RAID

[all star]

Hi,

I have a Pentium 4 Machine running with Redhat Advanced Server 2.1 running. Server has AIC 7901 SCSI controller Adapter. When i connect a External RAID box at 320Mbps Speed i observe the following error messages

(scsi0:A:2): 3.300MB/s transfers

> scsi0: Returning to Idle Loop

> (scsi0:A:2): 320.000MB/s transfers (160.000MHz DT|IU|QAS, 16bit)

> (scsi0:A:2): 3.300MB/s transfers

> scsi0: Returning to Idle Loop

> (scsi0:A:2): 320.000MB/s transfers (160.000MHz DT|IU|QAS, 16bit)

> (scsi0:A:2): 3.300MB/s transfers

> scsi0: Returning to Idle Loop

> (scsi0:A:2): 320.000MB/s transfers (160.000MHz DT|IU|QAS, 16bit)

> (scsi0:A:2): 3.300MB/s transfers

> scsi0: Returning to Idle Loop

> (scsi0:A:2): 320.000MB/s transfers (160.000MHz DT|IU|QAS, 16bit)

> (scsi0:A:2): 3.300MB/s transfers

> scsi0: Returning to Idle Loop

> (scsi0:A:2): 320.000MB/s transfers (160.000MHz DT|IU|QAS, 16bit)

> (scsi0:A:2): 3.300MB/s transfers

> scsi0: Returning to Idle Loop

> .

When i reduce the Speed to 160Mbps everything works fine.

what could be the problem. Upgrading the driver would be last option for me.
Thanks in Advance

regards
chakri

[Steven E. Protter]

Shalom,

You fail to state what kind of external raid arrray it is.

It may be incompatible with the SCSI card.

In that case upgrading the driver or OS will be useless because the combination won't work.

Check the documentation on the disk array and see if this SCSI card is certified.

Does the array work at slower speeds?

SEP

[all star]

Thanks for the response.

Adaptec BIOS is detecting the raid at 320Mbps raid. Operating system detects but gives above error message. If i disable Multi LUN support then it works fine.
As per the vendor RAID is compatible with the SCSI host controller i'm using.

regards
chakri

[Sachin Patel]

What type of disks are you using. if they are slower speed then this could happen.