified to detail how Ring building
would need to be modified, reflecting the
above strategy. When assigning devices to satisfy a replica count
requirement two rules would be followed:
* One device can never provide enough replicas by itself.
* Devices with mirrors are only credited to the minimum number of
mirrors of the devices assigned. So if 7
   Replicas are called for and three devices have been assigned with 3,
2 and 2 mirrors another device is still
   needed. Three * the minimum  (2) is only 6. In realistic number this
means that three replicas cannot be
   Satisfied with two devices only one of which has mirroring, because
loss of the mirrored device would
   Instantly degrade to only having a single physical replica on the
network.