Difference between revisions of "USB storage devices"

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(Auto-mounting with udev: Alter udev rule so it won't interfere with sda*, use partition's label if it exists, remove sudo)
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[[Category:Storage]]
 
[[Category:Storage]]
[[es:USB Storage Devices]]
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[[es:USB storage devices]]
[[it:USB Storage Devices]]
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[[fr:Périphérique de stockage USB]]
[[ru:USB Storage Devices]]
+
[[it:USB storage devices]]
This document describes how to use the popular USB memory sticks with Linux. However, it is also valid for other devices such as digital cameras that act as if they were just a USB storage device.
+
[[ja:USB ストレージデバイス]]
 +
[[ru:USB storage devices]]
 +
{{Related articles start}}
 +
{{Related|Mount}}
 +
{{Related articles end}}
  
== Mounting USB devices ==
+
This document describes how to use the popular USB memory sticks with Linux. However, it is also valid for other devices such as digital cameras that act as if they were just a USB storage device.
  
 
If you have an up-to-date system with the standard Arch kernel and a modern [[Desktop environment]] your device should just show up on your desktop, with no need to open a console.
 
If you have an up-to-date system with the standard Arch kernel and a modern [[Desktop environment]] your device should just show up on your desktop, with no need to open a console.
  
Otherwise see sections below.
+
== Auto-mounting with udisks ==
  
=== Auto-mounting with udev ===
+
This is the easiest and most frequently used method. It is used by many [[desktop environments]], but can be used separately too. See [[Udisks]] for details.
  
See [[Udev#Auto mounting USB devices|Udev:Auto mounting USB devices]].
+
== Manual mounting ==
 
+
A lightweight solution to automount drives using udev, '''for single-user systems''', is the following: create a file named {{ic|/etc/udev/rules.d/automount.rules}} with the following content:
+
{{bc|<nowiki>
+
# ignore sda*
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KERNEL!="sd[b-z]*", GOTO="end"
+
 
+
# run the script
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ACTION=="add", ENV{ID_BUS}=="usb", ENV{DEVTYPE}=="partition", RUN+="domount %N"
+
 
+
# exit
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LABEL="end"
+
</nowiki>}}
+
and a file (executable by root) named {{ic|/usr/lib/udev/domount}} with  (set the variables on top to the correct values):
+
 
+
{{bc|<nowiki>
+
#!/bin/sh
+
 
+
#edit the following variables to suit your needs
+
MYUID=1000              # your user uid
+
MYGID=100              # your user gid
+
MYLOGIN=al              # your login
+
TERM=lxterminal        # your terminal emulator
+
MYSHELL=zsh            # your shell
+
export DISPLAY=:0      # your X display
+
 
+
 
+
TMPFILE=/run/automount.$RANDOM
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DIR=$(grep -v '#' /etc/fstab | grep $* | awk '{print $2;}')
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if [ -z "$DIR" ]; then
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    LABEL=$(lsblk -no LABEL $*)
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    if [ -z "$LABEL" ]; then
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        UUID=$(lsblk -no UUID $*)
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        if [ -z "$UUID" ]; then
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            DIR=/run/media/"unknown"
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        else
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            DIR=/run/media/"$UUID"
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        fi
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    else
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        DIR=/run/media/"$LABEL
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    fi
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fi
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mkdir -p $DIR
+
 
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cat > $TMPFILE << EOF
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#!/bin/sh
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echo "$* was mounted on $DIR. "
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cd $DIR
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$MYSHELL
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EOF
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chmod a+x $TMPFILE
+
 
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/bin/mount -o uid=$MYUID,gid=$MYGID $* $DIR
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su $MYLOGIN -c "$TERM -t 'Terminal - $* mounted on $DIR' -e $TMPFILE"
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/bin/umount $DIR
+
 
+
sleep 1; rm -f $TMPFILE
+
</nowiki>}}
+
 
+
When a drive is inserted, it will be mounted, and a Terminal will pop-up. To umount the device, simply press Control+D in the terminal window. The mountpoint is looked for in {{ic|/etc/fstab}} or, if absent, generated from the label of the partition.
+
 
