I'm having problem to use this command under windows
dd if=*file* of=/dev/sdx bs=512 seek=2 conv=fsync
Using cygwin shell:
$ dd if=file of=/cygdrive/f bs=512 seek=2 conv=fsync
dd: failed to open ‘/cygdrive/f’: Is a directory
F: is the letter where my SD Card is mapped. What's the way to access it?
As you wrote dd if=file of=/dev/sdx
so you need to identify the device name sdx equivalent for your disk F:
On my system:
$ cat /proc/partitions
major minor #blocks name win-mounts
8 0 175825944 sda
8 1 175824896 sda1 C:\
8 16 1953514582 sdb
8 17 1953512448 sdb1 E:\
so /dev/sdb is the full USB hardisk and /dev/sdb1 is the first partition.
Pay attention to what you are doing. dd is a dangerous tool and can destroy your data/system
I never did find a good way to explicitly map a windows drive to a Cygwin drive but I did find a great alternate way to solve the problem/use dd on a windows machine.
dd is actually part of the package installed/shipped with Git for Windows. Once that is installed/unzipped if using the portable version you can find the binary in C:\Program Files\Git\usr\bin\dd.exe
The hardware mapping equivalent for if/of setting is written in the notation \.\DEVICENAME0 and can be found by running this PowerShell command (as-written also returns sector size)
Get-WmiObject Win32_diskdrive | select Caption,DeviceID,BytesPerSector,InterfaceType,Size
Related
'uname -a' on my machine gives:
Linux ct-lt-966 4.9.0-8-amd64 #1 SMP Debian 4.9.144-3.1 (2019-02-19) x86_64 GNU/Linux
Currently the filesystem of my USB is MS-DOS 'FAT32' which has a ~4.5 GB maximum size for individual files. I want to change this filesystem to something else, which does not have a limit. (I am trying to put a 35GB file onto a 64GB USB but I believe most USB filesystems do not limit the size of individual files).
I have not found it clear what choices of USB filesystem that I have. I tried to change the filesystem to 'NTFS', but I could not install or locate 'mkfs.ntfs' or even 'ntfsprogs'. (I also tried installing with 'pacman' and 'yum' but apparently 'pacman' requires an aarch architecture and I could not get access to 'yum-config-manager' in order to enable any repos).
So to conclude, with my minimal prowess I am just looking for any way to change the filesystem of my 64GB USB to anything which will accept a 35GB file from my machine.
Thanks
Edit 1: Just planning to use the USB on this Linux machine, not Windows.
If there's nothing on the stick you want, or it's safe to delete it then basically:
delete the current FAT32 partition from the stick
add a new partition, utilising the full size of the device
create an ext4 filesystem on the new partition
PLEASE BE CAREFUL WITH THIS PROCESS: selecting the wrong device can obliterate a disk you needed such as a $HOME or your root OS
All the following is from memory and untested: I don't have a USB stick available right now to test fully.
Start by plugging in the stick while tailing the syslog in a console and see where it gets mounted (hopefully it automounts which it should if it's a desktop based Linux you're running. Possibly not if it's a server)..
sudo tail -f /var/log/syslog
(it might be /var/log/messages depending on distro)
then plug the stick. syslog should show it being allocated a device and a mount point. A file manager window may open depending on your config if you are in a GUI. For example, you might see it being loaded on /dev/sdc1 and mounted at /media/<yourusername>/USBKEY or something.
Confirm by running lsblk and note the device for the key, i.e.
$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 167.7G 0 disk
├─sda1 8:1 0 69.9G 0 part /
└─sda2 8:2 0 97.9G 0 part /home
sdb 8:16 0 149.1G 0 disk
└─sdb1 8:17 0 149.1G 0 part /mnt/snapshots
sdc 8:32 0 931.5G 0 disk
└─sdc1 8:33 0 931.5G 0 part /storage
sdd 8:48 0 465.8G 0 disk
└─sdd1 8:49 0 465.8G 0 part /mnt/backup
sr0 11:0 1 1024M 0 rom
Unmount the stick (if it mounted) but leave it plugged in. Assuming again your device is at /dev/sdc1...
umount /dev/sdc1
Now run cfdisk in a terminal if you have it (friendlier) or fdisk if not, passing it the device related to your USB stick, without the partition number.
man cfdisk
sudo cfdisk /dev/sdc
This should show the current FAT32 partition. Delete it, then create a new partition of type 'Linux', following the defaults for start and end blocks which will be suggested in such a way as to fill the available space.
When done, select the option to Write the changes. Again, DOUBLE AND TRIPLE CHECK you have the right device or you will blow away your main disk probably.
Once the changes are written, you can create the ext4 file system;
sudo mkfs.ext4 /dev/sdc1
And after it completes, you should be able to re-plug your stick and find that it remounts, this time with a file system that can take your large files.
