What the books DON’T tell you about moving from one platform to another

Thanks Allen for the answers

If I would like to think about the VMAX & DMX configuration base on the host side application from the user perspective, would you please recommand any documentations for reference? Example, How to, etc.

Hey experts , I have another question:

suppose I have a Linux host with several disks and I'm migrating from CX to VNX or DMX to VMAX, or VMAX to CX... in fact it doesn't matter at all since my question is about the point where Linux finally sees the new LUNs I've presented and I made sure the data has been copied over from the source to the target LUN. Linux simply doesn't recognise the new LUNs as the old ones. For Linux it's like the old LUNs are gone and it received a bunch of new LUNs. Do you have any ideas about how to migrate data from an old storage system to a new system without loosing data ? Ok, host based mirroring is an option that seems fool proof, but I'd like options that don't include the hosts itself.

Depending on what exactly you are looking for here there are two series of whitepapers I would recommend.

For host connectivity in general there is a series of host connectivity guides targeted at various operating systems that go deep into the gory details of connectivity to various EMC storage platforms and all the details you need to consider.

If you are looking for more specific application configuration (and associated storage configuration) there is a series of whitepapers on specific applications (i.e. Microsoft Exchange, Oracle, etc) that dive deep into those topics.

You can find all those whitepapers on Powerlink.

This seems to be more of a host based issue since the way a host recognizes a LUN is driven by the OS itself. I no longer do a lot of in depth work on the OS side of things... I work WITH the Server specialists, but I rely mostly on their specialization. Maybe dynamox will have more insight on this one since I believe he still does a fair bit of host based work too (and we all know he just lovesLinux *lol*)

dang, i did not setup notification for "meet the expert", I'll jump on it tonight.

zj wrote: Hello So far, I knew about moving data from one platform to another is we can use OR to do it. Will you please make a brief discription about the difference among OR OM and SRDF in data moving?

OR (Open Replicator)  is a great tools that can move data to and from Symmetrix/VMAX,  most shops use it for migration purposes only but it could also be used to perform occasional data copies between two frames.

OM (Open Migrator) - is a host based tool,  some of its functionality has been augmented by PowerPath Migration Enabler (PPME ) but what sets OM apart from PPME is it's storage agnostic, it also migrates at partition level, not at the disk level so you can migrate from larger device to a smaller device as long as the partition fits on the target.

SRDF - Allen covered that already, it's your "Cadillac" when it comes to data replication (Symmetrix platform only).

RRR wrote: Hey experts , I have another question: suppose I have a Linux host with several disks and I'm migrating from CX to VNX or DMX to VMAX, or VMAX to CX... in fact it doesn't matter at all since my question is about the point where Linux finally sees the new LUNs I've presented and I made sure the data has been copied over from the source to the target LUN. Linux simply doesn't recognise the new LUNs as the old ones. For Linux it's like the old LUNs are gone and it received a bunch of new LUNs. Do you have any ideas about how to migrate data from an old storage system to a new system without loosing data ? Ok, host based mirroring is an option that seems fool proof, but I'd like options that don't include the hosts itself.

you are correct, whenever you utilize array based migration tools, at some point you will need to present the new LUNs to the host. For example if you were migrating from CX to VNX using SanCopy, at some point of your migration you will need to shutdown the host, run final SanCopy session (incremental), unzone CX and present VNX. You will see that Linux will not re-use the same /dev/sdX devices, it will create an entire new set of devices (that's been my experience). It's not an issue for Linux, if these devices were used as part of LVM (logical volume manager), Linux will recognize the volume group id (vgid) and will be able to re-import the volume group. Some people will notice that PowerPath device names (emcpowerX) will change for new devices, since LVM uses vgid it will still recognize and re-import the volume group.  What is your experience RRR ?

I'm not a Linux guy myself, unfortunately , but I had a discussion with one of our Linux guys and he was sort of complaining that Linux didn't recognise the replicas and he had to rename the power devices manually. I'm not sure why he would need to do that, but I was hoping for a way that when the old LUNs have replicated to the new LUNs these new ones would be automatically recognised as the old LUNs.

sloppy, very sloppy

Back to 2008/2009, I was tring to talk everyone in I know in EMC about SAS.

Once I got a chance to ask the director of USD about EMC's plan/strategies of SAS, but when I rasied my hand, session was announced time out.

Hi all, this discussion is now closed. However Allen will be wrapping this discussion up with a video from EMC World 2012 in Las Vegas. He will talk about the highlights of this discussion as well as the key learning points. We will also as Allen to answer any questions that came in at the end of the discussions time. Watch this space.

Video Link : 3217

Attached here is the wrap up Dynamox and Allen gave about this discussion at EMC World. Hear what they have to say regarding the highlights of this discussion