Re: large file system with RAIDframe

[mlelstv%serpens.de@localhost (Michael van Elst)]

smb%cs.columbia.edu@localhost (Steven Bellovin) writes:

>The question, though, is how wedges interact with RAID.  As best I can =
>tell, there are no wedges on RAID5 "volumes" -- how are partitions =
>assigned, if not via disklabel?=20

Manually with dkctl or by a disklabel of some kind (e.g. GPT) and automatic
generation of wedges with DKWEDGE_AUTODISCOVER and DKWEDGE_METHOD_GPT.

N.B. Don't use DKWEDGE_METHOD_MBR or DKWEDGE_METHOD_BSDLABEL unless
you are prepared to access all disks only with wedges.


># dkctl raid1 getwedgeinfo=20
>dkctl: /dev/rraid1d: getwedgeinfo: Inappropriate ioctl for device

This would be dkctl raid1 listwedges. getwedgeinfo is used to get
data from the wedge (dk0,dk1,...) itself.

# dkctl sd0 listwedges
/dev/rsd0d: 3 wedges:
dk0: 72a45a52-09c5-11df-bed3-001cc4d779ed, 16000000 blocks at 18, type: swap
dk1: 72a45a70-09c5-11df-bed3-001cc4d779ed, 200000000 blocks at 16000018, type: 
ffs
dk2: 72a45a8e-09c5-11df-bed3-001cc4d779ed, 28198549 blocks at 216000018, type: 
lfs

# dkctl dk2 getwedgeinfo
dk2 at sd0: 72a45a8e-09c5-11df-bed3-001cc4d779ed
dk2: 28198549 blocks at 216000018, type: lfs


I haven't tried wedges on raid(4) myself.

-- 
-- 
                                Michael van Elst
Internet: mlelstv%serpens.de@localhost
                                "A potential Snark may lurk in every tree."