Re: Accessing SCSI-Devices >2TB

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?

# 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. 

Just tell me about the blocksizes (see other mail).

Regards
Raphael Becker