ccd

hw-tph · 08-12-2005, 04:21 AM

I am trying to set up two identical IDE disks as concatenated disks in OpenBSD. They work fine like regular disks, but I cannot manage to get the size of the ccd to span across both disks - whatever I do the size of the resulting ccd seems to be equal to the size of *one* of the disks.

Code:

wd1 at pciide0 channel 0 drive 1: <SAMSUNG SV6004H>
wd1: 16-sector PIO, LBA, 57278MB, 117306000 sectors
wd1(pciide0:0:1): using PIO mode 4, Ultra-DMA mode 2
(...)
wd2 at pciide0 channel 1 drive 0: <SAMSUNG SV6004H>
wd2: 16-sector PIO, LBA, 57278MB, 117306000 sectors
wd2(pciide0:1:0): using PIO mode 4, Ultra-DMA mode 2

I have created identical partitions using fdisk on the two disks:

Code:

  a:     117305937            63     ccd                   # Cyl     0*-116374
  c:     117306000             0  unused      0     0      # Cyl     0 -116374

I have experimented with different ileave size (16 and 32) and all the available flags according to ccdconfig(8), but none of them seem to just concatenate the partitions into one big ccd. This is an example of the many commands I have used: ccdconfig ccd0 32 0 /dev/wd1a /dev/wd2a

Did I miss something really obvious?

Håkan

hw-tph · 08-12-2005, 06:13 AM

Oh darnit. Other problems. I'll go somewhere private and curse loudly for a while.

Håkan

danielanson · 08-12-2005, 05:39 PM

From what it sounds, you are trying to set up a RAID-0. Do realize that if one disk fails, due to being old or the added stress on the disks, you will lose ALL data on both disks. I would suggest buying a IDE-RAID card to configure the disks if you really want to use IDE or cannot afford to upgrade to SCSI. If you cannot afford the upgrade, make sure and have a backup solution in place to protect your data.

-Hardware monkey D

danielanson · 08-12-2005, 05:42 PM

You may double check but it sounds as if ccd is producing a RAID-1 setup by default which it is what you are getting.

HMD

danielanson · 08-12-2005, 05:58 PM

From OpenBSD FAQ section 11

"This allows you to join several partitions into one virtual disk (and thus, you can make several disks look like one disk)."

You need to use the raid pseudo-device.

From the same page

"Another solution is raid(4), which will have you use raidctl(8) to control your raid devices. OpenBSD's RAID is based upon Greg Oster's NetBSD port of the CMU RAIDframe software. OpenBSD has support for RAID levels of 0, 1, 4, and 5.

With raid, as with ccd, support must be in the KERNEL. Unlike ccd, support for RAID is not found in GENERIC, so it must be compiled into your kernel (RAID support adds some 500K to the size of an i386 kernel). "

page: http://www.openbsd.org/faq/faq11.html

Look at the raid man pages. Best of luck!!

-HMD