MD3000i Virtual Disk not on preferred path

Question

Hi all,   I have two PE R710 ESXi 4.0 hosts connecting to an MD3000i.  It has two arrays - one with a total capacity of 817 GB using SAS drives, and one array with 2 TB using SATA drives.  Each array is using a different controller and is configured as the owner/preferred path respectively.  We're using VMWare Essentials, which gives us a little less management capability.  vSphere indicates that everything is healthy and running fine; however, when I open the Dell Modular Disk Storage Manager, I notice every 10-15 minutes or so the Storage Array indicator blinks red indicating that it failed over to a non-preferred path.  As soon as it fails, it almost immediately switches back to the optimal/preferred path.   I'm not quite sure if this is something I should worry about because we haven't had any problems with any of our virtual servers.  This has been a sporadic issue for the past 3-4 months.   Below is a sample of the error logs I've been receiving in chronological order. Date/Time: 10/6/10 10:42:22 AMSequence number: 1769975Event type: 4011Event category: ErrorPriority: CriticalDescription: Virtual Disk not on preferred path due to AVT/RDAC failoverEvent specific codes: 0/0/0Component type: RAID Controller ModuleComponent location: RAID Controller Module in slot 0Logged by: RAID Controller Module in slot 0 Raw data:4d 45 4c 48 03 00 00 00 f7 01 1b 00 00 00 00 00 11 40 18 01 de 98 ac 4c 00 00 00 00 00 00 00 00 00 00 00 00 01 00 00 00 08 00 00 00 08 00 00 00 ff ff ff ff 00 00 00 00 4c 10 8f 03 90 0b 32 00 7c 14 02 0c 30 00 00 00 b0 bc 34 00 00 00 00 00 7c 14 02 0c 08 5f 35 00 bc 27 1c 00 ee ee ee ee ee ee ee ee 00 00 00 00 5c 0f 8f 03 cc 2e 05 00 01 00 00 00 00 00 00 00 00 00 00 00 Date/Time: 10/6/10 10:37:22 AMSequence number: 1769959Event type: 4011Event category: ErrorPriority: CriticalDescription: Virtual Disk not on preferred path due to AVT/RDAC failoverEvent specific codes: 0/0/0Component type: RAID Controller ModuleComponent location: RAID Controller Module in slot 0Logged by: RAID Controller Module in slot 0 Raw data:4d 45 4c 48 03 00 00 00 e7 01 1b 00 00 00 00 00 11 40 18 01 b2 97 ac 4c 00 00 00 00 00 00 00 00 00 00 00 00 01 00 00 00 08 00 00 00 08 00 00 00 ff ff ff ff 00 00 00 00 4c 10 8f 03 90 0b 32 00 7c 14 02 0c 30 00 00 00 b0 bc 34 00 00 00 00 00 7c 14 02 0c 08 5f 35 00 bc 27 1c 00 ee ee ee ee ee ee ee ee 00 00 00 00 5c 0f 8f 03 cc 2e 05 00 01 00 00 00 00 00 00 00 00 00 00 00 Date/Time: 10/6/10 10:32:22 AMSequence number: 1769942Event type: 4011Event category: ErrorPriority: CriticalDescription: Virtual Disk not on preferred path due to AVT/RDAC failoverEvent specific codes: 0/0/0Component type: RAID Controller ModuleComponent location: RAID Controller Module in slot 0Logged by: RAID Controller Module in slot 0 Raw data:4d 45 4c 48 03 00 00 00 d6 01 1b 00 00 00 00 00 11 40 18 01 86 96 ac 4c 00 00 00 00 00 00 00 00 00 00 00 00 01 00 00 00 08 00 00 00 08 00 00 00 ff ff ff ff 00 00 00 00 4c 10 8f 03 90 0b 32 00 7c 14 02 0c 30 00 00 00 b0 bc 34 00 00 00 00 00 7c 14 02 0c 08 5f 35 00 bc 27 1c 00 ee ee ee ee ee ee ee ee 00 00 00 00 5c 0f 8f 03 cc 2e 05 00 01 00 00 00 00 00 00 00 00 00 00 00 Date/Time: 10/6/10 10:22:48 AMSequence number: 1769920Event type: 4011Event category: ErrorPriority: CriticalDescription: Virtual Disk not on preferred path due to AVT/RDAC failoverEvent specific codes: 0/0/0Component type: RAID Controller ModuleComponent location: RAID Controller Module in slot 1Logged by: RAID Controller Module in slot 1 Raw data:4d 45 4c 48 03 00 00 00 c0 01 1b 00 00 00 00 00 11 40 18 01 48 94 ac 4c 00 00 00 00 00 00 00 00 00 00 00 00 01 00 00 00 08 00 00 00 08 00 00 00 ff ff ff ff 01 00 00 00 80 8c 8f 03 90 0b 32 00 b0 12 02 0c 30 00 00 00 b0 bc 34 00 00 00 00 00 b0 12 02 0c 08 5f 35 00 bc 27 1c 00 ee ee ee ee ee ee ee ee 00 00 00 00 90 8b 8f 03 cc 2e 05 00 01 00 