[Linux-HA] 2 IBM ServeRAID 4Mx with exp300

[Alan Robertson]

Joshua Koontz wrote:
> Alan Robertson wrote:
> 
>> Joshua Koontz wrote:
>>
>>>
>>> This may be slightly OT, but from what I've read and seen in the 
>>> archives there may be somebody here who could help me.
>>>
>>> My hardware consists of 2 x345 servers each with a serveRAID 4Mx scsi 
>>> card attached to an exp300 disk array.  I currently have one server 
>>> set active and able to access the exp300 while the other is a 
>>> backup.  I've written my own shell scripts using the ipssend command 
>>> that will set the drives ( 6 drives in a Raid 5 configuration) 
>>> offline on the active server and that will set the drives online on 
>>> the backup server.  Here is a quick synopsis:
>>>
>>> On active server:
>>>
>>> Umount array
>>> Mark all of the 6 drives defunct/offline
>>> Reboot the machine
>>>
>>> On backup server:
>>>
>>> Mark first 5 drives online (They were marked defunct)
>>> Initiate a rebuild on 6th drive
>>> Reboot the machine
>>>
>>> Then the drive is visible to the backup server and is able to be 
>>> mounted.  I have the one server using scsi initiator ID 6 and the 
>>> other using ID 7.  All the data is valid.
>>>
>>> Are there any problems with doing it this way?  Is there a better way 
>>> to do this 'manual failover'?  Most of my talks to IBM hardware and 
>>> support have lead me nowhere.  I'd like to implement the HA's 
>>> failover system for my hardware in the future, but for now I'd like 
>>> to do this manually.
>>>
>>> If you need any more info, configs, scripts let me know.  Thanks for 
>>> any comments/suggestions.
>>
>>
>>
>> You might try looking at these pages linked from here:
>>     http://wiki.trick.ca/linux-ha/ServeRAID
>>
>> Our ServeRAID resource script is even "ServerProven" with heartbeat 
>> and ServeRAID.  (If you really want to use RAID 5, you'll have to hack 
>> it to allow you to use RAID5 - but that's easy).
>>
>>
> Thanks Alan, the ServeRAID resource script looks exactly like what I was 
> looking for.  It is a little different than the hack I had come up with 
> to make things work, but I'm sure this way is much better.  I think I'll 
> just use that script to allow/disallow access manually as I see fit. 
> Will that allow both servers to access the exp300 at the same time?  I 
> don't want that for now, but maybe down the road I may want to implement 
> that.  Thanks again!!

With ServeRAID it is impossible to enable access to both sides at the same 
time.

The nice thing about this is that it is impossible for your admin to make a 
mistake and destroy your filesystem.

-- 
     Alan Robertson <alanr at unix.sh>

"Openness is the foundation and preservative of friendship...  Let me claim 
from you at all times your undisguised opinions." - William Wilberforce