Re: raidframe and gpt

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

paul%whooppee.com@localhost (Paul Goyette) writes:

>> Does anyone have an example of how to configure raid0 on a GPT disk?

For a manual setup, you can just reference the wedges like:

# raidctl config file for /dev/rraid0

START array
# numRow numCol numSpare
1 2 0

START disks
NAME=raid0.0
NAME=raid0.1

START layout
# sectPerSU SUsPerParityUnit SUsPerReconUnit RAID_level_1
128 1 1 1

START queue
fifo 100


Auto detection of a RAID works by collecting disks with valid
RAID labels into RAID sets. This also works with wedges, the
actual device or unit number is irrelevant, the RAID set is
identified by the unique serial number in the RAID label.
The serial number is specified with the -I option of raidctl.

Even booting from a RAID on GPT is possible with a recent bootloader
and an autoconfigured RAID set.


Here is more about RAID on GPT:

https://wiki.netbsd.org/users/spz/moderndisk/



>> I can easily set the partition type with gpt, but how do I reserve
>> space for the raid component label?  Do I need to reserve that space?

You don't, the components are the GPT partitions.


>> Also, does raidframe understand the NAME=gpt-label syntax in the
>> config file?  Or does it require me to specify the particular dk<n> ?
>> (And what happens if something moves and <n> changes?)

I've added support for the NAME= Syntax some time ago.


>One more quuestion: the raidctl man page talks about partitioning the
>raid<n> device using mbr partitions.  Is it possible to use GPT here?
>Will the resulting wedges show up automatically?

Whenever you create a raid device (raidN attaches), it will be
scanned for wedges like a regular disk device.

# dkctl dk4 getwedgeinfo
dk4 at raid2: tank
dk4: 4294967296 blocks at 128, type: ffs

# grep tank /etc/fstab
NAME=tank       /tank           ffs     rw,log          1 2

This system configures a RAID1 of two RAID0 sets. That's not supported
by the RAID autoconfiguration, so it is created manually at boot time
and obviously the system can't boot from it.