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Questions tagged [device-mapper]

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LUKS2 - RAID0 - NVME : alignment issue

I have trouble while in top of this stack bellow: mkfs.ext4 /dev/mapper/raid0luks2 /dev/mapper/raid0luks2 alignement is offset by 147456 bytes This may result in very poor performance (re-) ...
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1answer
18 views

Prevent LVM creating dm-X devices

Was wondering if it's possible to stop LVM on RHEL7 creating symlinks of /dev/dm-X to rootvg? I'm using my RHEL hosts to connect to SAN LUNs, and prefer to have /dev/dm-X only mapped to multipath ...
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1answer
858 views

Create block device link to target /dev/mapper

Setting up a Full Disk Encryption on Ubuntu derived distro's is easy, because Ubuntu's installer simply provides access to all available partitions on all available disks from within the partitining ...
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1answer
99 views

Disk UUID from blkid output disappears

I'm experiencing a weird situation on RHEL-7. I create a device mapper (crypt) over a disk partition and then copy data (bytes) from disk partition to mapper. The blkid output has two entries for the ...
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1answer
813 views

udev rules for device mapper when lvm volumes are activated

I currently have a couple of custom udev rules for activating LVM volumes when raid volumes become available that look like this: KERNEL=="md0", RUN+="/sbin/pvscan --cache -aay" KERNEL=="md1", RUN+="/...
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1answer
372 views

A scheme for swap space on a USB

I have recently bought a USB flash drive that I am going to use solely for swap partitions. I understand that swap files on flash media are likely to use up the number of write cycles rather quickly, ...
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1answer
108 views

Is it possible to test dm's multipath driver without a physical multipath device?

I need to test a scenario that one of our customers has run across using a multipath device. I was hoping to be able to set up a device mapper using the multipath driver pointing to a loop or physical ...
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1answer
365 views

How do I remove a delay created using dm-delay?

As part of testing my application, I wanted to see what would happen on hard-disk slow down or failure. I added a 500ms delay using dmsetup create delayed. I'm not very familiar with device mapper, ...
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How to disable “device mapper” warnings in fedora

Mine is an x86 based embedded platform.. Running completely out of NFS. I recently ported fc23 onto it... But been getting this warning message every time I give the reboot command.. [ OK ] Stopped ...
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1answer
237 views

Assuming you can't directly boot into a linux system, how do you make the bootstrap?

What are the actual steps, assuming you had a set of c header files that described the memory mapped devices in your system, to make the initial running kernel? I know everyone just boots off a live ...
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1answer
2k views

How can I fix my rt (right trigger) bottom on pso2 (Phantasy Star Online 2)

What happened was I was starting up pso2 and everything went okay EXCEPT for one thing. When I tried to get my items in my inventory, it highlighted everything and I can't get the item that I want. ...
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1answer
1k views

%T specifier in printf option of `stat` command

I want to know what is %T specifier in stat printf option and how it gets the file descriptor value ie., fd,1 is printed by using the below command. command is $> echo `stat -L /dev/mapper/...
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1answer
488 views

How can I export a /dev/mapper mounted filesystem via NFS?

I have a server "pr-cl-n1" that mounts /usr via /dev/mapper like this: # mount [...] /dev/mapper/pr--cl--n1-usr on /usr type ext3 (rw,relatime,errors=continue,barrier=1,data=ordered) The root of the ...
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1answer
371 views

Can I make a encrypted image by using openssl encrypt tools instead of dmsetup?

Generally, I can create a encrypted ext4 image by do this: fallocate -l 6553600 encrypt.img losetup -f encrypt.img dmsetup create encrypt_disk --table "0 12800 crypt aes 32BYTEKEY 0 /dev/loop0 0" ...
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1answer
2k views

dmsetup status fields explained?

I am not new to linux, but I am new to the underlying guts of it, and I don't know anything about LVM or device-mapper. I'm trying to troubleshoot a livecd mounting its live-rw (dm-0) file system as ...
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2answers
57 views

Is there an easy way to retrieve the link speed of network devices?

We have a mix of 100 and 1000mbps cabling in this office with cabling that ranges from ancient home-made cat5 to brand new cat6, and a mish-mash of semi-accessible switches and network segments that ...
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1k views

Why do loop devices sometimes refuse to go away?

I regularly mount the partitions inside an image file as loop devices: sudo kpartx -a test.img That creates loop devices such as /dev/mapper/loop0p1 /dev/mapper/loop0p2 When I'm done, I get rid of ...
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1answer
44 views

Regard a folder as a normal USB stick storage

In Ubuntu, it is known that one can install a Ubuntu iso file to a USB stick using the below command: dd if=./Ubuntu.iso of=/dev/sdb where /mnt/sdb refers to a USB stick plugged to a Linux machine. ...
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1answer
2k views

How to Create Virtual Block Devices

I want to create multiple virtual block devices like /dev/sda and then use them to create an md device for test purpose. I have mounted my root filesystem on /dev/sda1 and don't have extra space to ...
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3answers
1k views

Any way to make partitioning tools see kpartx-created devices?

I have a dd'ed disk image file with me. I can use a tool like kpartx to create a device-mapper device from this disk image file. But partitioning programs like gparted and fdisk don't list my ...
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1answer
57 views

How to autodetect device name in Linux

I have an encrypted USB dongue with cryptosetup, to mount it I have to execute a script that has hardcoded (or admits it as a parameter) the device name of that dongue that previously you had to ...
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0answers
1k views

Udev rule for changing owner of Linux LVM device nodes

I'm having some trouble changing the owner of a Linux LVM logical volume on my Debian wheezy system. I added the following udev rule to both the initramfs and the real root file system: SUBSYSTEM=="...
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608 views

Moxa - NPort 5110 as HTTP Server or similar

I have a NPort 5110 Serial Device Server connecting our Automation Control Box to the LAN so we can communicate with it from a non-local pc via mapped com port. (if you are unfamiliar with the device ...
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4answers
7k views

TRIM support via dm-crypt/device-mapper

Getting a new laptop with SSD tomorrow. I need to know about the current status of dm-crypt and TRIM. I have seen several conflicting reports and most activity around this question seems to be > 1 ...
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0answers
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How to mount USB disk with LVM/LUKS crypted volumes on a Mac? [duplicate]

Possible Duplicate: How to mount an encrypted ext3 filesystem under OS X? I have a USB disk that I've partitioned with LVM and encrypted some of the volumes with LUKS. This is all Linux/Device ...
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6answers
87 views

Is there some utility that will allow me to see all devices physically connected to my laptop, regardless of whether they have a driver or not?

Upgraded Vista to 7 last day and my wireless laptop adapter is behaving funny. First it was killing me with resource conflict issues, but I just did a fresh Win 7 installation and the thing just does ...
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0answers
773 views

How to disable Device mapper package from kickstart?

Can anyone tell me how to disable/exclude Device mapper package from kickstart file.