A strange problem on SATA HD

[raid]

Scenario:
Proxmox 1.5 upgraded to 1.6 on september 2010 (Kernel 2.6.32 with OpenVZ)
CPU Intel I7 4x2Ghz + 4 GB RAM on Asus MB
2 HD 500MB in Raid HW (mirroring)
1HD 1Tb ext3 on SATA (VM backup)
1 OpenVZ Virtual Machine (Ubuntu) with a Backup subdirectory bind mounted on the 1TB HD (database backup)
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Everything was fine until yesterday night when the backup failed because 1TB HD was not accessible.
After a server restart (from proxmox panel) the HD disappeared.
The server farm technicians checked and tested the HD on another server without encountering any problems, the HD worked perfectly.
Later they reconnected the disk to my server and after the boot it worked again like nothing had happened.
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Any ideas?
thanks
p.s.: the technicians in the server farm, who don't know proxmox and maybe don't like it too much, suggest a kernel problem.

 

[oeginc]

Did you check the drive with smartmontools to see if there were any S.M.A.R.T. hiccups? Did you have any warning messages in your kernel log?

 

[raid]

- fdisk -l didn't see the HD
- the HD was seen by bios correctly
- putting the disk on usb case was seen by bios and system
- Once HD was shifted from SATA1 to SATA0 the problem was solved.

- for lack of time we have not performed the countercheck on SATA1
- No errors on the Kernel log