I am considering moving the Xenserver machines to a network location, removing them from the box in which the hypervisor is residing.

I have a gigabit network which theoretically can transport just over 100MB/s worth of data (about 125MB/s I think is the calculation) but I expect less then that in the real world.

A 100Mb network can do 12.5MB/s, but realistically, only about 9MB/s is capable after all the networking overhead is introduced, so assuming 90MB/s for a gigabit connection may not be unreasonable.

HD normally put out 40-60MB/s, so a gigabit network should not be a bottleneck (assuming only one connection).

Going to run some tests to see what throughput my LAN can sustain.

Running bonnie++ on /mnt/tower/disk1 I get

Version 1.03d       ------Sequential Output------ --Sequential Input- --Random-
                    -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
apps-server05 2072M 22582  11 23699   1 15228   0 53534  35 62733   1 165.6   0
                    ------Sequential Create------ --------Random Create--------
                    -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
              files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
                 16   832   2  1852   1  1079   1   812   1  2153   0   840   1

Locally on the workstation running Bonnie++ on the SSD drive with a 8gig file (4gigs ram in machine) I get:

Version 1.03d       ------Sequential Output------ --Sequential Input- --Random-
                    -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
workstation01 7416M 63910  62 49520  20 24627  11 96748  92 233131  38  2300   9
                    ------Sequential Create------ --------Random Create--------
                    -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
              files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
                 16 +++++ +++ +++++ +++ +++++ +++ +++++ +++ +++++ +++ +++++ +++

On the same workstation, using a 7200rpm 160 gig drive, I get:

To be done

I did some file copies with SCP (since it reports the transfer rate).
Between machines on the xen hypervisor with a local file I am getting about 75MB/s
Between same machines, with a file stored on the UnRAID server I am getting about 30MB/s in read speed. This is obviously limited by both the UnRAID machine or the network connection.

Did another SCP between my workstation machine and a virtual machine and I topped out at 9.9MB/s
Will have to investigate this further since I’m obviously only getting 100Mbit speeds, when I have a 1Gb connection? Maybe not…