+
If the terminal doesn't appear as expected, that may because wrong options are used. For example, in XFCE4, we use "Terminal -T ''title'' -e ''script-file'' instead"
+
 
+
=== Manual mounting ===
+
  
 
{{Note|Before you decide that Arch Linux does not mount your USB device, be sure to check all available ports. Some ports might not share the same controller, preventing you from mounting the device.}}
 
{{Note|Before you decide that Arch Linux does not mount your USB device, be sure to check all available ports. Some ports might not share the same controller, preventing you from mounting the device.}}
  
==== Getting a kernel that supports usb_storage ====
+
=== Getting a kernel that supports usb_storage ===
  
If you do not use a custom-made kernel, you are ready to go, for all Arch Linux stock kernels are properly configured. If you do use a custom-made kernel, ensure it is compiled with SCSI-Support, SCSI-Disk-Support and usb_storage. If you use the latest [[udev]], you may just plug your device in and the system will automatically load all necessary kernel modules. Older releases of udev would need hotplug installed too. Otherwise, you can do the same thing manually:
+
If you do not use a custom-made kernel, you are ready to go, for all Arch Linux stock kernels are properly configured. If you do use a custom-made kernel, ensure it is compiled with SCSI-Support, SCSI-Disk-Support and usb_storage. If you use the latest [[udev]], you may just plug your device in and the system will automatically load all necessary kernel modules.
  
# modprobe usb-storage
+
=== Identifying device ===
# modprobe sd_mod      (only for non SCSI kernels)
+
  
==== Identifying device ====
+
The first thing one needs to access a storage device is its identifier assigned by kernel. See [[fstab#Identifying filesystems]] for details.
  
First thing one need to access storage device is it's identifier assigned by kernel.
+
{{Tip|To see which device is your USB device, you can compare the output of {{ic|lsblk -f}} (explained in the linked article) when the USB device is connected and when it is unconnected.}}
  
===== Using device node names ( /sd* ) =====
+
=== Mounting USB memory ===
  
This is the simplest way, but assigned name depends on order of insertion. Ways to get node name:
+
You need to create the directory in which you are going to mount the device:
  
* search in the output of {{ic|dmesg}} for the kernel device name, you can use {{ic|grep}} to help you find what you are looking for:
 
$ dmesg | grep -E "sd[a-z]"
 
* List all available partition tables:
 
# fdisk -l
 
 
{{Note|If you cannot find your device you can use lsusb to verify that it is indeed recognized by the system.}}
 
 
===== Using UUID =====
 
 
Every drive creates a [[Wikipedia:UUID|UUID]] (Universally Unique Identifier), these identifiers can be used to track individual drive no matter their device node (i.e. {{ic|/dev/sda}}).
 
 
To find the current UUIDs execute (as root):
 
{{hc|# blkid -o list -c /dev/null|<nowiki>
 
device        fs_type  label    mount point        UUID
 
------------------------------------------------------------------------------------------
 
/dev/sda1      ext2              /boot              7f4cef7e-7ee2-489a-b759-d52ba23b692c
 
/dev/sda2      swap              (not mounted)      a807fff3-e89f-46d0-ab17-9b7ad3efa7b5
 
/dev/sda3      ext4              /                  81917291-fd1a-4ffe-b95f-61c05cfba76f
 
/dev/sda4      ext4              /home              c4c23598-19fb-4562-892b-6fb18a09c7d3
 
/dev/sdb1      ext4    X2        /mnt/X1            4bf265f7-da17-4575-8758-acd40885617b
 
/dev/sdc1      ext4    X1        /mnt/X2            4bf265f7-da17-4575-8758-acd40885617b
 
/dev/sdd1      ext4    Y2        /mnt/Y2            8a976a06-3e56-476f-b73a-ea3cad41d915
 
