Linux Mount Loop

A mount point – is a directory (typically an empty folder) from which the content of an ISO disc image will be accessible. I n this article we are going to learn How to mount and unmount Linux file system. img /mnt/DEMO/ ls -l /mnt/DEMO/ You can now look at the /mnt/DEMO subdirectory for the contents of the demo. UUID is a property of the disk partition itself. First,create a directory which you want to mount ISO images to by running following command in terminal: sudo mkdir /media/ISOimage. A mount point - is a directory (typically an empty folder) from which the content of an ISO disc image will be accessible. Orange Box Ceo 6,780,709 views. ro - Mount read-only. tmpfs is supported by the Linux kernel from version 2. type helpers. It is basically an application that allows you to run Desktop Linux distributions like Ubuntu, Debian, BackTrack, … on your Android device. To install elementary on a machine without a DVD Drive and where you are unable to boot from a USB memory stick but where you do have access to grub. Use mount Command. Description of problem: "mount-loop" fails to mount a filesystem image. Linux File Systems (mkfs, mount, fstab) This article provides an introduction to Linux file systems, with specific reference to the information needed for the RHCSA EX200 and RHCE EX300 certification exams. Set up the loop device. -d, --detach-loop When the unmounted device was a loop device, also free this loop device. Many mount operations require root (su -) or superuser (sudo) permission. Onward! Before we start, it should be noted that you don’t want to do this while your disk image is already. Sure, you can run most applications natively in Windows - but sometimes it's just easier to run it in a Linux container for […]. To do so, you must have an ISO file (I used ubuntu-16. 3 r119552, attempting to mount an EXT4 partition image on the Linux guest stored in a shared folder on the Windows host fails with "mount: can't read superblock on /dev/loop0". img /mnt/rabbit That mounted the first partition, the ‘boot’ partition, but this didn’t have the data on it that I was looking for. How do I mount an LVM volume/partition in Linux to access my data? Can you tell me the command to mount LVM partition in Linux? Introduction: LVM is an acronym for Logical Volume Manager. The first operation may be performed by programs such as losetup [9] in Linux , or lofiadm [10] in SunOS. ubifs -m 2048 -e 129024 -c 677 -r /path/to/rootfs ubifs. mount -t iso9660 /dev/dvd-rw /media/ Let us see what this command means. I have some data on second SATA hard disk created by Fedora Linux installer with some data. Current distros include Ubuntu, Debian, Fedora, ArchLinux, Kali Linux, openSUSE and more coming. Once you create a partition, you’ll use mkfs command to create ext2, ext3, or ext4 partition. Loop devices are pseudo devices available under linux commonly found under /dev/ with the name of loopN where N is a number like 0,1,2,3,4 etc. x) and /dev (when using DevFS). iso /media/iso -t udf -o loop Mount an ISO Image in Gnome. Learn how to mount ISO disk image in Linux. This article describes the if statement in Linux and how you can use the this statement to carry out certain commands based on testing a condition. It triggers the lock on the mount until "nfs-kernel-server" is stopped. Hi Matthew, The mnt directory is there of course, but the mmcblk0 doesn't exist (likewise for mmcblk0 partition 1). The kpartx tool makes this easier. We're using loop to force mount to use a loop device file to connect to our ISO image. If no explicit loop device is mentioned (but just an option '-o loop' is given), then mount will try to find some unused loop device and use that. Had the same issue! Seems like you have to loop mount into the exported directory (subdirectory of the exported directory in my case) and browse this mount from the remote host. Linux supports a special block device called the loop device, which maps a normal file onto a virtual block device. Mounting a loop device. ARE YOU LOOKING FOR A LINUX JOB?. The first command allows us to recognize our disk image as a virtual (or loop) device. For option 2; to mount the file and the filesystem on it, use the mount command. #mount -o loop,ro,offset=32256 hda. 30 did not have this issue as far as I can remember. 