Re: mkfs and mdadm support

[Edward Muller <emuller@engineyard.com>]

Just FYI ...

IN case your not aware...

LVM can sit on top of raid, and vice versa.
Ditto with DRBD

Basically it's a bunch of block devices that can be used by either
other in various ways.

On Tue, Jun 9, 2009 at 11:32 AM, Jeffrey Hulten<jhulten@gmail.com> wrote:
> Wouldn't raid and lvm (and drbd, etc) all be volume types? It seems that
> they all provide a device to place a filesystem on.
>
> For raw disk, sda/hda.
> For raid, md0, etc.
> For lvm, a VG which a LV is built from.
> For drbd, drbd0, etc.
>
> On Tue, Jun 9, 2009 at 10:53 AM, snacktime <snacktime@gmail.com> wrote:
>>
>> Thanks, I totally missed the -s option.  I'm looking at the best way to
>> safeguard against running mkfs on an existing filesystem.   So one of the
>> options to the provider will be a force flag of some type, and if that flag
>> is not present it will refuse to re initialize the filesystem.  mkfs isn't
>> uniform in requiring a force flag to re initialize a device that already 
>> has
>> a filesystem, so can't rely on that.
>> Chris
>>
>> On Tue, Jun 9, 2009 at 10:26 AM, Steven Parkes <smparkes@smparkes.net>
>> wrote:
>>>
>>> Don’t know if there are corner cases that don’t work, but “file –s
>>> /dev/<block_device>”
>>>
>>>
>>>
>>> From: snacktime [mailto:snacktime@gmail.com]
>>> Sent: Tuesday, June 09, 2009 10:18 AM
>>> To: chef@lists.opscode.com
>>> Subject: Re: mkfs and mdadm support
>>>
>>>
>>>
>>> That's kind of the conclusion I came to last night after thinking it over
>>> some more.  I've forked chef and started last night on the filesystem and
>>> raid resources.  Should be easy enough to re arrange if needed.
>>>
>>>
>>>
>>> Would be nice if there was an available tool for detecting filesystem
>>> types.  Best I've found so far is parsing the output of parted.  Anyone 
>>> know
>>> of a better way to handle this?
>>>
>>>
>>>
>>> Chris
>>>
>>> On Tue, Jun 9, 2009 at 9:11 AM, Miguel Cabeça <cabeca@ist.utl.pt> wrote:
>>>
>>> Hi,
>>>
>>>
>>>
>>> So maybe there should be a top level filesystem resource that contain all
>>> of this.  Even after you add resources for mkfs, lvm, raid, etc.., you 
>>> still
>>> need higher level logic to tie it all together, maybe a collection of
>>> definitions?
>>>
>>>
>>>
>>> IMHO it would be too complicated to try to fit everything into the
>>> filesystem resource.
>>>
>>> It would be simpler (famous last words) to have three resources like:
>>>  filesystem
>>>  raid
>>>  volume
>>>
>>> and combine them with definitions to achieve the complete goal (for
>>> example a xfs filesystem on top of an lvm2 volume, on top of a raid1 
>>> array)
>>>
>>> Best Regards
>>>
>>> Miguel Cabeça
>>>
>>>
>
>



-- 
Edward Muller
Sr. Systems Engineer
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