/dev/sde1      ext4    Z2        /mnt/Z2            9d35eaae-983f-4eba-abc9-434ecd4da09c
 
/dev/sdf1      ext4    Y1        /mnt/Y1            e2ec37a9-0689-46a8-a07b-0609ce2b7ea2
 
/dev/sdg1      ext4    Z1        /mnt/Z1            9fa239c1-720f-42e0-8aed-39cf53a743ed
 
/dev/sdj1      ext4    RAPT      (not mounted)      a9ed7ecb-96ce-40fe-92fa-e07a532ed157
 
/dev/sdj2      swap              <swap>            20826c74-eb6d-46f8-84d8-69b933a4bf3f
 
</nowiki>}}
 
 
Or to find this information with non-root privileges, use:
 
{{hc|$ lsblk -o name,kname,uuid|<nowiki>
 
NAME                    KNAME UUID
 
sda                      sda 
 
├─sda1                  sda1  A103-2001
 
└─sda2                  sda2  6i2E71-zJzL-KXuG-juYv-mbNY-kROA-XsIPlm
 
  ├─vg0-var (dm-0)      dm-0  cebi84r5-0401-491e-a0d6-de0j3bnw867c
 
  ├─vg0-home (dm-1)      dm-1  cceguid6-f3mc-4d7a-a1f2-83f2mkpds3q1
 
  └─vg0-root (dm-2)      dm-2  973ed4rf-6611-47ed-877c-b66yhn5tgbc7
 
sdb                      sdb 
 
└─sdb1                  sdb1  j1Pr1X-b0uM-bkWZ-KNYQ-gezL-YliV-ScRufFyD
 
  └─vg0-home (dm-1)      dm-1  cefmkbe6-f4n8-4d7a-al32-83f259ijn6t7
 
sr0                      sr0 
 
</nowiki>}}
 
 
 
At this point you should see a list of your system drives and a long strings of characters. These long strings are the UUIDs.
 
 
* Now connect your USB device and wait for a few seconds . . .
 
 
* Reexecute {{ic|blkid -o list -c /dev/null}}
 
Notice a new device and UUID? That is your USB storage.
 
 
{{Tip|If {{ic|blkid}} does not work as expected, You can look for the UUIDs in {{ic|/dev/disk/by-uuid/}}:
 
$ ls -lF /dev/disk/by-uuid/
 
}}
 
 
==== Mounting USB memory ====
 
 
You need to create the directory in which you are going to mount the device:
 
 
  # mkdir /mnt/usbstick
 
  # mkdir /mnt/usbstick
  
===== As root =====
+
==== As root ====
  
 
Mount the device as root with this command (do not forget to replace '''device_node''' by the path you found):
 
Mount the device as root with this command (do not forget to replace '''device_node''' by the path you found):
 +
 
  # mount '''device_node''' /mnt/usbstick
 
  # mount '''device_node''' /mnt/usbstick
 +
 
or
 
or
 +
 
  # mount -U '''UUID''' /mnt/usbstick
 
  # mount -U '''UUID''' /mnt/usbstick
  
 
If {{ic|mount}} does not recognize the format of the device you can try to use the {{ic|-t}} argument, see {{ic|man mount}} for details.
 
If {{ic|mount}} does not recognize the format of the device you can try to use the {{ic|-t}} argument, see {{ic|man mount}} for details.
  
{{Note|If mounting your stick does not work you can try to repartition it, see [[Format a device]].}}
+
{{Note|
 +
* If mounting your stick does not work you can try to repartition it, see [[Format a device]].
 +
* See [https://gist.github.com/anonymous/a69093a51f83b53d9fc5] for example mount/unmount scripts using [[sudo]].
 +
}}
  
===== As normal user with mount =====
+
==== As normal user with mount ====
  
 
If you want non-root users to be able to write to the USB stick, you can issue the following command:
 
If you want non-root users to be able to write to the USB stick, you can issue the following command:
Line 173: Line 60:
 