10 AMD64 On 5. ) If you do try to 'modprobe loop', you get the following;. img (from a default RHEL3 kernel):. There are two ways available in linux by which we can mount the file system i. Had the same issue! Seems like you have to loop mount into the exported directory (subdirectory of the exported directory in my case) and browse this mount from the remote host. Start by creating the mount point, it can be any location you want:. defaults - Use default settings. But it is a useful technique. Mounting a disk image using the loop device. The loop device is a special pseudo-device that makes a file accessible as a block device. Solution from ArchWiki: udisks - Mount loop devices. The mount command automatically creates a loop device from a regular file if a filesystem type is not specified or the filesystem is known for libblkid, for example: mount /tmp/disk. Actual Result mount: Could not find any loop device. Brought to you by the LinuxonAndroid project the app is designed to allow you to install a full Linux distro without touching your Android install. iso /media/iso -t udf -o loop Mount an ISO Image in Gnome. Mounting a raw partition file made with dd or dd_rescue in Linux 2010-12-15. In order to find the device that corresponds to your FFS partition, run: sfdisk -l; Disk /dev/hda: 155061 cylinders, 16 heads, 63 sectors/track Warning: extended partition does not start at a cylinder boundary. Since util-linux v2. Thanks for contributing an answer to Stack Overflow! Please be sure to answer the question. For example : file :demo. to transfer files. iso ISO image) and mount point directory to mount or extract ISO files. BackTrack 5. Re: [SOLVED] Mount: failed to setup loop device More likely you did a kernel upgrade and haven't rebooted yet. Current distros include Ubuntu, Debian, Fedora, ArchLinux, Kali Linux, openSUSE and more coming. If you have downloaded a *. You can also free a loop device by. If this is your first visit, be sure to check out the FAQ by clicking the link above. When mounting ISO images of DVDs, you might have to use the UDF type instead of ISO. -d,--detach-loop When the unmounted device was a loop device, also free this loop device. Question: I heard good things about XFS, and would like to create an XFS file system on my disk partition. img /mnt/DEMO/ ls -l /mnt/DEMO/ You can now look at the /mnt/DEMO subdirectory for the contents of the demo. Download RHEL 7. To mount the ISO image file. It is basically an application that allows you to run Desktop Linux distributions like Ubuntu, Debian, BackTrack, … on your Android device. LVM is a device. For example, the device may be the unencrypted version of an encrypted file. Linux supports a special block device called the loop device, which maps a normal file onto a virtual block device. disk drive access In GNU/Linux we "mount" a drive to access the files on it. ubi is the name of the rootfs image that will be created. Consider a situation where you need to clone one drive to another with dd or when a hard drive is failing badly and you use dd_rescue to salvage whatever data you can. mount a file system All files accessible in a Unix system are arranged in one big tree, the file hierarchy, rooted at /. Once you create a partition, you'll use mkfs command to create ext2, ext3, or ext4 partition. It can be used to mount any thing from a Samba mount to a ISO image file. It is basically an application that allows you to run Desktop Linux distributions like Ubuntu, Debian, BackTrack, … on your Android device. dd — Copy and convert the encoding of files. dislocker is a free utility, which can be used to mount BitLocker encrypted volumes on Linux. Re: [SOLVED] Mount: failed to setup loop device More likely you did a kernel upgrade and haven't rebooted yet. Loop devices are pseudo devices available under linux commonly found under /dev/ with the name of loopN where N is a number like 0,1,2,3,4 etc. Is there a command in Linux to list all mount points for a given environment? and also can use mount command in any of them or mount -l in linux. The Linux boot process has six states of operation of which "0" is the shutdown state and "3" and above are fully operational with all essential processes running for user interaction. These files can be spread out over several devices. We can mount an ISO file using the loop device. A loop device is a pseudo-device that is able to redirect and transform data that goes through its loop and which is used mainly used for encrypting filesystems. 3 r119552, attempting to mount an EXT4 partition image on the Linux guest stored in a shared folder on the Windows host fails with "mount: can't read superblock on /dev/loop0". Note: remember to mount this as "read only", i. user - Permit any user to mount the filesystem. How to Create, configure and mount a new Linux file system 1) Create one or more partitions using fdisk: fdisk /dev/sdb N (new partition) p (primary partition) Accept default initial and end blocks if you want to create a single partiton with the whole disk. It adds support for transparently decompressed, read-only block devices. The management user interface for the loop device is losetup, which is part of the package util-linux. -r there for read only option. Mounting a file containing a filesystem via such a loop mount makes the files within that filesystem accessible. This is done using the losetup command from the util-linux package. If you don't want to waste your CD's/DVD's here is the simple possible solutions using these tips you can mount and unmount ISO images without burning them. Updated August 14, 2019 120. $ sudo