This isn't the only way to achieve this, but it's probably the least fiddly. For the sake of repetition, don't make a mistake with the device identifiers. If you're unsure, ask.
I'm trying to recover some data from a hard drive extracted from a broken laptop, and I'm having problems mounting the disk to my current system (Linux Mint). The hard disk I'm recovering from ran Debian. Simply, I'm confused as to how I can mount the hard drive to access the files, however it's not as simple as any other mount I've done. The following details struggles and information I've encountered.
I get the following outputs when trying to mount the hard drive with different file-system tags. I should add that the file-system type isn't automatically detected when using auto, and "sdb" is definitely the correct address for the disk (taken it from dmesg).
$ mount /dev/sdb /mnt/usb -t ntfs
NTFS signature is missing.
Failed to mount '/dev/sdb': Invalid argument
The device '/dev/sdb' doesn't seem to have a valid NTFS.
Maybe the wrong device is used? Or the whole disk instead of a
partition (e.g. /dev/sda, not /dev/sda1)? Or the other way around?
The following returns the same message when all other common file-system tags are used:
$ sudo mount /dev/sdb usb -t ext2
mount: wrong fs type, bad option, bad superblock on /dev/sdb,
missing codepage or helper program, or other error
In some cases useful info is found in syslog - try
dmesg | tail or so
The results from these commands led me to believe that there was an issue with the hard disk and it's partitions, however fdisk proved that it's partition's do seem to be valid and correct:
$ sudo fdisk /dev/sdb -l
Disk /dev/sdb: 250.1 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders, total 488397168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0002da94
Device Boot Start End Blocks Id System
/dev/sdb1 * 2048 475920383 237959168 83 Linux
/dev/sdb2 475922430 488396799 6237185 5 Extended
/dev/sdb5 475922432 488396799 6237184 82 Linux swap / Solaris
I then decided to try verify the file-system type of the hard drive, which seems to be "devtmpfs", which I got from the following command using df:
$ df /dev/sdb -T
Filesystem Type 1K-blocks Used Available Use% Mounted on
udev devtmpfs 1014764 4 1014760 1% /dev
And so finally, I mount the hard drive using -t devtmpfs, which is successful in mounting however I'm left with a confusing file system very unlike from what I would expect from what was a standard debian set up.
It contains file folders such as "block","bus","char","disk","dri","mapper"... and files like "sda1","sdb","sdb1","tty","vcs".
I'm totally stumped as to how I should progress, and I'm pretty convinced the hard disk isn't broken and that I'm just mounting it incorrectly. How can I successfully mount the disk so I can access my files? Any help would be greatly appreciated.
Ok, you are trying to mount the entire disk instead of individual partitions, which is why you are getting the error. In short the command you need is:
mount /dev/sdb1 /mnt/usb
The file /dev/sdb references the entire disk as a block file. This includes the partition table at the start, which is why it can't find a filesystem. The file /dev/sdb1 references the first partition, which is where your filesystem will be. From the looks of your fdisk output, this is not an ntfs partition since this is a Windows filesystem and the partition is marked as Linux (most likely you will have ext4 unless you specifically set up something different).
To add a quick explanation of devtmpfs, this is a special filesystem which contains these block files which are specified by udev. You can google both for more information, but by now I'm sure you now know its not what you are looking for.
Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.
This question does not appear to be about programming within the scope defined in the help center.
Closed 9 years ago.
Improve this question
Please do not waste anymore of your time on this question...I ended up deleting the whole VM and creating another. The time it took me to do this is less than the time it would take to fix the issue. I have couple of SSDs in RAID mode.
Thank you for all those who tried to troubleshoot the issue!
I am having this problem with ubnuntu not showing active swap spaces when I run the command cat /proc/swaps. Here is a list of commands I ran. I even added a new swap space (file: /swapfile1) just to make sure that at least one swap space, but still I get nothing.
hebbo#ubuntu-12-lts:~$ sudo fdisk -l
[sudo] password for hebbo:
Disk /dev/sda: 26.8 GB, 26843545600 bytes
255 heads, 63 sectors/track, 3263 cylinders, total 52428800 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000e3a7a
Device Boot Start End Blocks Id System
/dev/sda1 * 46569472 52426751 2928640 82 Linux swap / Solaris
/dev/sda2 2046 46567423 23282689 5 Extended
/dev/sda5 2048 46567423 23282688 83 Linux
Partition table entries are not in disk order
hebbo#ubuntu-12-lts:~$ sudo su
root#ubuntu-12-lts:/home/hebbo# cat /proc/swaps
Filename Type Size Used Priority
root#ubuntu-12-lts:/home/hebbo# dd if=/dev/zero of=/swapfile1 bs=1024 count=524288
524288+0 records in
524288+0 records out
536870912 bytes (537 MB) copied, 1.18755 s, 452 MB/s
root#ubuntu-12-lts:/home/hebbo# mkswap /swapfile1
Setting up swapspace version 1, size = 524284 KiB
no label, UUID=cb846612-5f27-428f-9f83-bbe24b410a78
root#ubuntu-12-lts:/home/hebbo# chown root:root /swapfile1
root#ubuntu-12-lts:/home/hebbo# chmod 0600 /swapfile1
root#ubuntu-12-lts:/home/hebbo# swapon /swapfile1
root#ubuntu-12-lts:/home/hebbo# cat /proc/swaps
Filename Type Size Used Priority
root#ubuntu-12-lts:/home/hebbo#
Any idea how to fix this?
