[Crowbar] disk management and partitioning concepts

[Dae Woo]

Thanks! Shame on me, I never looked at Swift and Hadoop barclamps.

So, if I understand correctly all additional disk management occurs only
when it is really needed by a appropriate barclamp. That's good.

I'm just looking at nova-volume recipes and discovered that it uses regular
file for a logical volume group. I'm thinking about separate
nova-volume-server role and the recipe that can make volume group on the
real disks, not files.

On Thu, Mar 15, 2012 at 6:49 PM, <Andi_Abes at dell.com> wrote:

> So, Crowbar does manage the additional disks, when it needs too.
> So both Hadoop and Swift look for any available drives, and will setup
> them up based on their requirements, when a node is configured to be part
> of a swift or hadoop data node (the filesystem params are somewhat
> different between hadoop and swift). Both discover the available disks,
> filter out disks that are otherwise used, and then configure them.
>
> This is in-line with Crowbar's devOps principles - build what you need
> when you need it.
>
> As for RAID, yes. There is a proprietary barclamp, which can configure a
> node as either:
>
> *         RAID 10 - where the OS seems just 1 big drive.   This is used
> for workloads (or Roles) that need reliable storage, and doesn't handle
> disk failures well.
>
> *         JBOD - for workloads that are smart (ish)about handling disks
>
> Configuring the appropriate role also follows devOps - configure the raid
> when you know what it needs to be, based on what the node is going to do.
>
> So, your proposal of configuring all the disks upfront could be a bit
> problematic. When installing the OS, we don't really know enough about how
> to setup the additional disks (e.g. swift likes XFS)
>
>
> All that said and done... what are you trying to get done or deployed?
> Does it have any requirements for the filesystem that the component
> consumes?
>
>
>
> From: crowbar-bounces On Behalf Of Dae Woo
> Sent: Thursday, March 15, 2012 10:32 AM
> To: crowbar
> Subject: [Crowbar] disk management and partitioning concepts
>
> Hello,
>
> it is very interesting how crowbar is doing partitioning and disk
> management. I'm guessing that it can configure RAID on the unallocated
> nodes with the help of proprietary barclamp.
>
> Is the configured RAID storage visible to the operating system as only one
> existing disk?
>
> Anyway, for ubuntu distros crowbar is using preseed with the atomic
> partitioning scheme with LVM. It uses the whole disk /dev/sda and creates
> only 2 volume groups: for root and a swap. But if we have some more disks,
> e.g. /dev/sdb, /dev/sdc, it leaves them untouched at all.
>
> In fact crowbar has no any adjustable method to perform the disk/'logical
> volume' management and partitioning.
>
> My suggestion is to perform this management step during the operating
> system installation.
> Sledgehammer will provide all information about every unallocated node
> during the discovery state by ohai. And then when a specific proposal is
> being applied barclamp-provisioner can adjust preseed configuration to make
> some logical volume management and partitioning. This disk configuration is
> depends on the actual role assigned to the node.
>
> Do you have any future plans/ideas/thoughts on this?
>
>
>
> Many thanks!
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.us.dell.com/pipermail/crowbar/attachments/20120315/6e089b2e/attachment-0001.html