Copying files > Snapshot > I/O Error

[ms-net]

Hi,

I am testing the DSS Testversion from CD.

I want to use DSS for VMware. Now I am a little surprised:

When i copy large files to a share on the DSS (e.g. a virtual Maschine) and create during the copy a snapshot, I get an error that my network share is not available. The file transfer is broken.

I think I cant run virtual maschines on DSS. Every time when a snapshot is taken, the virtual maschines would crash ?!?

Is this a fact, that I cant use a share during a snapshot is taken?

All the best, Markus

[ms-net]

Hi,

OK, it seems that a virtual machine is not able to run during a snapshot is taken.

I have tested with VMware Server over a CIFS Share. When I click the Snapshot-button in the Webinterface of DSS my Maschine crashed.

What can I do?

Greetings, Markus

[To-M]

Currently we are not certified with VMware with our NAS portion of DSS. Try using the iSCSI with Snapshot feature as we have not tested with the NAS of DSS. Please review future releases to see if any updates will provide proper usage with VMware and our NAS protion of DSS.

[ms-net]

Thank you for your very fast reply :-)

My English is not so good.

Did I understood your reply in that case that I can use VMware and Snapshots with iSCSI without a broken network connection during a snapshot is performing?

Thanks.

[To-M]

May you please try and get back with me. We have many VMware users working with our iSCSI products including DSS.

[ms-net]

Hi,

i Have tried ISCSI - it works fine :-)
Snapshots and copying large files during a snapshot are No Problem :-)
Thank you!

But I've poor performance.
With CIFS I have 9 MB/s on a 100 M/Bit Network.
With ISCSI I have only 2 MB/s on a 100 M/Bit Network with the same hardware.

What have i done wrong?

all the best, Markus

[To-M]

Actually CIFS and SMB (SAMBA) are slower then NFS or FTP for file protocols, so this would almost be ok for a 100MB NIC, best would be 12MB /s. For iSCSI this is slow - could mean something on the initiators end or the host system. Allot can cause poor performance, slow drives, CPU, RAM, switch.... please experiment as you should be higher higher then this by 4x. Try another system with 1GB NIC's on both.