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I am writing a USB driver to a product which is basically a USB pen drive. Upon connecting the product to the usb port, I want to see the drive name/volume name as "XXXX Corporation". I see that by default it always gets shown as "Removable Disk" in Windows explorer or my computer.
If I use any USB detail reader tools available in the net, then I can see the vendor id and manufacturer ids and other usb details. Renaming the drive from windows works but I want this to happen by default without asking the end user to rename. Having autorun.inf in root of the drive works only on WindowsXP.
How do I get this? Are there any descriptors which needs to be coded explicitly in my usb drivers stack? There are already API's to obtain the manufacturer/Product/Serial descriptors in my usb drivers stack.
Thanks in advance.
Chandra
The name shown in file explorers is the filesystem label, it's not a USB descriptor. The tool you are using to create the filesystem (whether FAT or NTFS) probably allows you to set the label. It can also be changed on an existing filesystem. The label can also be read on any operating system.
The label entry of the autorun.inf file should also be read by modern Windows. Some Linux file explorers (Gnome's Nautilus) might use it if it's there, but the cross-platform way is the filesystem label.
Like in the Disk Utility, how can I get the list of connected drives who are not mounted. And then, how can I mount them ?
Thx
The Disk Arbitration framework can handle various tasks such as mounting disks:
https://developer.apple.com/library/mac/#documentation/Darwin/Reference/DiscArbitrationFramework/DiskArbitration_h/
I am not really sure how Disk Utility knows about available drives but one possibility is that it monitors mount/unmount activity (using the framework above) and simply remembers the disks that have been used in the past. For example it may automatically save the pathnames of disks in a settings file somewhere and restore that list every time it's launched.
When I boot up Linux Mint from a Live CD, I am able to save files to the "File System". But where are these files being saved to? Can't be the disc, since it's a CDR. I don't think it's stored in the RAM, because it can only hold so much data and isn't really intended to be used as a "hard drive". The only other option is the hard drive... but it's certainly not saving to any partition on the hard drive I know about, since none of them are mounted. Then where are my files being saved to??
Believe it or not, it's a ramdisk :)
All live distros mount a temporary hard disk in RAM memory. The process is completely user-transparent and is all because of the magic of Linux kernel.
The OS, in fact, first allocates an area of your RAM memory into a virtual device, then mounts it as a regular hard drive in your file system.
Once you reboot, you lose all your data from that ramdrive.
Ramdrive is needed by almost all software running on Live CDs. In fact, almost all programs, in particular desktop managers, are designed in order to write files, even temporary, during their execution.
As an example, there are two ways to run KDE on a Live CD: either modify its code deeply in order to disallow you to change wallpaper etc. (the desktop settings are stored inside ~/.kde) or redeploy it onto a writable file system such as a ramdrive in order to avoid write fails on read-only file systems.
Obviously, you can mount your real HDD or any USB drive into your virtual file system and make all writes to them permanent, but by default no live distro mounts your drives into the root file system, instead they usually mount into specific subdirectories like /mnt, /media, /windows
Hope to have been of help.
It does indeed emulate a disk using RAM; from Wikipedia:
It is able to run without permanent
installation by placing the files that
typically would be stored on a hard
drive into RAM, typically in a RAM
disk, though this does cut down on the
RAM available to applications.
RAM. In Linux, and indeed most unix systems, any kind of device is seen as a file system.
For example, to get memory info on linux you use cat /proc/meminfo, where cat is used to read files. Then, there's all sorts of strange stuff like /dev/random (to read random crap) and /dev/null (to throw away crap). ;-)
To make it persistent - use a USB device - properly formatted and with a special name. See here:
https://help.ubuntu.com/community/LiveCD/Persistence
My application writes some bytes of data to an alternate data stream. This works fine on all but one machine (Windows Server 2003 SP2).
Instead, CreateFile returns ERROR_DISK_FULL when I try to create an alternate data stream (on the root directory). I don't find the reason for this result, because...
There's plenty of space on that drive.
The drive is NTFS formatted (due to GetVolumeInformation).
The drive supports altenate data
streams (due to GetVolumeInformation).
Edit: I can provide some more information about what the reason not is:
I added many streams on a test system which didn't show the error and wondered if the error might occur. It didn't. Instead after about 2000 Streams with long file names another error occurred and persisted: 1450 (ERROR_NO_SYSTEM_RESOURCES).
EDIT: Here is an example for one of the used file names:
char szStreamFileName[] = "C:\\:abcdefghijklmnopqrstuvwxyz1234567890abcdefghijklmnoqrstuvwxyz012345";
EDIT: Our customer uses some corporate antivirus software from Avira on this server. Maybe this is the reason (Alternate data streams can be abused by malware).
After opening a support ticket at MS I know that there was a readonly flag set which one only can set (and reset) with undocumented Windows functions. Nobody knows who set this flag and why, but I sent them an image of the drive (after I got the machine from our customer) and so they figured it out. We only have a workaround in our application (We use another location if we detect this error). Meanwhile we know that some of our customers have this problem.
Are there any compressed/spare files or alternate data streams?
