topic Re: Implement host mirroring in HPE EVA Storage

Implement host mirroring

Bachur — Tue, 30 May 2006 00:40:40 GMT

Hi,

I have a setup of two EVA4k. These are connected to two nodes participating in a cluster via FC switch.

I want to mirror the entire data of one EVA4k into the other EVA4k. I do not want to implement Continuous Access Synchronous Replication due to some reasons.

Is there any reliable and best method to keep a mirror copy of the EVA4k data? I want to implement a host level mirroring or software miorring that can do this.

Regards,
Frank

Re: Implement host mirroring

m saravanan — Tue, 30 May 2006 01:01:27 GMT

Bachur,

The best way of doing is through HP Continuous access, which will keep the exact copy between the EVA.

For cost cutting, You can present the VDisks of same size from bothe EVA to both the hosts and to LVM mirroring.

Otherwise there is a Host based mirroring software from Synmantec. (I don't know the exact name of the software).

Cheers,
Saravanan

Re: Implement host mirroring

Kenan Erdey — Tue, 30 May 2006 01:13:53 GMT

hi;

if you present two evas to the same host, perhaps dd command may help you. but if the data to be transfered oracle data etc., you can use recovery tools like RMAN.

regards.

Re: Implement host mirroring

Bachur — Tue, 30 May 2006 02:30:41 GMT

Hi,

I have 20 LUNs on one EVA.
What are steps I should do in order to keep mirror copy all these LUNs into the other EVA4k.

Regards,
Bachur

Re: Implement host mirroring

Mario_66 — Tue, 30 May 2006 03:05:29 GMT

Hi,

Please, provide a little bit more information.

Hosts? OS?

M.

Re: Implement host mirroring

Bachur — Tue, 30 May 2006 04:44:01 GMT

Hi,

The disks which are present on one EVA4k will be hardware mirrored internally.
Now I need these many LUNs to be mirrored across the other EVA4k

I mean to say what are the steps required to carry out if I need to mirror all these LUN disks from one EVA to another EVA.

If I make all the Vdisks on one EVA4k appear to both the cluster nodes, can I use dd command on one of the cluster node to have a mirror copy of all the application data and database files in the 20 LUNs on one EVA to another EVA.

Please note that we are not implementing HP Continous access.

Regards,
Priotosh

Re: Implement host mirroring

raadek — Tue, 30 May 2006 04:58:22 GMT

Host based mirroring could be accomplished using HP OpenView Storage Mirroring Software (http://h18006.www1.hp.com/products/storage/software/sm/index.html)

It is re-badged DoubleTake product - very reliable & field-proven.

It offers some advantages over storage-based replication:
- it takes care about data consistency (e.g. for Exchange or SQL)
- you could couple this with MS Clustering & get automatic fail-over capability.

There are some disadvantages as well, e.g. it impacts host(s) performance.

Rgds.

Re: Implement host mirroring

Steven Clementi — Tue, 30 May 2006 07:26:50 GMT

HP Openview Storage Mirroring is a Windows only poroduct. From the looks of it, Bachur's cluster is NOT Windows based.

Bachur:

What IS the OS?

Veritas (symantec) offers Storage Foundations for UNIX which would probably be the best 3rd party option if you are interested in 3rd party software.

Otherwise manual "software" mirroring would work, or should work, but would not be very reliable and is less supported.

Steven

Re: Implement host mirroring

Bachur — Tue, 30 May 2006 07:51:50 GMT

Hi Steven,

My OS is HPUX on Itanium based servers.

Regards,
Bachur

Re: Implement host mirroring

Alzhy — Tue, 30 May 2006 09:54:19 GMT

Bachur,

Your best bet is to use VxVM (Veritas Volume Manager) mirroring. You will need to upgrade the base license to allow you to mirror. This is your best protection if you do not trust single array solutions like EVA arrays.

If you are currently running LVM, then it is an easy conversion process to VxVM .. after which the mirroring part is really easy. You can use the gui "vea" or command line.

You can also do this with LVM Mirroring but it actually has some limitations compared with VxVM...

Re: Implement host mirroring

Bachur — Wed, 31 May 2006 00:55:29 GMT

Hi Nelson,

When I do an swlist I can see that my system has Base VERITAS Volume Manager Bundle 4.1 f.

Do I still have to upgrade the base license?

I have 20 LUNs which are common to both the cluster nodes and I need to mirror the physical disks of one EVA4k to another so that in case of disaster of one of the EVA4k, the system would run from the other EVA4k.

In this case can I use VxVM to mirror all these disks?

Regards,
Bachur

Re: Implement host mirroring

Alzhy — Wed, 31 May 2006 07:44:05 GMT

Bachur - Yes you need to upgrade to Full VxVM - which is just purchsing the codeword to apply the license. You may also go the route of purchasing the license directly from Veritas (Symantec now). No upgrades/updates of VxVM software and OS is necesssary except for the occasional patches.