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#1
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Curious about Explorer view
Why does Explorer show external/portable disk drives as Hard Disks rather than Removable Storage? Seems to me they should be considered removable storage as that's what they actually are. |
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#2
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Curious about Explorer view
pjp wrote:
Why does Explorer show external/portable disk drives as Hard Disks rather than Removable Storage? Seems to me they should be considered removable storage as that's what they actually are. Perhaps because the USB presentation data (for the class type) sent from the device to identify itself to the OS is for disk instead of, say, optical media or flash media, or it identifies itself as an MSD (mass storage device) but a different subclass (command set). http://microchipdeveloper.com/usb:device-classes https://www.usb.org/defined-class-codes Alas, they didn't have links to the subclasses available under the 08 class (for mass storage device), and I wasn't motivated to investigate. From some cursory reading, the subclass specifies which command set to use for the device type (class). So far for the 08 MSD device class, I've found the following subclasses (command sets): 01 RBC (e.g., flash drive) 02 SFF-8020i (ATAPI precursor), MMC-2 (ATAPI) - e.g., multimedia cards 03 QIC-157 - e.g., CD-ROM, and magnetic tape 04 Floppy (UFI) 05 SFF-8070i 06 SCSI https://usb-ids.gowdy.us/read/UC/08 https://cscott.net/usb_dev/data/devclass/msco_v109.pdf, chapter 2 |
#3
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Curious about Explorer view
On Mon, 4 Mar 2019 22:43:54 -0400, pjp wrote:
Why does Explorer show external/portable disk drives as Hard Disks rather than Removable Storage? Seems to me they should be considered removable storage as that's what they actually are. In Windows, a removable storage device type is a storage device with removable storage media. e.g. floppy drive, optical drive, ZIP drive. i.e. the storage type refers to the media, not the reader device. |
#4
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Curious about Explorer view
In message , VanguardLH
writes: pjp wrote: Why does Explorer show external/portable disk drives as Hard Disks rather than Removable Storage? Seems to me they should be considered removable storage as that's what they actually are. Perhaps because the USB presentation data (for the class type) sent from the device to identify itself to the OS is for disk instead of, say, optical media or flash media, or it identifies itself as an MSD (mass storage device) but a different subclass (command set). [] If it helps, think of it as that the medium can't be removed from the drive: the drive itself can be removed (from the computer), but the media can't be removed from the drive. Compare a USB card reader, floppy drive, or optical (CD/DVD) drive: in those, the medium can be removed but the reader/drive remain connected. -- J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf science is not intended to be foolproof. Science is about crawling toward the truth over time. - Scott Adams, 2015-2-2 |
#5
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Curious about Explorer view
Wolf K wrote:
On 2019-03-04 21:43, pjp wrote: Why does Explorer show external/portable disk drives as Hard Disks rather than Removable Storage? Seems to me they should be considered removable storage as that's what they actually are. Explorer actually shows partitions, not disks. Windows assigns a "drive letter" to every user-accessible partitions. [1] The confusion between disk and partition started aeons ago, maybe because "disk" is a shorter word. Or maybe because Windows formats a disk drive as one partition by default. Or maybe because from the user's POV a partition is a separate storage device. Or... Take your pick. [1] But manufacturers may introduce inconsistency. On prebuilt systems, a recovery/repair partition may be given a drive letter. There may be a technical reason for this, if so, anyone know? You don't assign drive letters to partitions unnecessarily. If the OS isn't assigning a letter, there is probably a reason for it. On a small partition of type 0x07, you may have the ability to assign a drive letter, but once you do, the system will write "System Volume Information" at the root level of the partition. And, with carelessness, could start using storage space in there. The end result, was "partition full" warnings that the user could not figure out. And it was because they put a drive letter on something that doesn't particularly need one. If the partition type is 0x27 (hidden NTFS), then you cannot mount the partition in userland, neither can you assign a drive letter. Windows seems to be a trifle inconsistent in how it's handled those. As I could find OSes where the small partition was 0x07 and ones where it was 0x27 (hidden). In Linux, if you want to "look in there", without changing the partition type field with PTEDIT32, you can always try a loopback mount with an offset parameter, which allows mounting "anything that looks like an NTFS partition" :-) Which is a cool capability. On the Windows side, I'm not aware of an interface to allow doing that. Although it could exist. ******* The only reason for making a recovery partition visible, is if you have an EXE on there that "kicks off recovery". Normally, recovery would require a reboot, and the OS wouldn't be running while the C: is being overwritten. Some recovery partitions have a "PQ" or PowerQuest notation as their partition type. If you have such a machine, you could trace down what the partition type field is. There's some brief mention of some PowerQuest entries here. There's probably nothing particularly strange about the partition and it's actually a FAT32 or NTFS or so. By using strange values (I think Dell has a value it uses too), it prevents the end-user from getting too inquisitive. https://www.win.tue.nl/~aeb/partitio...n_types-1.html ******* And that's also why I wish this had a Windows port. As it can give you hints when nothing else is helping. It will analyze HDD and ODD and tell you the partition structure. The copy I use, is extracted from a Cygwin tree. You don't need to keep the Cygwin tree around, to run Cygwin programs. Just the two main (runtime) DLLs have to be present, for stuff to work. http://disktype.sourceforge.net/ This is an example, as run from Command Prompt... --- /dev/sdb Block device, size 931.5 GiB (1000204886016 bytes) DOS/MBR partition map Partition 1: 72.58 GiB (77934495744 bytes, 152215812 sectors from 63, bootable) Type 0x0C (Win95 FAT32 (LBA)) Windows NTLDR boot loader FAT32 file system (hints score 5 of 5) Volume size 72.56 GiB (77915455488 bytes, 2377791 clusters of 32 KiB) Partition 2: 858.9 GiB (922267745280 bytes, 1801304190 sectors from 152215875) Type 0x07 (HPFS/NTFS) NTFS file system Volume size 858.9 GiB (922267744768 bytes, 1801304189 sectors) Paul |
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