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* imsm: 32 bit sector counts and > 2TB disks
@ 2012-12-13 16:45 Phillip Susi
  2012-12-13 17:08 ` John Robinson
  0 siblings, 1 reply; 3+ messages in thread
From: Phillip Susi @ 2012-12-13 16:45 UTC (permalink / raw)
  To: Linux RAID

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It appears that the imsm format only uses 32 bits to represent the
sector counts used from each disk.  It appears that at least on
Windows, a disk > 2 TB works so could someone from intel explain how
this is supposed to work?

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^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: imsm: 32 bit sector counts and > 2TB disks
  2012-12-13 16:45 imsm: 32 bit sector counts and > 2TB disks Phillip Susi
@ 2012-12-13 17:08 ` John Robinson
  0 siblings, 0 replies; 3+ messages in thread
From: John Robinson @ 2012-12-13 17:08 UTC (permalink / raw)
  To: Phillip Susi; +Cc: Linux RAID

On 13/12/2012 16:45, Phillip Susi wrote:
> It appears that the imsm format only uses 32 bits to represent the
> sector counts used from each disk.  It appears that at least on
> Windows, a disk > 2 TB works

It certainly does. I built a Supermicro server with 3TB drives and IMSM 
RAID a couple of weeks ago.

> so could someone from intel explain how
> this is supposed to work?

I'd be interested too. If I need to expand the array on the above, I was 
expecting to use a Linux live CD and mdadm to do the reshape.

Cheers,

John.


^ permalink raw reply	[flat|nested] 3+ messages in thread

* RE: imsm: 32 bit sector counts and > 2TB disks
       [not found] <679865E03F4C71419D9847EA3AACB1631620DDC8@IRSMSX102.ger.corp.intel.com>
@ 2012-12-17 13:03 ` Dorau, Lukasz
  0 siblings, 0 replies; 3+ messages in thread
From: Dorau, Lukasz @ 2012-12-17 13:03 UTC (permalink / raw)
  To: Phillip Susi, John Robinson, linux-raid@vger.kernel.org; +Cc: Czarnowska, Anna

On Thursday, December 13, 2012 10:08 AM John Robinson wrote:
> On 13/12/2012 16:45, Phillip Susi wrote:
> > It appears that the imsm format only uses 32 bits to represent the
> > sector counts used from each disk.  It appears that at least on
> > Windows, a disk > 2 TB works
> 
> It certainly does. I built a Supermicro server with 3TB drives and IMSM RAID a
> couple of weeks ago.
> 
> > so could someone from intel explain how this is supposed to work?
> 
> I'd be interested too. If I need to expand the array on the above, I was
> expecting to use a Linux live CD and mdadm to do the reshape.
> 

The IMSM metadata uses 64 bits to represent sizes (saved in *_lo and *_hi parts 32 bits each):

http://git.neil.brown.name/git?p=mdadm.git;a=commitdiff;h=5551b113dc18a6275fb04c7e7e3b76c656926e0a

Lukasz


^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2012-12-17 13:03 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2012-12-13 16:45 imsm: 32 bit sector counts and > 2TB disks Phillip Susi
2012-12-13 17:08 ` John Robinson
     [not found] <679865E03F4C71419D9847EA3AACB1631620DDC8@IRSMSX102.ger.corp.intel.com>
2012-12-17 13:03 ` Dorau, Lukasz

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