  # mount -o gid=users,fmask=113,dmask=002 /dev/sda1 /mnt/usbstick
 
  # mount -o gid=users,fmask=113,dmask=002 /dev/sda1 /mnt/usbstick
  
===== As normal user with fstab =====
+
==== As normal user with fstab ====
  
If you want non-root users to be able to mount a USB memory stick via [[fstab]], add the following line to your {{ic|/etc/fstab}} file:
+
See [[Fstab#Writing to FAT32 as Normal User]] if you want normal user to do the mount/unmount action.
/dev/sda1 /mnt/usbstick vfat '''user''',noauto,noatime,flush 0 0
+
or better:
+
UUID=E8F1-5438 /mnt/usbstick vfat '''user''',noauto,noatime,flush 0 0
+
(see description of '''user''' and other options in the [[Fstab|main article]])
+
 
+
{{Note|Where {{ic|/dev/sda1}} is replaced with the path to your own usbstick, see [[USB_Storage_Devices#Mounting_USB_memory|Mounting USB memory]].}}
+
 
+
Now, any user can mount it with:
+
$ mount /mnt/usbstick
+
 
+
And unmount it with:
+
$ umount /mnt/usbstick
+
 
+
===== Poor copy performance to USB pendrive  =====
+
 
+
If you experienced slow copy speed to pendrive (mainly in KDE), then append these three lines in a [[systemd]] tmpfile:
+
{{hc|/etc/tmpfiles.d/local.conf|
+
w /sys/kernel/mm/transparent_hugepage/enabled - - - - madvise
+
w /sys/kernel/mm/transparent_hugepage/defrag - - - - madvise
+
w /sys/kernel/mm/transparent_hugepage/khugepaged/defrag - - - - 0
+
}}
+
And paste these at the end of your {{ic|/etc/sysctl.conf}}:
+
kernel.shmmax=134217728
+
vm.dirty_background_bytes = 4194304
+
vm.dirty_bytes = 4194304
+
Reboot. This also reduces the freezes of the KDE's panel.
+

Latest revision as of 19:52, 24 July 2016

Related articles

This document describes how to use the popular USB memory sticks with Linux. However, it is also valid for other devices such as digital cameras that act as if they were just a USB storage device.

If you have an up-to-date system with the standard Arch kernel and a modern Desktop environment your device should just show up on your desktop, with no need to open a console.

Auto-mounting with udisks

This is the easiest and most frequently used method. It is used by many desktop environments, but can be used separately too. See Udisks for details.

Manual mounting

Note: Before you decide that Arch Linux does not mount your USB device, be sure to check all available ports. Some ports might not share the same controller, preventing you from mounting the device.

Getting a kernel that supports usb_storage

If you do not use a custom-made kernel, you are ready to go, for all Arch Linux stock kernels are properly configured. If you do use a custom-made kernel, ensure it is compiled with SCSI-Support, SCSI-Disk-Support and usb_storage. If you use the latest udev, you may just plug your device in and the system will automatically load all necessary kernel modules.

Identifying device

The first thing one needs to access a storage device is its identifier assigned by kernel. See fstab#Identifying filesystems for details.

Tip: To see which device is your USB device, you can compare the output of lsblk -f (explained in the linked article) when the USB device is connected and when it is unconnected.

Mounting USB memory

You need to create the directory in which you are going to mount the device:

# mkdir /mnt/usbstick

As root

Mount the device as root with this command (do not forget to replace device_node by the path you found):

# mount device_node /mnt/usbstick

or

# mount -U UUID /mnt/usbstick

If mount does not recognize the format of the device you can try to use the -t argument, see man mount for details.

Note:
  • If mounting your stick does not work you can try to repartition it, see Format a device.
  • See [1] for example mount/unmount scripts using sudo.

As normal user with mount

If you want non-root users to be able to write to the USB stick, you can issue the following command:

# mount -o gid=users,fmask=113,dmask=002 /dev/sda1 /mnt/usbstick

As normal user with fstab

See Fstab#Writing to FAT32 as Normal User if you want normal user to do the mount/unmount action.