Well, I try to fin some issues in the log files, I read some of them : critical, error, syslog, etc... without success.
I don't know what I'm looking for.

For this server, I use DSS V6.0up75.8401.5377 64bit Lite release.
2 Intel Corporation 82571EB Gigabit Ethernet Controller (rev 06) and 2 Intel Corporation 82574L Gigabit Network Connection as ISCSI Target in different sub LANs.
Jumbo frame is activate in all chain.
1 3Ware controler with HDD SAS 15k in Raid6 mode for one array of 1.6 To, 500 Go in used for 10 VM.

Let me know if I need further information.