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Assigning LUN to Host group?
Hello,
Thanks in Advance,
please i have an issue while assigning lun to host group.
I Have Dell Storage 3800 Series and have two dell power edge r530 with Red hat enterprise licence.
i have created 4 virtual disk, host group and two host are assigned to the group.
now , i have mapped 4 virtual disk to the host group and now its showing:-
Access lun 31, lun1, lun2,lun3 and lun4.
The all assigned disk can be visible on both the servers.
now i want if i copy data into the server1 on a mapped drive it should show onto the server2 same mapped drive but it does not show. because all hard drive are assigned to host group so it should be common isn't ?
is there any things needs to be done?
second:-
i want to ask you once the drive are showing on the server what should i do to mount it properly on linux its just the way i am doing going to the application/utility/disk and then advance/mounting point changing to /processor from /mnt/146595d3232d478982100364d (default one)
is the right way i am doing it or any other way i need to do it.
Dev Mgr
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May 8th, 2017 20:00
The MD3800 is a SAN, not a NAS.
This means that to share storage you need to use a disk locking mechanism of some sort to regulate which server can write to which (part of which) disk when.
Typical options for this is a cluster solution (e.g. RedHat's GFS, Microsoft Cluster Services, etc), or a cluster aware filesystem (e.g. VMware's VMFS).
Mounting the same disk on 2 servers without such a mechanism will cause data corruption and server stability issues as one server will eventually overwrite data that the other server wrote to the disk (as the servers don't have a mechanism to let eachother know the other server can take control of the disk).
To test the ability to have both servers access a disk, have only 1 server mount it, write some test data, then unmount it, let the other server mount it (it will now read the file allocation table (or equivalent for the filesystem of your choice) and be aware of the latest state of the data on the disk), and your data should be there.