AIX5L and EMC SAN disks

[oliverbeat]

Hi,

I never never used EMC/SAN disks on AIX servers. I always used ESS/SAN. So it is completly new, I need some helps ...
First: what do we need to install on the AIX system to see the EMC disks (for ESS/SAN: I installed sdd driver)
When we see the EMC disks (after cfgmgr), should I use some specifics commands to see the status etc ... (for ESS/SAN: used the command dataph query ...).

Thank you a lot in advance.
If you have some doc or links ...

 

[plamb]

you will need to remove the SDD code install the EMC Symmetric ODM drivers and install POwerPath. "inq" will show the individual EMC hdisks and the hdiskpower sizes. The command "powermt display" with variour options will show the pathes.

 

[p5wizard]

I should think it is not necessary to remove SDD? Can't different multi-pathing drivers live side by side? It would be handy when migrating from one storage server brand to another?



HTH,

p5wizard

 

[hfaix]

I agree with p5wizard, however, I've never tried this. I find it hard to believe a system can only be tied to one type of disk subsystem.

 

[p5wizard]

What I've been told is that SDD recognizes the ESS/DS type LUNs and vpaths only those. Other drivers should act along the same lines... However also never tried it yet.

But this I do know: AIX MPIO and plain-vanilla SDD don't agree with each other -- if you install SDD, MPIO is removed. But there is an MPIO PCM that allows MPIO and SDD to work together.

(PCM=PathControlModule)


HTH,

p5wizard

 

[plamb]

EMC books say remove SDD

 

[p5wizard]

Just read on EMC website why. It's because PowerPath also supports multipathing to non-EMC boxes, including ESS.

So yes - remove SDD before installing PowerPath - and if migration is necessary: use PowerPath to migrate data from ESS to EMC.

You'd need to exportvg when connected to ESS via SDD, then remove all vpaths and their hdisks, reconnect to ESS via PowerPath, discover ESS hdiskpower devices and importvg. Assign EMC LUNs and discover EMC hdiskpower disks. Then extendvg with EMC hdiskpower disks and migratepv to the new disks. I presume such operations are described in more detail in the EMC books?


HTH,

p5wizard

 

[CrystalWizard]

you can't run sdd and powerpath together on the same machine.

well...let's put it this way. you MIGHT, if you write your own code, get it to work. But you will not get support for it from either EMC or IBM. you have to install one or the other, not both. That means uninstalling SDD if you're going to run powerpath or powerpath if you're gonna run SDD.
That means you can NOT put 2105 disks and emc disks on the same server.

 

[p5wizard]

this is quoted from EMC website:

EMC FullTime PowerPath combines multiple path I/O capabilities, automatic load balancing and path failover functions into one integrated package—for use on open server platforms connected to EMC Symmetrix, EMC CLARiiON, Hitachi Data Systems (HDS) Lightning, HP XP (Hitachi OEM), IBM Enterprise Storage Server (Shark) and HPQ storage systems.

EMC allows other SAN vendor's LUNs to be multipathed and path-failovered - I presume to ease customers' migration efforts after a win-back situation.


HTH,

p5wizard

 

[DSMARWAY]

hi ,

Is this a new install i.e. do you have data / applications running on this server and want to move to EMC ?


if so see below otherwise see new install, make sure you have good backups

umount all filesytems that use the old disk
make a note of pvids of current disks
export volume groups preferred / varyoff the volume groups
remove the disk(e.g lsdev –C | grep MPIO ) associated with the old disk storage. ( rmdev -dl .. )
then install the powerpath software ( check install notes depending on what version you are installing you may need to install a lower version first )

reboot server

lsdev -Ccdisk

disks you'll see are:-
you'll see hdiskpower? disks and hdisk25 and hdisk26 showing as none ( these are the alternate paths to the disks)

you use hdiskpower? disks when extending filesystems don't use hdisk25 hdisk26

powermt display dev=all ( will show you all the disks and alternate paths)

Note :- check pvids of disks taken previously they should match the hdiskpower pvids , your data should be intact
if exported import volume with hdiskpower disk but with correct pvid


New install
==========
1. Makes sure all cables to switches to cards to EMC are physically connected

2. Make sure your fibre adapters / your cards connected to the EMC are physically connected and the cards setup correctly i.e. the fibre cards ( from memory i think should be setup as arbitrated loop)

3. Then install the power path software

4. To check if you can see the disks
run
powermt display dev=all
( if you get nothing found) then you have a problem with the connectivity or the EMC guys haven't assigned the disks to your server .
if yu get loads of info lisiting hdiskpower disks then your
in business
create volume groups add the hdiskpower disks in volume groups and create LVs on the hdiskpower disks

( You'll have to tell the EMC guys how big you want the EMC Luns )

HTH