mount -ro loop /images/partition. mount -t ext2 /dev/loop0 /mnt umount /dev/loop0 losetup -d /dev/loop0. /dev/sda1 only), one can use the combination of "ro" and "loop" mount options for the mount command from util-linux (command line example: mount -o ro,loop /dev/sda1 /mnt/sda1/) – both options used together tell the mount command to create a loop device for a specified block device. This recipe describes the command used to mount an ISO image on a Linux system. Linux supports a special block device called the loop device, which maps a normal file onto a virtual block device. If only the loopdev argument is given, the status of the corresponding loop device is shown. A swap partition can be created with most GNU/Linux partitioning tools. Your Linux system should already have the tools required to do this without the need for virtual machine. Loop Devices. defaults - Use default settings. img /mnt/part1 sudo mount -t ntfs-3g -o loop ~/mom/part2. Thanks for contributing an answer to Stack Overflow! Please be sure to answer the question. Swap partitions are typically designated as type 82. Download RHEL 7. Below is the command to mount a iso image file. In Windows we have drive mapping. RETURN CODES top. But it is a useful technique. img is a temp file you can delete once you are done, and your_erootfs. DOS and Linux will interpret the contents differently. img /mnt mount -t ext3 /tmp/disk. type helpers. I'm using Windows 10's Ubuntu Bash shell. Therefore, this action is not supported because Red Hat cannot guarantee consistent performance and predictable behavior for ext3 file systems in this way. Since util-linux v2. mount -t iso9660 /dev/dvdrom /media/ If your device is a DVD writer use below command. sudo mount filename. This allows for the file to be used as a "virtual file system" inside another file. These storage devices are available as device files such as /dev/device_name. Mounting a loop device. It's specifically meant for a use like your example, where you can mount a file containing a CD image and interact with the filesystem in it as if it were burned to a CD and placed in your drive. Even though it is possible to use any partition type as swap, it is recommended to use type 82 in most cases since systemd will automatically detect it and mount it (see below). mount -t ext2 /dev/loop0 /mnt umount /dev/loop0 losetup -d /dev/loop0. They appear in the mount point directory using following Linux commands. The following are some of the available options for the mount command: auto: Allows the file system to be mounted automatically by using the mount -a command; loop: Mounts the image as a loop device. (of course, there should be a directory like this ;) Unfortunately, you must be root to do so - and the Image is only available to the root user. The Linux mount command is used to mount USBs, DVDs, SD cards, and other types of storage devices on a computer running the Linux operating system. mount -o loop とか普段なんとなくつかっているがまとめ。 ループバックデバイス(Loopback device)とは 一般的なファイルを、あたかもハードディスクなどのブロック型デバイスであるかのように扱うための機能。. Mount CD / DVD. Bash on Windows 10, no loop devices loop devices at all or is there a solution for mounting an image as a loop device? Loop devices are part of the Linux. For various reasons,you may want to use ISO images without burning them,and you just need to mount them in a easy way. iso /mnt/test. Even though it is possible to use any partition type as swap, it is recommended to use type 82 in most cases since systemd will automatically detect it and mount it (see below). mkfs — Build a Linux file system, usually a hard disk partition. 30 did not have this issue as far as I can remember. This desktop is an older computer so it's BIOS all the way, and I know the difference between BIOS and EUFI, and yes it is a dual boot, (now becoming triple boot) as I have Windows 7 Pro, Xubuntu 16. /mount_ISO_repo umount # to un mount the repo The Debian offline repository script. iso images to CD’s or DVD’s all the time, under Linux you can mount the. The call is mount --bind olddir newdir or shortoption mount -B olddir newdir or fstab entry is: /olddir /newdir none bind After this call the same contents is accessible in two places. Once you create a partition, you’ll use mkfs command to create ext2, ext3, or ext4 partition. mount is the command to mount devices files etc in a Linux/Unix box. losetup is used to associate loop devices with regular files or block devices, to detach loop devices and to query the status of a loop device. A representative example in BASH is as follows to display multiplication table with for loop (multiplication. The mount command in Linux is a very powerful command. 