This is ubuntu 12.04 LTS running kernel 3.9.0 in a vmware VM.
Thanks in advance!
To activate /swapfile1 after Linux system reboot, add entry to /etc/fstab file. Open this file using a text editor such as vi:
# vi /etc/fstab
Add the following line:
/swapfile1 swap swap defaults 0 0
Save and close the file. Next time Linux comes up after reboot, it enables the new swap file for you automatically.
Have a look here for more info.
I just tried it and it works on my box.
Linux fileserver 3.8.0-32-generic #47~precise1-Ubuntu SMP Wed Oct 2 16:19:35 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
ortang#fileserver:~$ cat /proc/swaps
Filename Type Size Used Priority
/dev/dm-2 partition 4194300 0 -1
ortang#fileserver:~$ sudo su
root#fileserver:/home/ortang# dd if=/dev/zero of=/swapfile bs=1M count=512
512+0 records in
512+0 records out
536870912 bytes (537 MB) copied, 0.695721 s, 772 MB/s
root#fileserver:/home/ortang# chmod 600 /swapfile
root#fileserver:/home/ortang# mkswap /swapfile
Setting up swapspace version 1, size = 524284 KiB
no label, UUID=63cdcf3d-ba03-42ce-b598-15b6aa3ca67d
root#fileserver:/home/ortang# swapon /swapfile
root#fileserver:/home/ortang# cat /proc/swaps
Filename Type Size Used Priority
/dev/dm-2 partition 4194300 0 -1
/swapfile file 524284 0 -2
One thing i can imagine why it is working on my box, is that i already have a working swap partition, and it seems you don't.
It could also be caused by the kernel you use, 3.9.0 is not the regular 12.04.3 LTS kernel? Have you built the kernel yourself?
Whats the output of
grep CONFIG_SWAP /boot/config-`uname -r`
or
zcat /proc/config.gz | grep CONFIG_SWAP
is swap enabled in your kernel?
I ended up deleting the whole VM and creating another. The time it took me to do this is less than the time it would take to fix the issue. I have couple of SSDs in RAID mode. And I already had all the downloads on the same host machine. All in all ~7 minutes.
Thanks for all those who helped troubleshoot the issue.
I have two hard drives:
sda ST3500...blabla (doesn't matter) and sdb WD...blabla. I want to clone sda to sdb using dd.
I ran:
dd if=/dev/sda of=/dev/sdb bs=4096 conv=notrunc,noerror,sync.
The problem is that dd also clones the label of sda (ST3500...) onto sdb. While booting SUSE from sdb it searches for WD... and fails to boot. Is there a way to clone a whole drive with dd and maintaining the target drive label/model information?
The label is in the filesystem, not in the hard drive. It can be modified by filesystem tools such as tune2fs -L for ext2/3/4 filesystems. Simply modify the label after cloning.
you can change the label manually after cloning
I started a thread here for a debian system but I am sure it will also apply for SUSE
debian forum link
We have a few linux based (Centos) virtual machines which are to be used as distributable virtual appliances. We want to be able to compress them as much as possible for distribution ( via tar.gz, zip, etc).
We've removed all unnecessary files (.log's, /tmp/*, /var/log/, etc) and have written /dev/zero to the free space on the disk.
Is it possible to write zeros via /dev/zero to the swap partitions and files? I know I would need to swapoff -a first. I'm worried about corrupting any internal structures.
Our vm uses both partition swap and file swap.
Also, are there any other strategies for reducing the size of a VM for distribution?
We need to support all of the hypervisor technologies (Xen, VMW, etc), so although the vendors tools maybe useful, I'm looking for strategies that are cross platform.
--- Thanks
You may want to write zeroes and then use mkswap to create an empty swap partition.
$ dd -if=/dev/zero of=/path/to/file bs=512 count=1
adjust the size that you want your files to be.
sudo swapoff -v /dev/sda2 <== The swap partition
sudo dd if=/dev/zero of=/dev/sda2 bs=512 status=progress
sudo mkswap /dev/sda2 UUID=46c1a133-bfdd-4695-a484-08fcf8286896 <== The original UUID of the swap partition