Moving Data to ESS from AutoRaid

[Justin Willoughby]

We are planning to move data from our Model 12 AutoRaids to an IBM ESS Shark connected via fibre.

The question is, how is the best way to move the data. The two ways I was thinking about doing it (while the system is up and being used):

pvmove or
Mirror to the ESS and break the mirror

Which one is better? I was just thinking of doing a pvmove but I would like to know what everyone else thinks.

Also, we were told by another company that hooked up their HP to an ESS that if you use IBM???s software/driver to utilize the bandwidth of both fibre cards that you risk crupting the data on the ESS if you end up restoring VG00 from an Ignite backup tape. Has any one heard this? The other option is to not use IBM???s software and the second fibre card is just a hot fail-over and used for data transfer.

[Justin Willoughby]

Oh, BTW, the HP box I am talking about hooking up to the ESS is a K570. The fibre cards we are planning to use are A6685A (HSC Tachlite Fibre Channel Adapter).

- Justin

[Holger Knoppik]

Hi Justin,

1.) I would feel better by using the mirror. The education stuff for LVM says be aware of fragmentation (degrading performance). And i would miss my MirrorDisk/UX ,of course ;-)

2.) I think you mean the subsystem device driver. I just heared about utilizing the bandwith, nothing about any risks. Anyway, we use the pvlink feature for redundancy. At a certain level of traffic, our cards (A5158A) start load balancing.
For information about the SDD, check this out:http://ssddom01.storage.ibm.com/techsup/swtechsup.nsf/support/sddupdates
Hope this helps a bit
RGDS, Holger

[Justin Willoughby]

We may just use pvlinks and stay away from IBM's SDD unless bandwidth ends up being a major problem or we can be assured Ignite can restore VG00 without effecting volume groups located on the ESS.

I got the following from another hospital. They are using the SDD from IBM, even with the risk of possible problems with doing a Ignite restore. I have not see anything written about this, only heard about it via a conference call with this other hospital. The following is what I was forwarded from another hospital who I would assume talked to IBM about this:


Here is what IBM said about it:

The reason Ignite is complaining about vpaths is that it does not know how to handle pseudo devices. Unfortunately there isn't much we can do here as SDD's design as a pseudo device driver is fundamental to what it does. As SDD is not responsible for managing the 1:1 relationship between a logical device and that device's hardware path but creates pseudo devices (vpaths) to distribute calls across multiple aggregated disk logical devices, its function dictates that it must be a pseudo device. And, Ignite doesn't like pseudo devices.

There is a way to get around this issue. Before running Ignite used vgextend and vgreduce to move the volume group from vpaths to pvlinks. Then run Ignite and, upon completion, move the volume group back to vpaths. In this scenario, Ignite would never need to interact with the vpath and, thus, would not complain.

[Justin Willoughby]

Also Holger, What HP9000 server are you using with your ESS? Are you going though a fibre switch? How is it confiugred Arbitrated Loop or Fabric Login?

Thanks!

- Justin

[Holger Knoppik]

Hi again, Justin,

when i read this, i'm glad not using the SDD! But it's good to know having a workaround for that situation. The szenario connecting an ESS to a HP9000 server is a bit more complex than having all stuff from the same company (i think you know what i'm talking about ;-).Our 4 L-Classes (9000/800/L2000-44, each with 2 FC cards) are connected redundant over 2 fabric switches to 2 sharks.
The Topology output from fcmsutil shows PTTOPT_FABRIC.
HTH,
RGDS, Holger

[Holger Knoppik]

Justin ???
Any progress ??

N/A for this post ...

RGDS, Holger

[Justin Willoughby]

Holger,

As for the SDD, I think I am not going to install it (the SDD from IBM). Instead I am going to alternate which LUNs from the ESS are the primary and which is the secondary between the two fibre cards so both cards will be used.

We have not ordered the fibre cards yet. We are waiting for one of our vendors to get back with us on what other hardware upgrades we need (CPU & Memory) so we can bid out all of the hardware together.

Not sure if this is what you were looking for.

Thanks for your reply!

- Justin

[Justin Willoughby]

BTW, the other hardware upgrades are not related/needed for the fibre cards but because we are going to be adding more users to the applications running on the box.

[Justin Willoughby]

I have a quick follow up question.

Should I install the driver for the A6685A (HSC Tachlite Fibre Channel Adapter) before I have HP install the actual card?

- Justin