Disk Arrays
cancel
Showing results for 
Search instead for 
Did you mean: 

Disk file copy study; questions on performance ..

Stuart Abramson_2
Honored Contributor

Disk file copy study; questions on performance ..

Here's an interesting thing I noticed today timing disk filesystem copies on HP-UX servers (a2, a3, a5, w6, etc are UNIX servers):

Fm...NIC...FA.......To:...NIC...FA:.......FS....SZ...Time...Speed
--...---...------...--...----...------...-----..---...---...--------
w6...GigE..4a/13a...w8...GigE...4a/13a.../u413..7.6...24m...19.GB/hr
w7...---....4a/13a...w7...---.....4a/13a.../u501..3.4...15m...13.GB/hr
a3...100...3a/14a...w7...1000...4a/13a.../u78...3.2....8m...24.GB/hr
a2...100...4a/13a...w7...1000...4a/13a.../u31...3.9...15m...16.GB/hr
a5...100...3a/14a...w7...1000...4a/13a.../u31...3.9....8m...29.GB/hr
a5...100...3a/14a...w7...1000...4a/13a.../u31...7.6...12m...38.GB/hr*

The fastest copy I get is across the slowest LAN where the FA port connections are different.

The slowest copy I get is on the VERY SAME SERVER. No LAN involvement at all. But I'm copying from the same FAs to the same FAs. (And the same HBAs to the same HBAs.) I was kind of hoping that the PowerPath would take care of this.

It appears that the HBAs and FAs are the limiting factor here, not the LAN, or the disks.

What do you think? Has anyone done a study of transfer rates on filesystem copies?