Do you have any updates of your problem?
I have a similar problem with HP 3PAR and HP Proliant 460 G7/G8:
2015-02-05T10:32:14.430Z cpu11:98640)lpfc: lpfc_scsi_cmd_iocb_cmpl:2185: 0:(0):3271: FCP cmd x2a failed <5/2> sid x080c30, did x060600, oxid xba iotag x457 Time Out Returning Host Busy
2015-02-05T10:32:14.430Z cpu10:33578)NMP: nmp_ThrottleLogForDevice:2322: Cmd 0x2a (0x412e403dd540, 272365) to dev "naa.60002ac000000000000000040000561e" on path "vmhba0:C0:T5:L2" Failed: H:0x2 D:0x0 P:0x0 Possible sense data: 0x0 0x0 0x0. Act:EVAL
2015-02-05T10:32:14.430Z cpu10:33578)WARNING: NMP: nmp_DeviceRequestFastDeviceProbe:237: NMP device "naa.60002ac000000000000000040000561e" state in doubt; requested fast path state update...
2015-02-05T10:32:14.430Z cpu10:33578)ScsiDeviceIO: 2325: Cmd(0x412e403dd540) 0x2a, CmdSN 0x800e0038 from world 272365 to dev "naa.60002ac000000000000000040000561e" failed H:0x2 D:0x0 P:0x0 Possible sense data: 0x0 0x0 0x0.
2015-02-05T10:32:14.432Z cpu11:98640)lpfc: lpfc_scsi_cmd_iocb_cmpl:2185: 0:(0):3271: FCP cmd x2a failed <5/2> sid x080c30, did x060600, oxid xbe iotag x45b Time Out Returning Host Busy
2015-02-05T10:32:14.432Z cpu10:33578)ScsiDeviceIO: 2325: Cmd(0x412e4042cb80) 0x2a, CmdSN 0x800e0017 from world 272365 to dev "naa.60002ac000000000000000040000561e" failed H:0x2 D:0x0 P:0x0 Possible sense data: 0x0 0x0 0x0.
2015-02-05T10:32:14.439Z cpu11:98640)lpfc: lpfc_scsi_cmd_iocb_cmpl:2185: 0:(0):3271: FCP cmd x2a failed <3/2> sid x080c30, did x060700, oxid xcc iotag x469 Time Out Returning Host Busy
2015-02-05T10:32:14.539Z cpu11:98640)lpfc: lpfc_scsi_cmd_iocb_cmpl:2185: 0:(0):3271: FCP cmd x2a failed <3/2> sid x080c30, did x060700, oxid x199 iotag x536 Time Out Returning Host Busy
in this time on the vm host iotop shows:
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sdb 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3.00 0.00 0.00 100.00
and we have freeze on the system.