On Tue, Oct 11, 2011 at 03:23:16PM -0400, Jiri B wrote: > theo@ doomed ccd - http://marc.info/?l=openbsd-cvs&m=131805777910632&w=2 - > and Michal asked what could be replacement for ccd and got no reply - > - http://marc.info/?l=openbsd-cvs&m=131805777910645&w=2. > > Do devs want to put ccd-like spanning volume feature into softraid or > what would be similar feature in OpenBSD in the future?
OpenBSD can concatenate devices without ccd two ways that I can think of. I think one could reproduce ccd's concatenation of dissimilar sized disks via the RAID 0 discipline and using BSD partitioning with a partition size that is a factor of the various disk sizes you're interested in. For example, to concatenate a 1-TB disk with a 2-TB disk, you merely need to have three 1-TB partitions in your bioctl(8) device list for softraid(4), or your raidctl(8) config_file for raid(4) while RAIDframe remains available. This is probably beyond what you were looking for, but AFS has logical volume management baked right in, as AFS file servers can be quite distributed yet still provide a seamless storage pool. AFS client software from Arla is in the base; net/openafs is the server software. I think, though, that this may be too much complexity and overhead for use as a local solution. Since softraid is extensible with disciplines, a concatenation discipline could be written, though I think with a little planning, RAID 0 could meet needs. I'm not a developer, and couldn't answer if such a discipline is planned. I would suspect that patches to add such a discipline would be given appropriate consideration.
