On Tue, Sep 13, 2011 at 07:18:53PM +0400, Ilya Chernykh wrote:
On Tuesday 13 September 2011 18:22:40 Greg KH wrote:
It is obviously incorrect, if to follow the Lanana specification, and any intuitive logic. Why this driver uses SCSI names for USB devices?
Because USB storage devices are really just SCSI devices, look at the USB storage spec for details if you are curious.
Wow. On my system all disks except the DVD drive are4 shown as with sd* name. Does it mean the SATA drive is also a SCSI drive? I also have an IDE drive attached via a parallel cable, is it also a SCSI drive? This becomes ridiculous.
Please realize that this changed about 5 years ago. It is nothing new at all for anyone, so complaining now seems very strange to me.
There are different backends that use different methods. Currently KDE3 has two backends: a HAL backend that uses HAL api, and mtab/fstab backend that scans mtab table. HAL backend will be useless in a system without hal.
Also note that mtab/fstab backend is the most universal because any system no and in the future will have there tables, regardless whether it has udisks or other more complicated components.
But it sounds like the mtab/fstab backend is buggy. Please fix it :)
It is impossible to determine whether a given drive an USB drive or hard based on mtab only if the both use similar sd* name.
That is correct, which is why you should never use mtab for that as that is not what will correctly identify these types of devices. You are trying to have this interface do something it does not, and then complain when it is not correct. Shouldn't you consider that perhaps you should use something else instead to detect this?
Thus the mtab backend thinks about USB drives as of hard disks.
Lots of them are hard disks :)
Still this is incorrect, there in a "removable" device type that should be used. When using hal, the usb drives are shown with "flash drive" icon.
That's wrong then, fix HAL :)
This is completely correct. I insert a flash drive and see it as a flash drive.
Having a USB disk drive (really an ata->usb connector) show up as a flash drive seems like the incorrect thing to do, don't you think so?
It is actually interesting why USB devices are assigned SCSI-names, and should not they receive USB names.
No it isn't, it's been that way for over 10 years now, nothing new here at all
As I already said this contradicts at least the Lanana specification adopted in 2009. Even if this was the case for a long time, it obviously contradicts the modern specification.
Again, no, it does not, your USB device is really using the SCSI stack, so it is a SCSI device.
Do you have a prooflink?
Read the specification linked to at www.usb.org
Another question is that it seems that even SATA and parallel IDE devices also receive the SCSI-name.
Again, on purpose, has been this way for over 5 years now.
On which purpose and why this purpose is not reflected in specification?
Because your SATA device is using libata which is using the SCSI stack.
Having a consistant naming scheme for all block devices works out very well, and is not something that will be changed to go back to the old, broken days.
Do you call it "consistent" when USB and ATA drives which have nothing to do with SCSI are shown as SCSI?
It is "consistent" in that all storage devices are shown to the user through the same interface. And if you really want to detect the "type" of the device your block device is, then use the correct interface, not the incorrect one like you are trying to do. good luck, greg k-h -- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-factory+help@opensuse.org