From: UnixMgr (unixmgr@bowater.com)
Date: Mon Mar 22 2004 - 13:06:05 EST
I have a system (alphaserver 4100) that was excess at one site that we
plan to use here. I went into the raid array utility and set up the
shelves as follows: (each shelf holds six drives)
Controller 1
Log drive 0 sh1 shelf2
[4gb] [4gb]
[4gb] [4gb]
[4gb] [4gb]
[4gb] [4gb] This is raid 0 + 1 and shows a
size of 32768 mb from controller software
Log drive 1
[4gb] [4gb]
[4gb] [4gb] This is raid 0 + 1 and shows a
size of 16364 mb from controller software
Controller 2
Log drive 0
[4gb] [4gb]
[4gb] [4gb]
[4gb] [4gb] This is raid 0 + 1 and shows a
size of 24546 mb from controller software
Log drive 1
[9.1gb] [9.1gb]
[9.1gb] [9.1gb]
[9.1gb] [9.1gb] This is raid 0 + 1 and shows a
size of 52068 mb from controller software
My goal was to stripe each shelf and then mirror it with an equivalent
config on the other shelf for redundancy. Here is where I got confused,
I booted from install cd and then exited out so that I could do
disklabels. (Goal is to migrate copy of existing environment) I did
disklabel -rw on each dsk device to get a basic label.
Dra0 shows up as an 8 member, this should be controller 1, log drive 0.
A disklabel -r dsk0 shows a c partition of 33,513,472. This seems
consistent with 32,728 mb as reported.
Dra1 shows up as a 4 member, this should be controller 1, log drive 1.
A disklabel -r dsk1 shows a c partition of 16,756,736. This is also
consistent with the 16,364 mb size that was reported.
Drd0 shows up as a 6 member, this should be controller 2, log drive 0.
A disklabel -r dsk4 shows a c partition of 17,773,524. This does not
make sense to me. The reported size in the controller was 24,546 mb.
There is too much difference here.
Drd1 shows up as a 6 member, this should be controller 2, log drive 1.
A disklabel -r dsk5 shows a c partition of 8,380,080. This is even more
puzzling.
I have rerun the controller config to verify what I wrote down. I don't
know if maybe my understanding of what I should see is wrong or what but
the numbers on one controller seem to be what I would expect, the other
one does not. Also, even though the controller says these are raid 0 +
1 and the boot shows it, I still am confused that the total size seems
to be the size of all drives not the logical size of the raid 0 + 1
device. I would expect the c partition for a raid 0 + 1 containing six
4gb drives to be 12gb.
Michael Smith
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