PFS mirroring insted of RAID Improved set up - need comments.

[Siju George]

Hi,

In my previous setup I replaced and OpenBSD machine on RAIDFRAME (
mirroring 2 120GB Disks ) with dragonfly development version mirroring
Data from one disk to other. In the setup the System and packages are
all installed to small UFS partitions and the Data is on a PFSes that
are on two large hammer partitions on the disks. So the Data is
mirrored using mirror-stream but the system is kept up to date
manually by mounting the UFS partions on the second disk and doing the
same tasks that are done to the system on the first disk after
chrooting.

Now this is a little bit tedious so I wonder If I can improve the
setup a little bit now that I am going to Replace a FreeBSD Samba
Domain Controller/Apache/MSQL/Subversion Server with the dfly
development version..

These are the steps I think of following.

1) Install DragonFly to bots disks using only hammer file system.
2) Boot into First hard Disk
3) Create a PFS 'pkg' for /usr/pkg to comtain all pkgsrc and related stuff
4) Destroy the PFSes ( home, tmp, usr, var ) in Second Disk.
5) Recreate Slave PFSes for "home, tmp, usr, var, pkg" ) on the second
Disk and mirror them using mirror-stream from the corresponding PFSes
from first disk.
5) After Installing Updates to dfly system or pacakges on the first
disk rsync from / to the second Disk using the --exclude option to
exclude home, tmp, usr, var, pkg directories ( PFSes )

Is this OK? Will I have a Identical System on my Second Dsik? Of
course if the first Disk fails then I will have to plug its cable to
the second Disk so that device numbering is correct. and upgrade the
slave PFSes to master inorder to continue but I guess it will take
less that 10 mins?

How will I update the boot code on the second Disk?

I guess mirroring will not spread file system corruption on first disk
to the second Disk as in RAID ?

Another advantage I perceive is that If I configure the snapshots
right I wont need to backup Data to a backup Server since I will have
the required versions :-)

Thanks

 --Siju