MegaRAID (MR) SAS Adapter FW is exposing VDs (Logical Disks) with WCE enabled in Mode Sense command for drives that are configured as WriteBack by the user. When the VDs are exported as Write Back drives, OS is sending "Synchronize Cache" command to the drives frequently. Per SCSI Spec, this command is an optional command and MR firmware is rejecting this command as unsupported. User is advised to enable "Write back" only when battery is available (in Adapter) The FW does flush cache periodically. Looks like OS do not like rejecting the command on a boot volume and so adding the following event message to the event log each time the call is failed. These messages are flooded by OS and is causing annoyance to the user. Message from the log : Jan 12 17:58:06 linux kernel: FAILED Jan 12 17:58:07 linux kernel: status = 1, message = 00, host = 0, driver = 08 Jan 12 17:58:07 linux kernel: <6>sd: Current: sense key: Illegal Request Jan 12 17:58:07 linux kernel: Additional sense: Invalid command operation code 1. Shouldn't the OS stop sending the sync cache cmd if it sees it is "Failed" with "Invalid Command" in sense info ? 2. Is there a way by which LLD can stop the OS from sending the SYNC cmd down? Thanks, Sumant - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
