Questions tagged [loop-device]
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24 questions
0 votes
1 answer
2k views
Mount DD image of LVM partition
I am in a conundrum. I need to extract data from a backup image I created previously. I thought I knew enough about LVM to get by... at least until now. It seems my blunder is that I backed up an LVM ...
- 249
0 votes
1 answer
618 views
Bad performance on multiple loop devices used as file containers
Currently, I'm managing a back-up service for multiple remote servers. Backups are written trough rsync, every back-up has it's own filecontainer mounted as a loop device. The main back-up partition ...
- 183
0 votes
1 answer
7k views
losetup mounts disk image as one device. How to loopback the partitions seperately?
I have a disk image with 2 partitions. When I do #losetup -f <file> only /dev/loop0 appears. How do I make /dev/loop0p0 and /dev/loop0p1 appear? Using #parted /dev/loop0 it does show the 2 ...
- 103
0 votes
0 answers
159 views
How to require a password/key/secret supplied by human sysadmin (via an ssh login) for every mount of a LUKS-based volume?
Summary We want to support this scenario: if we sense any security threat that might expose our core data (all stored on a /home NFS mount from our NFS server), we immediately "hard" power off the ...
- 267
2 votes
2 answers
3k views
loop device does not auto detach on umount
I have a backup script in which I umount a squashfs file, I do backup then mount it back again. A simplified version of the script is: umount /home/backup/auto/mnt/os mksquashfs /src-dir /home/backup/...
- 298
7 votes
2 answers
2k views
ZFS - Use a file as l2arc cache
I have a CentOS server that is using zfs to manage a big, slow, network attached volume. We read quite a lot from this volume, hence I would like to optimize the read performances. The idea is ...
- 183
2 votes
3 answers
2k views
Can I create a compressed loop-device filesystem that can expand to fit the data size?
I have large numbers of small log files that are essentially write-only, unless I have to look at them for some reason. Right now, they accumulate in day-specific subdirectories in a logging folder (e....
- 1,135
4 votes
1 answer
3k views
How can I give access to loopback devices which are created dynamically to a Docker container?
I have a small Docker container from which I can access /dev/loop0. For this I've added to docker run: --device=/dev/loop-control:/dev/loop-control \ --device=/dev/loop0:/dev/loop0 \ On this loopback ...
- 153
0 votes
4 answers
677 views
enabling Spanning-Tree or not
do you think is wise or stupid keeping the rapid spanning tree enabled for just two switches in this image? https://i.sstatic.net/GIG0i.jpg As you can see the switches are not redundant each other ...
- 21
3 votes
2 answers
440 views
No write failure on an over-allocated sparse file
I've been working with sparse files in order to replicate Linux fs permissions on a Windows samba mount an idea from here: https://www.thanassis.space/backup.html. While testing sparse files though, ...
- 33
0 votes
1 answer
2k views
Cannot mount manually docker's loop device
I'm learning how to work with loop devices and noticed that Docker uses them by default on CentOS. I can mount loop devices that I created, but when I try to mount Docker's devices I get error: $ ...
1 vote
0 answers
235 views
A looped hub connected to a switch
---- We don't want to block the use of Hubs --- If two switches are connected to each other via a hub, STP detects and blocks alternate link (if available). But if a hub is connected to even one (...
- 11
2 votes
1 answer
4k views
Link Aggregation with 3 switches
I am new in networking. Sorry for my ignorance. I have three switches. Switch 1 has 4 ports. Two of them connected to switch 2. And the other two ports are connected to switch 3. All these four ...
- 23
1 vote
1 answer
727 views
kpartx device to image mapping
I am using kpartx to map the paritions of an image file to device mapper. kpartx maps the image to one of the free loop devices, for example, /dev/loop0 Is there a way to query what image is mapped ...
- 163
6 votes
1 answer
14k views
Loop back mount a VMDK flat image on a Linux Box
I am trying to loop mount a VMDK flat image generated by VMware fusion. The VMDK file has the -flat extension. I am trying to use kpartx kpartx -av /path/to /my/vmdk but I get llseek error device-...
- 163
0 votes
2 answers
2k views
nfs, mounted loop devices
I'm usign a Debian server (Jessie) as an NFS server. All exported NFS-shares are mounted filesystems using loop devices. They are mounted in the fstab without any special options & the mountpoints ...
29 votes
2 answers
64k views
loop device in a Linux container?
I'm attempting to use a loop device inside a container, to mount some image file: > sudo losetup /dev/loop0 test.img losetup: /dev/loop0: failed to set up loop device: No such file or directory /...
- 1,277
1 vote
2 answers
2k views
Loop device going into Readonly Mode
We are using a network Samba drive for Backup on our Linux Server. In order to store permissions (Samba does not support this), we have created a loop device to a large file (50GB) on the network ...
- 143
5 votes
3 answers
6k views
Find out which loop device is behind a dev mapper block device
I'm using cryptsetup with loopback devices. I'm looking for a way, given a device mapping, to identify which loopback device is used by this device. i.e. get /dev/loop1 as a result of an operation on /...
- 181
-1 votes
1 answer
601 views
Storage virtual machine. LVM or loop devices? [closed]
Actual situation: I'm the administrator of a virtual machine. The virtual machine is a Debian. This machine will be mainly a storage machine with different services (svn, ftp... ), and a webserver. ...
- 3
1 vote
1 answer
1k views
poor performance with vmdk mounted as loop device even after conversion to raw
Edit 13/12/12 - At this stage it would appear to be related to Western Digital (and possibly others) Advanced Format 4K block sizes. This link goes some way into describing the issue, however the ...
- 41
3 votes
1 answer
4k views
Cannot read device /dev/loop0
I'm trying to create a crypted drive on my loop0 device. For this command /sbin/cryptsetup create cryptedDrive /dev/loop0 I'm getting the following error Cannot read device /dev/loop0 Here's my ...
- 133
3 votes
1 answer
247 views
Why make random file for loopback device for encrypted file system?
I have read a few tutorials on setting up an encrypted file system using cryptsetup. They all start with the following creation of a random file dd if=/dev/urandom of=/etc/cryptfile bs=1M count=10 ...
- 153
1 vote
1 answer
2k views
Why does this loopback device creation malfunction?
The stackoverflow people thought this was more appropriate here, I put it there as it is part of a program but I can see their POV, so here it is: At the bottom of the code you can see it failing. In ...
- 111