SSD drivers and SRDF setup

Question

Here is one interesting scenario.SRDF setup with R1 and R2,ClonesC1,C2 on each side.Planning to use the host on C2-side to access the data on a dial basis to perform backups or to do some tests. Since the LUN ID are more than 255 allocated on the FAs,Solaris host want to install the ssd drivers. Initial plan was to use sd.conf file to control which devices can be accessed by the servers(Either clones or Primary volumes).In this case since ssd driver discovers the storage dynamically,how would i be able to control,which device need to be accessed?Is there any static method? Reason for doing that way is,If i mask primary and Clone volumes to FA then ssd will discover both but while importing the volume groups to solaris,it would get confused to which disks to use since both of them will have same Private regions. Any thoughts/ ideas will be appreciated..

Allen Ward · Answer

This isn't really Solaris specific, but our solution for our DR environment (where we need to access R2s or Clones) involves scripts to change the masking from the Clones to the R2s and back again.

We normally leave our R2s masked for DR activation. If we run a DR test we switch to masking the Clones. Once the test is completed we revert back to the R2s mapped. It's a bit of a pain to set up, but once it is it just needs to be maintained.

srichev · Answer

Other than masking and unmasking,Is there file like sd.conf to modify on the host side for ssdf configuration.Everyday Clone volumes on the R2 side needs to be accessed.

xe2sdc · Answer

SSD driver can't be 'tweeked' via sd.conf file .. thus if you have more then 255 devices, you have to either1) map on more ports .. (map half of the devices on a couple of FA ports and another half on another pair of FA ports. If possible bring FA ports online/offline to filter devices. Otherwise change masking (!!!!) to filter devices.2) map all devices on a single pair of port and use lun offsett to filter devices3) map all devices on a single pair of ports and use masking to filter devicesI don't see too many options here ... :-/

srichev · Answer

Thanks for moving the thread here.Not familar with Lunoffset ..Can you point me to some where?This is a solaris environment.

This is another option i am thinking...May be using veritas exclude file to list the disk that needs to be excluded on the host.

xe2sdc · Answer

Srichev this thread was already here .. I simply locked the other one (in Symmetrix area) and put a line advertising this one

The thread may stay here or move itself in Symmetrix area depending on your taste .. Tell me what you prefer and I'll move the thread if needed.

Use Veritas Exclude file ?? Never used it .. I work for EMC and tend to talk about EMC stuff

I'll try to find a thread dealing with lun offsett .. check back soon !!

srichev · Answer

Leave the thread here.Not sure on yout second point. 2) map all devices on a single pair of port and use lun offsett to filter devices.BY Lun off set,Can i tell scan only 1-10 LUNs or 11-20.So that it will scan only those?

xe2sdc · Answer

Lun offsett is a feature offered by our storages .. Solaris can "see" only luns with lun id from 000 to 0ff (255 luns). But you can map more then 1000 devices on a FA port.

Have a look at the following thread:

https://forums.emc.com/forums/thread.jspa?messageID=500258񺈢

Enjoy!

srichev · Answer

Thanks..I will be setting up test environment to filter devices.Message was edited by: srichev

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