Problems with backing up to HP 3par disks

Hi,

We have a SQL2012 SP1 build 3412 availability group cluster that recently moved the backend SAN to HP 3par. Since the move we have had the disk array setting changed to high performance for 3par but we still get the errors

The operating system returned the error '59(An unexpected network error occurred.)' while attempting 'SetEndOfFile' and

The operating system returned the error '59(An unexpected network error occurred.)' while attempting 'FlushFileBuffers'.

I have seen http://dirkhondong.wordpress.com/2012/01/27/the-specified-network-name-is-no-longer-available-sql-backup-problem-solved/ as we are using Ola's backup solution. Is changing the registry by creating a DWORD with name ‘Sesstimeout’ and value 360 in HKLM\SYSTEM\CurrentControlSet\Services\lanmanworkstation\parameters the right approach?

Anybody else using HP 3par and having backup troubles?

Thanks

Chris