87
Are you using a 64-bit version of Linux with a lot of memory? In that case the problem could be that Linux can lock for minutes on big writes on slow devices like for
example SD cards or USB sticks. It's a known bug that should be fixed in newer kernels.
See http://lwn.net/Articles/572911/
Workaround: as root issue:
echo $((16*1024*1024)) > /proc/...
80
Yes. For example:
sudo eject /dev/sda
Other answers here that indicate that you require mechanical ejection hardware are incorrect.
Unmounting is not the same thing as ejecting.
If you unmount a volume, you can immediately mount it back, because the underlying device is still available. In some situations, this could present a security risk. By ejecting ...
65
Suppose your usb drive is mounted to /media/usb then it would be sufficient to do
sudo umount /media/usb
Suppose the your usb is /dev/sdb1 then you could also do
sudo umount /dev/sdb1
You may also have a look at the anwers of one of my questions, how to umount all attached usb devices with a single command: Umount all attached usb disks with a single ...
40
There is a vendor independent SAT (SCSI/ATA transfer) standard, but AFAIK this is not widely supported on (cheaper) bridges.
There are several vendor specific ATA pass-through commands that you can select with smartctl with the -d option:
-d TYPE, --device=TYPE
Specify device type to one of: ata, scsi, sat[,N][+TYPE],
usbcypress[,X], usbjmicron[,...
39
eject will work, but will not really "finish the job" regarding USB rotating drives.
The best way to unplug a USB external hard-drive, after proper unmounting, is:
udisks --detach /dev/sdb
This usually causes the drive to spin down gracefully.
Precisely, the current implementation:
sends SCSI sync-cache command,
sends SCSI stop command,
unbinds ...
39
To create a bootable USB, you can follow the steps below:
STEP 1
Go to the website of the OS you wish to install, and find an iso image to download. In your case, since you want to run a Debian OS, here is a link to its iso options: https://www.debian.org/distrib/netinst
Choose an iso image from the options, and click on it. This should automatically ...
26
qemu-kvm has disappeared. use the hint in start qemu by giving it a path to a linux root instead. this means
qemu-system-x86_64 -usb -usbdevice disk:/dev/sdb
where /dev/sdb is your raw device (not partition) of the usb stick that you want to boot.
(however, as of 12/2014, it's been flaky for me. booting ubuntu-gnome 14.10 results eventually in a kernel ...
23
qemu-kvm -hdb <device>, where <device> is the USB stick (e.g. /dev/sdb), should do it (tested with Ubuntu 12.04 on an USB stick and it works).
You will need write permission to the device (i.e. be root or change its permissions).
23
SCSI is not only a type of hardware interface, but also a command protocol, which is used for abstraction of most of the modern storage devices. Linux scsi driver is a high level driver that handles a variety of storage hardware.
Protocol:
http://en.wikipedia.org/wiki/SCSI_command
Extract from SCSI on wikipedia:
Other technologies which use the SCSI ...
22
systemd-udevd runs in its own file system namespace and by default mounts done within udev .rules do not propagate to the host. To make your old scripts work you can set MountFlags=shared in /usr/lib/systemd/system/systemd-udevd.service or (better) creating and editing its copy at /etc/systemd/system/
See man 5 systemd.exec for more information, MountFlags ...
17
The problem with the timestamp seconds changing comes from the fact that a VFAT (yes, even FAT32) filesystem stores the modification time with only 2-second resolution.
Apparently, as long as the filesystem is mounted, the filesystem driver caches timestamps accurate to 1-second resolution (probably to satisfy POSIX requirements), but once the filesystem ...
16
This is the behavior I have on my Ubuntu Lucid system:
When I plug in my USB flash/thumbdrive which has two partitions, the system reports:
$ ls /dev/sdb*
/dev/sdb /dev/sdb1 /dev/sdb2
$ udisks --show-info /dev/sdb | grep -A2 'partition table\|by-id'
by-id: /dev/disk/by-id/usb-takeMS_USB_Mini_AA07013000010057-0:0
by-path: ...
16
No. Nor do they need to be; eject is used for opening optical drives, where one cannot pull the media from directly.
Unmounting is sufficient for USB/eSATA/etc. storage devices.
answered Apr 2 '12 at 0:40
Ignacio Vazquez-Abrams
36.1k6 gold badges76 silver badges86 bronze badges
16
This is Gilles' answer, saving it here so it doesn't get lost.
If you use the sync mount option on the removable drive, all writes are written to the disk immediately, so you won't lose data from not-yet-written files. It's a bad idea, but it does what you're asking, kind of.
Note that sync does not guarantee that you won't lose data. Unmounting a ...
16
Like any unix-style filesystem, ext4 includes standard Unix file ownership and permission conventions. That is, the user is identified by an UID number, and each user will belong to one or more groups, each group identified by its GID number. Each file has an owner UID and one group owner GID. The three classic Unix file permission sets are:
one set of ...
