Hi Chandra. We're currently testing 1024 LUNs across four paths with the older handler but will be doing the same with the new handler later this month. It sounds like I should move this up in the queue. Regards, Wayne. -----Original Message----- From: linux-scsi-owner@xxxxxxxxxxxxxxx [mailto:linux-scsi-owner@xxxxxxxxxxxxxxx] On Behalf Of Chandra Seetharaman Sent: Saturday, April 04, 2009 5:31 PM To: dm-devel; Linux SCSI Mailing list Cc: Moger, Babu Subject: SCSI Hardware Handler and slow failover with large number of LUNS Hello All, During testing with the latest SCSI DH Handler on a rdac storage, Babu found that the failover time with 100+ luns takes about 15 minutes, which is not good. We found that the problem is due to the fact that we serialize activate in dm on the work queue. We can solve the problem in rdac handler in 2 ways 1. batch up the activates (mode_selects) and send few of them. 2. Do mode selects in async mode. Just wondering if anybody had seen the same problem in other storages (EMC, HP and Alua). Please share your experiences, so we can come up with a solution that works for all hardware handlers. regards, chandra -- 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 -- 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