File transfer speed

[dirkdevos]

Hi,

We have just purchased a C7000 enclosure and a BL860c i4 blade and we are not sure what is causing our transfer speed issue. When we use scp to copy data between VMs or between the host and a VM we are seeing transfer speeds ranging from 5MB to 30MB per second. As we are in the process of getting the systems up and running there is barely any load on the servers.What first drew our attention to this was when we tried to restore data from a LTO tape drive that is connected to a Proliant server running Windows 2012.

With 2 VMs defined with 6 CPUs and 60GB of memory we maxed out at 30MB/s and transfering a large file between 2 blades maxed out at 50MB/s. What we also noticed that when transfering huge amounts of data we slowed down to around 1MB/s.

My first question is what range of transfer speed should we expect with 10Gb NICs on the blade? Secondly, If our transfer rates are below what they should be, are we looking at an isssue with the enclosure, inter connects or the blades themselves.

Any ideas would be greatly appreciated.

[Steven Schweda]

   I know nothing about blades in general, your configuration in
particular, and virtual machines, but ...

> [...] we use scp to copy data between VMs or between the host [...]

   "data"?  Are you talking about files on disks?  Disks connected how,
to what, exactly?  Actual command(s)?

> [...] transfering a large file between 2 blades [...]

   Blades connected how, to what, exactly?

   I would say that you're transferring a large file from one disk to
another disk, rather than " between 2 blades".  As I understand the
situation (from your vague description), first, you need to read
the file data from one disk into memory on one blade.  Then you need
to send the data to another blade, and write them to some other(?) disk
from there.  Knowing nothing about who's connected to whom, how, I'd
worry about each of these steps, especially the disk I/O, before
worrying too much about the network hardware.

   If I were looking for maximum speed, and the data weren't leaving the
room, then I might try not to incur the extra overhead of the "s" in
"scp".

> [...] we tried to restore data from a LTO tape drive that is connected
> to a Proliant server running Windows 2012.

   What's the software on the blades?  How is that Windows system
connected to the blades?

> Any ideas would be greatly appreciated.

   You might start with a more detailed description of your software and
hardware, including the storage and network interconnections.  (My
apologies if "C7000" really tells all, and I'm too ignorant to see
that.)  Then I'd try looking at the simpler sub-operations which are
hiding in that "copy" operation, to try to see where the bottleneck
lies.

[dirkdevos]

Just to clarify, I am not looking for an exact transfer speed but a general indication of what a person could/should expect. The data is not leaving the room.

All the networking gear is capable of 10Gb. We have a HP 3PAR storage system connected to 2 san switches. The san switches are connected to the HP C7000 enclosure's interconnect fiber ports. The interconnect connect to the backplane of the enclosure. Each blade connects to the backplane via the 4 onboard NICs. The hosts and vm's are all running HP-UX 11.31 with the latest patches applied. The hosts have 140GB SAS drives and the vm's are running on LUNs defined on the 3PAR. The Windows server has a 1Gb NIC and the LTO tape drive is connected to the server via a SAS interface card. The tape drive is capable of a sustained transfer speed of 140MB which is just over 1Gb. The data that I am refering to is just a large data file.

So from the LTO drive to a vm we are going through a SAS interface at 140MB/s to a Windows server with a 1Gb/s NIC which is connected to a 10Gb/s switch. The switch connects to the enclosure's interconnect at 10Gb/s and then from the vm to the 3PAR over fiber. Between the 2 HP-UX vm's all the traffic is on the enclosure's backplane or over fiber to the 3PAR.

[Torsten.]

I'm still not sure about what you have.

A c7000 enclosure with a single BL860c i4 running HP-UX 11.31 with virtual machines.

What interconnect modules exactly?