12
The problem seems to be a catchall rule in /lib/udev/rules.d/69-libmtp.rules:
# Autoprobe vendor-specific, communication and PTP devices
ENV{ID_MTP_DEVICE}!="1", ENV{MTP_NO_PROBE}!="1", ENV{COLOR_MEASUREMENT_DEVICE}!="1", ENV{libsane_matched}!="yes", ATTR{bDeviceClass}=="00|02|06|ef|ff", PROGRAM="/usr/lib/udev/mtp-probe /sys$env{DEVPATH} $attr{busnum} $attr{...
12
Following method works with CentOS 6.2:
Requirements: USB flash drive (at least 4 GB, I used a 16 GB one)
Download an ISO image from a mirror - I chose the full 1st DVD image to avoid a network install (because it is not clear if the cryptographic package signatures are checked by the installer or not), e.g.:
$ wget http://ftp.uni-bayreuth.de/linux/CentOS/...
12
Patient: "Doctor, It hurts when I do this."
Doctor: "Well, don't do that."
— maybe the Marx Brothers, but they probably stole it from other vaudevillians if so
Both answers are fine, but I do question the question. If you can't remember to unmount a thumbdrive properly before removing it, perhaps you should remember harder.
In general, the problem ...
12
Looks like this device is mounted. Run umount /dev/sdb1 and try again.
11
Was the name of the device U167CONTROLLER before?
It may be that the microcontroller on the device has encountered some abnormal condition (totally possible with less than totally reputable manufacturers) and needs to be reprogrammed. This is a bit of a black art and it's likely you will only find Windows programs that can reprogram the microcontroller.
...
11
If you use the sync mount option on the removable drive, all writes are written to the disk immediately, so you won't lose data from not-yet-written files. It's a bad idea, but it does what you're asking, kind of.
Note that sync does not guarantee that you won't lose data. Unmounting a removable drive also ensures that no application has a file open. If you ...
answered Sep 11 '13 at 0:04
Gilles 'SO- stop being evil'
601k145 gold badges1233 silver badges1744 bronze badges
11
If a USB flash device and USB cdrom is connected then only difference that I can find out is their kernel driver.
Both uses the common usb and usb-storage kernel module but in addition to that CD-ROM uses sr module while USB uses the sd module.
Based on this info, you can write UDEV rule
10
Yes, this can occur if your device is formatted with a filesystem that does not support that kind of permission setting, such as VFAT. In those cases, the umask is made up on the fly from a setting in the fstab (or the hotplugging equivalent).
See, most probably, man mount for details. For example, for VFAT, we find:
Mount options for fat
uid=value ...
10
Have a look under the /sys/ directory. In particular, /sys/block/ contains symlinks to block devices in /sys/devices/.
/sys/block/sdX/removable looks like it will read as 1 for a removable device, and 0 otherwise. This gives you a basic check for removability.
I'm not sure if there's a better way to check if it's a USB device, but
readlink /sys/block/sde ...
9
Manual steps for unmounting disk /dev/sdb (Requires sudo):
echo 'offline' > /sys/block/sdb/device/state
echo '1' > /sys/block/sdb/device/delete
This will completely power-off the device and detach it from the system. It won't be detected again till it is disconnected and re-attached.
9
You can use graphical tools to achieve this, such as GParted. You can install this like so:
apt-get update
apt-get install gparted
Your OS may also include a graphical package manager, if so, you can alternatively install the gparted package from there.
After gparted is installed, run it. Select your flash drive (be careful, make sure it is the right ...
9
Your 8GB stick has approximately 7.5 GiB and even with some file system overhead should be able to store the 5.4GiB file.
You use tune2fs to check the file sytem status and properties:
tune2fs -l /dev/<device>
By default 5% of the space is reserved for the root user. Your output lists 97894 blocks, which corresponds to approximately 385MiB and seems ...
9
I have just successfully formatted a completely blank floppy in a USB drive. This required a proper format, and not just writing a filesystem to the disk, because there were no sectors on it yet.
This is done with the ufiformat program, which is specifically designed to work with USB floppy drives.
$ sudo ufiformat -f 1440 -v /dev/sdd
format on device=/...
9
Turns out that there's a 1 second timeout int drivers/usb/storage/usb.c. I enabled more debug-logging by typing the following two commands:
echo 8 > /proc/sys/kernel/printk
echo "module usb_storage +p" > /sys/kernel/debug/dynamic_debug/control
echo 0xFFFFFF > /proc/sys/dev/scsi/logging_level
The scsi subsystem has a weird (compared to the rest of ...
9
I suspect you are using a mount command like the one below:
mount -t msdos /dev/XYZ /mnt/test
This will force the partition to be mounted in legacy DOS FAT filesystem which uses the 8.3 filename convention (See https://en.wikipedia.org/wiki/8.3_filename) instead of vfat which uses Long filenames (https://en.wikipedia.org/wiki/Long_filename).
...
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