16-xenU) can cause an interminable loop condition at startup. Resize loop device: losetup -c loopdev Description. What Are Shell Script Variables? A variable in a shell script is a means of referencing a numeric or character value. These files can be spread out over several devices. although mount said it was. nslookup (name server lookup) is a tool used to perform DNS lookups in Linux. sudo mount -t iso9660 -o loop TinyCore-current. A hard disk image contains an MBR, then a number of partitions, but the 'mount' instruction in Linux works with disk partitions, not full disks. With Linux, Disk Images are mounted as loop devices, so the appropriate command would look like this::~$ mount -t hfs -o loop myImage. Bug 1011907 - mount-loop failed to setup loop device: No such file or directory. How to Mount an ISO Image. If we need it we can create an empty image and mount it using linux’s loop devices. Use umount to unmount a device / partition by specifying the directory where it has been mounted. If I were able to mount the vmdk file just like qemu's raw file under /media/vmware, I would be able to use it as a disk in my ubuntu, add remove files, copy and move stuff etc. mount a file system All files accessible in a Unix system are arranged in one big tree, the file hierarchy, rooted at /. You can also free a loop device by. Active I'm attempting to use a loop device inside a container, to mount some image file:. xda-developers Ubuntu Touch Ubuntu Touch Q&A, Help & Troubleshooting [Q] Error: Unable to create loop device! by rohitjan5 XDA Developers was founded by developers, for developers. Many mount operations require root (su -) or superuser (sudo) permission. mount -o loop,ro /media/dis1. You can now inspect the Jetson's filesystem in /mnt and make edits, perform cross-compiling, ect. other devices/things, Skill Level: Easy. With the advent of Windows Subsystem for Linux – or WSL – it’s become very easy for developers to run Windows 10 on the desktop and the applications they develop on Linux. Mount ISO/DVD. Loop devices are often used for CD ISO images and floppy disc images. The first command allows us to recognize our disk image as a virtual (or loop) device. In Linux, there are lots of others tools like ncdu, crusader, KDiskFree, Gnome Disk utility to monitor the disk usage. Loop Devices. When we install new hard disk into our Linux system, typically we use utilities such as fdisk or parted to create partitions. 0 it is possible to remount part of the file hierarchy somewhere else. For instance, root=/dev/hda1. Description of problem: "mount-loop" fails to mount a filesystem image. In Linux you can always mount a drive, or LVM LV, or SSH SFS share easily and run the mount command and see where everything is coming from. That's what this part of the guide is going to focus on. img (from a default RHEL3 kernel):. iso ~/iso-mount. In these cases, my technique. There is no physical limitation preventing mounting to any other directory on a drive. Modify the /etc/fstab or startup scripts of the target system to mount the squashd file system when you need it If you create a root file system out of a running Linux system, use the -e option for mksquashfs to exclude all pseudo-filesystems such as /proc, /sys (on linux kernels after 2. He is the author of Linux Hardening in Hostile Networks, DevOps Troubleshooting, The Official Ubuntu Server Book, Knoppix Hacks, Knoppix Pocket Reference, Linux Multimedia Hacks and Ubuntu Hacks, and also a contributor to a number of other O'Reilly books. Because we need to use sudo you’ll need to enter your password. To run Disk Mount, open a command terminal on a Linux host. We can not mount more than these number. You need to modify or maintain it in the way you. : $ mount -t ubifs /dev/ubi0_0 /mnt/ubifs will mount UBIFS to UBI volume 0 on UBI device 0. Autofs also referred as Automount is a nice feature in linux used to mount the filesystems automatically on user's demand. elementary OS. The for loop executes a sequence of commands for each member in a list of items. Linux supports a special block device called the loop device, which maps a normal file onto a virtual block device. To mount a SquashFS, use the mount command's -o loop option with escalated OverlayFS — an in-kernel attempt at providing union file system capabilities on Linux. Unix is also an operating system like Linux. HUGE flaw in linux file system. The "-o remount" option will make Linux try to remount the. This automatically implies noexec, nosuid,nodev unless overridden. mkfs — Build a Linux file system, usually a hard disk partition. The good news is that there is a way to work around this issue using a free Linux tool called Dislocker. A “file” is just a set of bytes with a name. Unless the storage device is mounted to the tree structure, the user can't open any of the files on the computer. Mounting a disk image using the loop device. If you are using systemd, you can take the same script, and put it somewhere else like /usr/lib/systemd/scripts, and remove the line reading "add_hook sysinit_premount do_loop", and just change it to "do_loop". Install kpartx sudo apt install kpartx Create an image file from an SD card sudo umount /dev/sdf1 sudo umount /dev/sdf2 sudo dd status=progress if=/dev/sdf