00 00 00 00 01 00 00 00 00 00 Date/Time: 10/6/10 10:02:23 AMSequence number: 1769822Event type: 4011Event category: ErrorPriority: CriticalDescription: Virtual Disk not on preferred path due to AVT/RDAC failoverEvent specific codes: 0/0/0Component type: RAID Controller ModuleComponent location: RAID Controller Module in slot 0Logged by: RAID Controller Module in slot 0 Raw data:4d 45 4c 48 03 00 00 00 5e 01 1b 00 00 00 00 00 11 40 18 01 7f 8f ac 4c 00 00 00 00 00 00 00 00 00 00 00 00 01 00 00 00 08 00 00 00 08 00 00 00 ff ff ff ff 00 00 00 00 4c 10 8f 03 90 0b 32 00 7c 14 02 0c 30 00 00 00 b0 bc 34 00 00 00 00 00 7c 14 02 0c 08 5f 35 00 bc 27 1c 00 ee ee ee ee ee ee ee ee 00 00 00 00 5c 0f 8f 03 cc 2e 05 00 01 00 00 00 00 00 00 00 00 00 00 00 Date/Time: 10/6/10 9:42:22 AMSequence number: 1769731Event type: 4011Event category: ErrorPriority: CriticalDescription: Virtual Disk not on preferred path due to AVT/RDAC failoverEvent specific codes: 0/0/0Component type: RAID Controller ModuleComponent location: RAID Controller Module in slot 0Logged by: RAID Controller Module in slot 0 Raw data:4d 45 4c 48 03 00 00 00 03 01 1b 00 00 00 00 00 11 40 18 01 ce 8a ac 4c 00 00 00 00 00 00 00 00 00 00 00 00 01 00 00 00 08 00 00 00 08 00 00 00 ff ff ff ff 00 00 00 00 4c 10 8f 03 90 0b 32 00 7c 14 02 0c 30 00 00 00 b0 bc 34 00 00 00 00 00 7c 14 02 0c 08 5f 35 00 bc 27 1c 00 ee ee ee ee ee ee ee ee 00 00 00 00 5c 0f 8f 03 cc 2e 05 00 01 00 00 00 00 00 00 00 00 00 00 00 Date/Time: 10/6/10 9:27:48 AMSequence number: 1769689Event type: 4011Event category: ErrorPriority: CriticalDescription: Virtual Disk not on preferred path due to AVT/RDAC failoverEvent specific codes: 0/0/0Component type: RAID Controller ModuleComponent location: RAID Controller Module in slot 1Logged by: RAID Controller Module in slot 1 Raw data:4d 45 4c 48 03 00 00 00 d9 00 1b 00 00 00 00 00 11 40 18 01 64 87 ac 4c 00 00 00 00 00 00 00 00 00 00 00 00 01 00 00 00 08 00 00 00 08 00 00 00 ff ff ff ff 01 00 00 00 80 8c 8f 03 90 0b 32 00 b0 12 02 0c 30 00 00 00 b0 bc 34 00 00 00 00 00 b0 12 02 0c 08 5f 35 00 bc 27 1c 00 ee ee ee ee ee ee ee ee 00 00 00 00 90 8b 8f 03 cc 2e 05 00 01 00 00 00 00 00 01 00 00 00 00 00 Date/Time: 10/6/10 9:27:22 AMSequence number: 1769680Event type: 4011Event category: ErrorPriority: CriticalDescription: Virtual Disk not on preferred path due to AVT/RDAC failoverEvent specific codes: 0/0/0Component type: RAID Controller ModuleComponent location: RAID Controller Module in slot 0Logged by: RAID Controller Module in slot 0 Raw data:4d 45 4c 48 03 00 00 00 d0 00 1b 00 00 00 00 00 11 40 18 01 4a 87 ac 4c 00 00 00 00 00 00 00 00 00 00 00 00 01 00 00 00 08 00 00 00 08 00 00 00 ff ff ff ff 00 00 00 00 4c 10 8f 03 90 0b 32 00 7c 14 02 0c 30 00 00 00 b0 bc 34 00 00 00 00 00 7c 14 02 0c 08 5f 35 00 bc 27 1c 00 ee ee ee ee ee ee ee ee 00 00 00 00 5c 0f 8f 03 cc 2e 05 00 01 00 00 00 00 00 00 00 00 00 00 00 If anyone has any insight as to what may be going on, I would appreciate it.  As this is a mission critical server, I really don't want to have to replace the controllers.   Thanks!

JOHNADCO · Answer

Dang where start?

So many things can cause this. Dell highly suggests 4.0 U2 or above. As ESXZ has had issues with this.

Most of the time it is a network configuration error. As in the VM / Host cannot communicate on the correct path / controller.

Are all you correct paths showing up on the iSCSI storagae adapter tab? Do all your net works show as up on the networking tab?

Both of those are under configuration in the VI Client.

JOHNADCO · Answer

PS:  As of the last FW update we have found if a given controller gets close to saturation it can happen as well.   Are you making any VD's?  Are you ding and VDC's?

mrokkam · Answer

Do you have iscsi sessions to both the controllers from each host system? -Mohan

PowerVault

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