Secure path

[David_492]

Dear all

i need to know about secure path methodology
Thank you all

[Kevin Harlan]

What is your question with regard to Secure Path? What it does? How it works? Something else?

[David_492]

Thank you kevin

Yes ,i mean what it does , How it works?

Thank you again

[Kevin Harlan]

I can answer a bit about what it does. How it works will have to be answered by someone more knowledgeable than me...

What this software does is manages multiple paths to the storage.

Basically, in order to have redundancy (i.e. for high availability), you have to have multiple HBAs and multiple paths to the same storage. That way, if an HBA fails, or a switch fails, or a fiber cable snaps, etc., then the server still has access to the storage.

The problem is, if you have multiple paths to the same storage, then the OS sees the exact same storage as different volumes/LUNs/whatever. Most OS filesystems are *not* cluster filesystems, and thus, cannot handle multiple accesses to the filesystem at the same time.

For example, if you presented the same NTFS filesystem simultaneously to two Windows 2000/2003 nodes, and they weren't clustered or members of the same cluster, both nodes can write to the filesystem at the same time -- and step on each other, and corrupt the filesystem.

The above is essentially what can happen if you present a LUN across multiple paths. The OS sees multiple filesystems, and thinks they are separate filesystems. Writes to drive E: and drive F: would really be simultaneous writes to the same filesystem at the same time, and would have the same problems.

What Secure Path does is manage these multiple presentations of the same LUNs. It makes it so that the OS sees only one copy of the LUN/filesystem at a time.

Secure Path also manages the pathways. It can detect failures on one path, and divert the I/Os down the another (working) path.

Does that help?

[Peter Mattei]

If you want to know more go to the SAN Design Reference Guide on http://h18006.www1.hp.com/products/storageworks/san/documentation.html
In Chapter 6, start reading on page 170.

Secure path Product info can be found here:
http://h18006.www1.hp.com/products/sanworks/secure-path/index.html

Cheers
Peter