of=2017-04-10-gateway-build. Depending on your distribution, you might be able to work with them in a purely graphical environment. Question: I heard good things about XFS, and would like to create an XFS file system on my disk partition. This is done using the losetup command from the util-linux package. Therefore, this action is not supported because Red Hat cannot guarantee consistent performance and predictable behavior for ext3 file systems in this way. This situation might not affect everyone, but it struck me today and left me scratching my head. Loop Devices. For details, see #Usage below, or view the manual page by running man 5 auto. Our Linux tutorial is designed for beginners and professionals. When the mount command is run, it reads the content of the /etc/fstab configuration file to see if the given file system is listed. The few alternatives left either depend on VMware Tools being installed or have networking up and running. Host: Windows 10 Enterprise v1709 AMD64 Guest: Xubuntu 17. Note: If /mnt/data is being mounted in /etc/fstab, comment it out since we are having to mount it early to setup loop devices. Whenever I restart my computer I see that the loop device is gone. mount -o loop /location/of/file. It adds support for transparently decompressed, read-only block devices. You can make use of some commands to attach an ISO image first with the loop device and then mount the loop device like you do mount any other device in your computer. The good news is that there is a way to work around this issue using a free Linux tool called Dislocker. img /mnt/DEMO/ ls -l /mnt/DEMO/ You can now look at the /mnt/DEMO subdirectory for the contents of the demo. This is also a default setting. rw - Mount read-write. If you have it on your system you can use it to flash the UBI image to the device. Loop devices are often used for CD ISO images and floppy disc images. Once you create a partition, you'll use mkfs command to create ext2, ext3, or ext4 partition. Unix is also an operating system like Linux. fc6) with small /tmp partition (it happens that it is 100% full). Below is the command to mount a iso image file. img /mnt/part1 sudo mount -t ntfs-3g -o loop ~/mom/part2. But when I found where are my loop devices by searching for 'loop' using xplore, I found there are files loop0 to loop7 in '/dev/block/'. We can quickly and easily mount, not just ISO images, but even images of disks with partitions. Sometimes you might need to run some command from the Linux command line and repeat it several times. 0 it is possible to remount part of the file hierarchy somewhere else. Mount is to access a filesystem in Linux. Since util-linux v2. How to mount CD/DVD ROM on RHEL 7 Linux After the reboot of your RHEL 7 Linux, the system will mount CD/DVD ROM automatically. Use of these commands requires Root privileges. 04, and now Linux Mint 18 xfce 32bit. To do so, you must have an ISO file (I used ubuntu-16. The bind mounts. Regression/quality control testing would have caught this, but the developers usually just break things and wait for people. There were a ton of issues along the way so I tried to follow the instructions from a. mount -o loop demo. If no explicit loop device is mentioned (but just an option '-o loop' is given), then mount will try to find some unused loop device and use that. Is there a command in Linux to list all mount points for a given environment? and also can use mount command in any of them or mount -l in linux. nouser - Only permit root to mount the filesystem. 01 version of the Arch iso. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Host: Windows 10 Enterprise v1709 AMD64 Guest: Xubuntu 17. mkfs — Build a Linux file system, usually a hard disk partition. mount root. Compilation of commands to be able to mount or unmount a partition in Linux systems in a simple way. It maps the C drive fine as /mnt/c. To mount an ISO image use the following command. Mount! mount /dev/loop0 /mnt -t msdos -o "fat=12" Unmount umount /mnt Destroy loopback device losetup -d /dev/loop0 Hard Disk Images. Finding a file in a Linux system can be difficult if you don't know how. Re: [SOLVED] Mount: failed to setup loop device More likely you did a kernel upgrade and haven't rebooted yet. How to mount an ISO image on Linux Posted in Linux/Unix/BSD - Last updated Feb. rw - Mount read-write. How to Create, configure and mount a new Linux file system 1) Create one or more partitions using fdisk: fdisk /dev/sdb N (new partition) p (primary partition) Accept default initial and end blocks if you want to create a single partiton with the whole disk. ISO Image file is like Container which contains all required materials or in simple word its an Screw Driver box which contains all different shape of bit's for different Screws, Like that ISO Image file is an archive of files and directories like tar in Linux, which may contains video/Audio files, Operating System Supporting files and. Consider a situation where you