Replying to two messages at once: > Date: Tue, 4 Nov 2014 11:14:39 -0500 (EST) > From: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> > cc: "Dale R. Worley" <worley@xxxxxxxxxxxx>, <linux-scsi@xxxxxxxxxxxxxxx>, > <linux-usb@xxxxxxxxxxxxxxx> > > On Tue, 4 Nov 2014, James Bottomley wrote: > > > On Mon, 2014-11-03 at 16:06 -0500, Dale R. Worley wrote: > > > Was there any resolution as to how large disk drives would be handled > > > if their interface did not support the "capacity" request that would > > > tell how large they were? > > > > Realistically no ... unless someone comes up with a reliable heuristic > > to give us the size. I can understand why the linux-scsi project would not want to take up what is really a hack to work around a hardware deficiency. > I posted a patch to allow the user to override the reported capacity: > > http://marc.info/?l=linux-scsi&m=140993840113445&w=2 > > Nobody responded to it. > > > > Unfortunately, such devices work OK with Windows (since Windows trusts > > > what the partition table says), you can't just say to the salesperson > > > "It has to work on drives over 3 TB." > > > > This is a stopgap: your 3TB drive can be guessed as the 16 bit capacity > > plus 2TB, but the same won't happen for a 5TB device. Believing the > > partition table gives us a chicken and egg problem because something > > still has to get the partition table on to the device. > > > > I don't think "don't buy something that doesn't work" is a hugely > > unreasonable response to this. > > The problem is knowing beforehand whether it will work. Once you buy > the device and can test it, returning it is annoying and time-consuming > at best. Or as I would phrase it, How do you turn "Don't buy something that doesn't work!" into an algorithm? That is: I'm standing in MicroCenter, holding a box in my hand that contains a USB-to-SCSI adapter. How do I determine whether or not it supports large disks? The problem being that it *works with Windows*, so I can't just ask the friendly salesperson, Does this work with 3 terabyte disks? In my case, the Diablotek device works, while the Kingwin EZ-Connect does not, despite being labeled in essentially the same way. (Neither says that Linux is supported.) I admit that my problem may be my deficiency in dealing with the retail situation, as I'm a much better software engineer than shopper. Dale -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