Often backup applications receive ERROR_DISK_FULL errors attempting to back up compressed files and this causes quite a bit of confusion when there are still several gigabytes of free space on the drive. Other issues may also occur when copying compressed files. The goal of this blog is to give the reader a more thorough understanding of what really happens when you compress NTFS files.
From Understanding NTFS Compression
Just another possibility...
Did you check the number of currently opend files in your OS?
The OS support max. number of reserved file handles after that report ERROR_DISK_FULL or ERROR_NO_SYSTEM_RESOURCES.
And second possibility...
The root directory is limited by number of files. As I remember 512 files in older versions of OS. But the NTFS support unlimited number of files in root!
You might want to see what something like Sysinternal's Process Monitor utility captures when trying to create this file - it show the return codes of various APIs involved in the I/O stack and one of them might give you a clue as to why 112 is being returned to you. Hopefully the level of detail in ProcMon is enough - if not, I imagine there are other, more detailed I/O trace facilities for Windows (but I don't know of them off the top of my head)
The filename you give is
char szStreamFileName[] = "C:\\:abcdefghijklm...
it starts with
C:\\:
Is that a typo on the post, or is there really a colon after the slash? I think thats a illegal filename.
If you try to copy a file greater than 2GB from another filesystem (NTFS) to FAT / FAT32 which has a 2GB limit you may see this error.
Just a blind shot, but are the rights set properly?
I'm need to find a method to programmatically determine which disk drive Windows is using to boot. In other words, I need a way from Windows to determine which drive the BIOS is using to boot the whole system.
Does Windows expose an interface to discover this? With how big the Windows API is, I'm hoping there is something buried in there that might do the trick.
Terry
p.s. Just reading the first sectors of the hard disk isn't reveling anything. On my dev box I have two hard disks, and when I look at the contents of the first couple of sectors on either of the hard disks I have a standard boiler plate MBR.
Edit to clarify a few things.
The way I want to identify the device is with a string which will identify a physical disk drive (as opposed to a logical disk drive). Physical disk drives are of the form "\\.\PHYSICALDRIVEx" where x is a number. On the other hand, a logical drive is identified by a string of the form, "\\.\x" where x is a drive letter.
Edit to discuss a few of the ideas that were thrown out.
Knowing which logical volume Windows used to boot doesn't help me here. Here is the reason. Assume that C: is using a mirrored RAID setup. Now, that means we have at least two physical drives. Now, I get the mapping from Logical Drive to Physical Drive and I discover that there are two physical drives used by that volume. Which one did Windows use to boot? Of course, this is assuming that the physical drive Windows used to boot is the same physical drive that contains the MBR.
Go into Control Panel
System and Security
Administrative Tools
Launch the System Configuration tool
If you have multiple copies of Windows installed, the one you are booted with will be named such as:
Windows 7 (F:\Windows)
Windows 7 (C:\Windows) : Current OS, Default OS
Unless C: is not the drive that windows booted from.Parse the %SystemRoot% variable, it contains the location of the windows folder (i.e. c:\windows).
You can use WMI to figure this out. The Win32_BootConfiguration class will tell you both the logical drive and the physical device from which Windows boots. Specifically, the Caption property will tell you which device you're booting from.
For example, in powershell, just type gwmi Win32_BootConfiguration to get your answer.
That depends on your definition of which disk drive Windows used to boot. I can think of 3 different answers on a standard BIOS system (who knows what an EFI system does):
The drive that contains the active MBR
The active partition, with NTLDR (the system partition)
The partition with Windows on it (the boot partition)
2 and 3 should be easy to find - I'm not so sure about 1. Though you can raw disk read to find an MBR, that doesn't mean it's the BIOS boot device this time or even next time (you could have multiple disks with MBRs).
You really can't even be sure that the PC was started from a hard drive - it's perfectly possible to boot Windows from a floppy. In that case, both 1 and 2 would technically be a floppy disk, though 3 would remain C:\Windows.
You might need to be a bit more specific in your requirements or goals.
You type diskpart, list disk and check disks for boot.
Ex:
dispart
list disk
select disk 0
detail disk
The disk with Boot volume is disk with windows installed:
There is no boot.ini on a machine with just Vista installed.
How do you want to identify the drive/partition: by the windows drive letter it is mapped to (eg. c:\, d:) or by how its hardware signature (which bus, etc).
For the simple case check out GetSystemDirectory
Try HKEY_LOCAL_MACHINE\SYSTEM\Setup\SystemPartition
You can try use simple command line. bcdedit is what you need, just run cmd as administrator and type bcdedit or bcdedit \v, this doesn't work on XP, but hope it is not an issue.
Anyway for XP you can take a look into boot.ini file.
a simpler way
search downloads in the start menu and click on downloads in the search results to see where it will take you the drive will be highlighted in the explorer.
On Windows 10.
Open "Computer Management"
Look for "Storage" in list "left top side of page"
select "Disk Management"
On section of page showing the list of disks and the partitions find the disk that has the partition assigned as drive C:
On that disk containing C: partition
Use the right mouse button to select the Square section containing The Disk Number, Type of drive and size in GB . When menu opens select the Properties.
A window will open showing what drive hardware was used.