need to clone one drive to another with dd or when a hard drive is failing badly and you use dd_rescue to salvage whatever data you can. So in other words we can mount total 8 iso/img files in Linux at a time. They appear in the mount point directory using following Linux commands. The following "block device encryption" solutions are available in Arch Linux: loop-AES loop-AES is a descendant of cryptoloop and is a secure and fast solution to system encryption. The Linux mount command is used to mount USBs, DVDs, SD cards, and other types of storage devices on a computer running the Linux operating system. Bug 1011907 - mount-loop failed to setup loop device: No such file or directory. type helpers. You can use Dislocker to decrypt and mount a BitLocker-encrypted partition so that you can access it while you're running Linux. 1 on the computer, it should work on newer versions of Ubuntu too. The first operation may be performed by programs such as losetup [9] in Linux , or lofiadm [10] in SunOS. This situation might not affect everyone, but it struck me today and left me scratching my head. It's possible to create floppy disk images (IMG files) from withing Linux using native Linux utilities. When I try to run the x86_64 version I get the errors in the title. I started a new fresh PI installation, the first step is a format of the exist OVA installation (including the Linux OS) and after it the PI installing starts over. Hi Matthew, The mnt directory is there of course, but the mmcblk0 doesn't exist (likewise for mmcblk0 partition 1). To mounting an ISO image on Linux (RedHat, CentOS, Fedora or Ubuntu), you must be logged in as "root" user or switch to "sudo" and run the following commands from a terminal to create a mount point. 29 mount command re-uses the loop device rather than initialize a new device if the same backing file is already used for some loop device with. If you are using desktop manager, you will most likely be able to use it to mount USB drive for you. It is basically an application that allows you to run Desktop Linux distributions like Ubuntu, Debian, BackTrack, … on your Android device. LVM is a device. Lets try to mount partition number 3. The -t (type) option tells mount what type of file system we are mounting. losetup is used to associate loop devices with regular files or block devices, to detach loop devices and to query the status of a loop device. Loop Devices. So in other words we can mount total 8 iso/img files in Linux at a time. This is the same as above just that the file is compressed (with gzip). 4 iso and mount the same. If you have tried to configure virtualization system asking more loops to run in the server, we can build that loops in CentOS-6/RHEL-6 and CentOS-5/RHEL-5,. "Recovering a failed software_RAID" is safe to do as it does not make any changes to the RAID - except in the final stage. The "mount" command is used to mount a filesystem or storage device while "unmount" is the opposite. Most of the. This file will be created/updated during the system installation. How do I mount UBIFS? The modern way of mounting UBIFS is mounting UBI volume character device nodes, e. img /mnt mount -t ext3 /tmp/disk. It consists of three parts: Kernal, Shell and Programs. How to Mount an ISO Image. sudo mount -t iso9660 -o loop TinyCore-current. My brother has a habit of saving DVD films as a image file. Depending on your distribution, you might be able to work with them in a purely graphical environment. Please note that a loop device is a pseudo-device which will make an iso file accessible to the user a block device. mount -o loop demo. How do I make sure that a loopback device is permanently stored?. Are loop devices on Linux that are created with losetup supposed to be permanent? This does not seem to be the case for me. For example, to mount the first partition of the disk image: kpartx -a -v myimage. There is a simple way to write a command once and have it executed N times using Bash loop FOR. org, a friendly and active Linux Community. Learn how to mount ISO disk image in Linux. Don’t believe the hype! It is entirely possible to mount a VirtualBox VDI image, just like a loopback filesystem… all you need are the right tools and know-how. To specify mount options, use the -o flag followed by a comma-separated string of options. In certain situations, system administrators will need to mount cdrom containing the installer or data on linux CentOS or RHEL. Use of these commands requires Root privileges. ISO image file mounts using loop device and iso9660 filesystem type enabling user to access data within as a normal mount point. If you are not so unwise as to make /etc/mtab a symbolic link to /proc/mounts then any loop device allocated by mount will be freed by umount. I'd imagine one can mount it from Linux via loop device (assuming you have support for that filesystem). Neither of these fields may contain spaces. mount -o loop demo. In these cases, my technique.