Accessing SCSI-Devices >2TB

[Bernd Walter]

On Wed, Jun 08, 2005 at 04:08:37PM +0200, Raphael H. Becker wrote:
> On Wed, Jun 08, 2005 at 06:36:48AM -0500, Eric Anderson wrote:
> > Raphael H. Becker wrote:
> > > I tried to attach our new external RAID to my RENEG_5_4 box today using
> > > one logical drive of about 2326GB. 
> > > 
> > > The RAID was preconfigured with two 50% partitions which were assigned 
> > > to two LUNs. FreeBSD 5.4 was able to detect those as da1 and da2 with 
> > > full capacity. 
> 
> I used plan b (see below) and reverted back to 2 LUNs each mapped to one 
> partition of the logical drive.
> 
> After the RAID-initialisation (it does some background-init) I was able
> to get those drives as da1 and da2 using "camcontrol rescan ...":
> 
> da1 at ahc1 bus 0 target 0 lun 0
> da1: <IFT A12U-G2421 342D> Fixed Direct Access SCSI-3 device
> da1: 160.000MB/s transfers (80.000MHz, offset 127, 16bit), Tagged Queueing Enabled
> da1: 1310177MB (2683242496 512 byte sectors: 255H 63S/T 167024C)
> da2 at ahc1 bus 0 target 0 lun 1
> da2: <IFT A12U-G2421 342D> Fixed Direct Access SCSI-3 device
> da2: 160.000MB/s transfers (80.000MHz, offset 127, 16bit), Tagged Queueing Enabled
> da2: 1310177MB (2683242496 512 byte sectors: 255H 63S/T 167024C)
> 
> Did a simple 
> 
> ccdconfig ccd0 64 none /dev/da1 /dev/da2 
> 
> (Kernel with "device ccd") then to get a /dev/ccd0. Works.
> 
> > > b) reverting to 2 Partitions and doing ccd(4) on the resulting /dev/da(1|2)
> > This is what I did (using gvinum).
> 
> How to get disklabel running with this?

Use gpt to partition - which was already mention in this thread.
disklabel won't do and since gpt was already widely accepted there
was not reason to have a new disklabel.

> # disklabel ccd0
> disklabel: disks with more than 2^32-1 sectors are not supported
> 
> I'm afraid I  need to use fdisk to split my ccd'ed RAID again to get two
> smaller partitions. So, this is exactly what I've done in the
> RAID controller: RAID'ing 12 Drives to a logical drive, split them up
> into 2 Partitions and assigning two LUNs to get two drives for FreeBSD,
> ccd'ing them to one drive and finally splitting it up into two
> partitions using fdisk. :-/
> This would effectivly save me an fdisk and a ccd(4) and some trouble.
> 
> Any idea, how to get 2620354MB in one filesystem (using the two ccd'ed
> partitions of the RAID)?
> 
> Well, I'm pretty trained in configuring that RAID now so if anyone knows 
> a solution, how to get rid of the 2TB-Limit for one drive (/dev/da1),
> maybe using larger blocks of about 1k or 2k, I just need to configure
> that RAID as a single large logical drive. 

There is no such limit.

-- 
B.Walter                   BWCT                http://www.bwct.de
bernd at bwct.de                                  info at bwct.de