Date: Wed, 8 Jun 2005 17:24:35 +0200 From: "Raphael H. Becker" <rabe@p-i-n.com> To: Xin LI <delphij@frontfree.net> Cc: freebsd-current@freebsd.org Subject: Re: Accessing SCSI-Devices >2TB Message-ID: <20050608172435.H41471@p-i-n.com> In-Reply-To: <20050608150152.GA49080@frontfree.net>; from delphij@frontfree.net on Wed, Jun 08, 2005 at 11:01:52PM %2B0800 References: <20050608122324.C41471@p-i-n.com> <42A6D850.2070603@centtech.com> <20050608160837.E41471@p-i-n.com> <20050608150152.GA49080@frontfree.net>
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On Wed, Jun 08, 2005 at 11:01:52PM +0800, Xin LI wrote: > > 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). > > Err... You don't need to play with the drivers/CAM stuff, why not try the > natively supported gpt(8), which works great. > > - Map the RAID device to a single SCSI device > - Do a dd if=/dev/zero of=/dev/da0 bs=16384 count=16 to wipe the MBR Well, without a /dev/daX there's nothing to use gpt with. The kernel itself cannot access the RAID as a whole. See my other mail for the kernel messages. My workaround was to partition the RAID's logical disc into two partitions internally and re-concat the resulting da1 and da2 into ccd0. But this might also be a bad idea therefore ccd0 is will do stripes and the RAID will have to seek the physikal drives a lot for each (linear) access. Two solutions: a) FreeBSD can access the RAID using LBA64 and get a da1 having ~2.5TB b) I have to split the RAID on physical drive layer, having 6 disks for each logical drive (losing hot-spare (cannot divide 11 discs into 2 equal logical drives) and need a additional parity, one for each logical drive) and mapping those to two different LUNs or IDs and using the resulting 1.3TB-drives da1 and da2 with ccd(4) and then ... > - Do a `gpt create /dev/da0' to create your GPT partition table > - Do a `gpt add /dev/da0' to create a GPT partition over it > - You will now see something like /dev/da0p1, which can be used for > subsequent disklabel(8), or just newfs -U /dev/da0p1 ... will try this, if the device is clear. Thank you for the hint about gpt. Regards Raphael Becker
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