kernel recognizing large (> 2.1 TB) block devices ?

Peter Arremann loony at loonybin.org
Sun Jan 16 01:43:35 UTC 2005


On Thursday 13 January 2005 13:08, Randall A. Jones wrote:
> This SCSI card is an Adaptec 39160.
> The RAID is a Nexsan ATABoy2 with a SCSI interface.
> It seems that the driver recognizes the need and is trying to use the
> READ(16) command but that it is failing.
> from log:
>
> sdc : very big device. try to use READ CAPACITY(16).
> sdc : READ CAPACITY(16) failed.
>
> I'm assuming the Nexsan device will work correctly given a capable
> controller and OS/driver. It has a special mode that allows >2.1TB LUNs to
> be created.  The default system config only allows for 2199023 MB LUNs
> (~2.1TB).
> Nexsan engineers don't have a firm answer for me on this issue.  They are
> not aware of any of their customers using a LUN this large on their device
> but they say it should work given a capable system.
>
> I can put a Fiberchannel controller in the ATABoy2 RAID unit.  Then connect
> to a Fiberchannel HBA on the server.  Is it possible that there is a
> capable FC HBA that can do SCSI-3 and 16byte SCSI commands properly to
> handle the large device? I have a QLogic 2342 HBA on hand and the specs for
> the card state that it has "SCSI-3 Fibre Channel Protocol (SCSI-FCP)"
> "compliance".  Is it possible this will work?
>
> I've heard that LSI might have a similar capability.
>
> Thanks for the info and discussion.
>
> Randall

Randall,

We got a 3.4TB raid running on a LSI controller - unfortunately not with 
Linux.  But at least that way I know the 16byte command support works on the 
card. Since QLogic and their oems like sun never say anything about these 
capabilities I doubt that it works there...
Oh, the LSI press release is at: 
http://www.infortrend.com/%5CNews%5C20041006%5Cf_64Bit_LBA.htm
and mentions the 2.6 kernel...

Peter.




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