EVA 5000 and replication products and performance

[Juan Francisco Esteve_1]

We'got two SAN's with Continuous Access replication on a production environment with Windows 2003 servers.

We think that performance problems may arise in the future when Production run in a "full" mode.

My questions are

1 What Storage products/Vendors supply any solution as a substitute of CA (Continuous Access), so they provide a better performance??

2. In the case that still using CA, what techniques/workarround can be taken to minimize proformance problems??

Thanks in advance.

[Ivan Ferreira]

The hardware based replication is the fastest method of data replication and CA is the only provided by HP for EVA. No software replication like Veritas should give you best performance.

For performance tips, see also:

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=1014894

[Juan Francisco Esteve_1]

Thanks for your quick answer.

At a first idea, it's clear that HW based solutions are faster than SW based solution if they do exactly the same.

But reviewing some IT Forums, someone recommended i.e. VxVM Mirroring and FlashSnap Technology

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=958707

because it just deal with changed blocks...

so any idea on how to substitute CA by SW solutions to better perfomance, no matter how it's done??

Thanks in advance

[Craig Howe_1]

Hi Juan

Have you looked at why you may have issues with CA before going down the software route? Examples could be:

Are you using SR2122-2 routers or the newer MPR with better network functionality?
What are your network settings? (Latency? Are you using scaling / jumbo frames? QoS on the replication link?) The network will dictate how well CA can perform.

Do you have set front end ports on the EVA for production and replication? (Requires zones for replication and other pr
Do you have EVAPerf setup to monitor the effects of a full copy and logging on the (source) SAN in testing mode?

Anyhow hope it helps

[Duncan Edmonstone]

Juan,

I think if you look at the points in the link you posted you will see that Nelson is suggesting VxVM and flshsnap as a replacement for *Business Copy* functionality, not Continuous Access.

You don't say a lot about your hardware setup - do you have full fibre between the arrays? Or is there an IP link in there as well?

HTH

Duncan

[dentistcorn]

Juan,

You have several options. Here goes:

1- FalconStor: hardware based block level copy.
2- Softek: Software based BLOCK level migration tool.
3- Brocade Tapestry line of products.

Good luck.

[Juan Francisco Esteve_1]

qvalor,

Thanks for your useful answer.

One question: for the case of FalconStor.

May I substitute just HP CA SW, and install/configure FalconStor Synchronous/Asynchronus Mirroring without change anything of the existing hardware (Appliances, etc.)???

In other words, the alternative I'm looking for is substitute HP CA by other storage/mirroring/replicate SW without change the hardware I've got (EVA5000, switches, etc...) and maintaining the same low level HP disk operations (diskgroups, LUN's, Virtual Disks).

Thanks for any help.

[Alzhy]

Juan,

Yes there are solutions out there and my favourite remains VxVM because of its close affinity with HP-UX (and commoncality with other Unices and Linux). As I've mentioned in my reponses to several posts in this distinguished forum - software based mirroring, replication and snapshot solutions can work in most situations. Best of all -- it frees you from hardware array vendor lock in. The idea of a software based mirroring/snashot solution may send shivers to some but you very well know that today's arrays are fast, today's SANs are even faster and there are alwyas excess CPU cycles.

I have not worked though with VxVM on Windows environments so I cannot attest to its validity as a viable solution. I am only speaking about my successful experience with departing from hardware based solutions. A classic example was when we were plagued with EVA5K problems and BusinessCopy issues. Since BC can only do snapshots on the same array - when a whole EVA5K goes down.. so do your clones and snapshots. Our only way out of the issue was via VxVM mirroring and Flashsnap. When a huge XP12K array moved in - we continued with the strategy and opted out of XP Business Copy -- so we are able to have snapshots accross different array architectures -- thereby increasing our storage stability. There are now plans to even locate a cheaper array (an existing EVA or a new lower cost array) to our DR center via Dark Fibre so "changed blocks" are fed through via the same software (VxVM) as we do now...