Thanks to all who replied.
You bet I was on the wrong track ! Fist, my original post, and then the
solutions:
------------------------- BEGIN ------------------------------------------
I want to have various advfs file domains shared (not at the same time)
between 2 alpha servers 2100 running DU 3.2D and DecSafe. I know that
DecSafe 1.3 does not have a distributed lock manager and I do NOT plan to
use a shared disk with 2 machines at the same time. All I want is that, in
the event of a crash, the surviving host mounts the shared disk and make it
available or run critical apps and be able to use data on that disk (An
Oracle database, information system programs and Polycenter Scheduler). I
use HSZ40 and my harware is correctly configured for DecSafe.
I tried something that seems to work but I wanna make sure that I used the
correct procedure and answer some questions along the way.
1) On the first machine, I created a file domain (testdmn) and a fileset
(testfs). I then mounted the fileset under /test, populated it with data
and unmounted it.
mkdir /test
mkfdmn /dev/rzb11c testdmn
mkfset testdmn testfs (I dont remember the exact syntax)
mount -t advfs testdmn#testfs /test
...create some files under /test
umount /test
2) I then logged on the second system and did the following:
mkdir /test
Q1-> mkfdmn /dev/rzb11c testdmn
Q2-> mkfset testdmn testfs (I dont remember the exact syntax)
mount -t advfs testdmn#testfs /test
play with the files created in step 1 and they seemed OK.
It looks like the mkfdmn command (Q1) doesn't destroy the existing
filedomain on the disk. I know that it creates a directory structure
somewhere but does it write something on the disk and risk destroying the
data ? Same thing for Q2.
Is that procedure OK ? I see no way of _easily_ being able to transfer the
control of the shared device to the other machine other than recreating the
exact same mount points, domain names, etc... Is this true ? If not, what
is the proper way to do this ?
P.S.: I would also like to know what happens if by error, both machines try
to acces the same shared disk. For example, if I forget to umnount it on
the 1st machine and mount it on the second one. Will that destroy data or
will the system only give me an error message stating that the device is in
use without messing things up ?
----------------------------------- END -----------------------------------
That's not the proper way to do this. You have to create the filedomain and
filesets on the first machine and then use DecSafe to create a disk service
on that machine. You tell the asemgr what disks (domains, filesets, etc..)
you want to fail over and it arranges itself to recreate it on the other
system as needed.
As for both machine trying to access the same disks simultaneously, DO NO
TRY THIS: That would mess the things up ! DecSafe uses the SCSI RESERVE
command to reserve the disk and make it unavailable to the other hosts in
the cluster automatically.
Also, when I created the filedomain on the other machine, it could have
destroyed the data. In fact, it should have done this but that did not
happen. Anyway, that was a BAD idea.
THANKS AGAIN
Received on Tue Sep 24 1996 - 22:09:05 NZST