Questions tagged [ramdisk]

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Ubuntu 21.04 hangs at "loading initial ramdisk" after kernel update with LUKS

I've reproduced this twice from a fresh install - the setup initially works fine, but when a kernel update is applied, the system hangs on reboot. Selecting the older kernel I have available from GRUB ...
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RAMDisk disappears after random read tests

I have created 60GB RAMDisk using the command modprobe brd rd_size=62914560. It creates 16 RAMDisks and I use /dev/ram1. The linux is CentOS 7.5 with kernel version 3.10. I don't make any filesystems ...
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1 vote
1 answer
847 views

Make a temp virtual RAM disk from some RAM + some SSD

I'm in an odd situation where I have plenty of RAM sitting around (200gb extra) and ALMOST enough SSD to do a read/write intensive process. Is there any way to say "Dear System, please create a ...
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0 votes
1 answer
204 views

Allocate RAM block device faster than Linux kernel can normally allocate memory

Background I'm trying to download about 150GB to a newly-created Linux box (AWS EC2) with 100gbps network connection at full speed (12.5GB/s) or close to that. The network end is working well. However,...
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1 vote
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How to create a ramdisk during a systemd service initialization (ex. Postgresql)?

Is there any way to create a ramdisk during systemd service initialization and run some command after its creation and after the "main" service process starts? Basically what I am trying to ...
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Common Features among Multiple RAMDisks Created Using modprobe brd

I wanted to create a 60GB RAMDisk to check the read and write performance of it. Using the command modprobe brd rd_size=62914560, 16x 60GB RAMDisks have been created: /dev/ram0, /dev/ram1, ..., /dev/...
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2 answers
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Multiple Threads Cannot Access the Same RAMdisk Created by modprobe

I have created RAMdisks of 60GB using modprove brd rd_size=62914560 on CentOS 7.5. Checking the results, fdisk -l /dev/ram* shows 16 ram block devices of 60GB size (/dev/ram0, /dev/ram1, ..., /dev/...
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Why isn't a ramdisk removable?

(Inspired by https://unix.stackexchange.com/a/254254/320598) In Linux ram disks like /dev/ram0 created by the brd driver aren't removable according to /sys/block/ram0/removable, and I wonder: Why? One ...
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RAM based file system that overflows to physical disk and maintains maximum I/O performance

I have an issue that seems to hit all the restrictions I have read about regarding tmpfs. I would be very happy to hear anyone's comments on a possible solution. I have an application that generates a ...
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Limiting the resources used by a process

This is now the third time I've had this problem and had to look up how to do it with the specific caveats of my particular instance. As such I want to write a script that will go through all the ...
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5 votes
1 answer
197 views

How to deallocate Linux RAMdisk

I am having trouble to deallocate RAMdisk in Linux. I think that blockdev --flushbufs /dev/ram0 used to work in the past. But now: cat /dev/urandom > /dev/ram0 md5sum /dev/ram0 ...
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Ramdisk mounted at mnt/ramdisk goes to /run/user

To create a ramdisk (Ubuntu 18.04), I issued "sudo mkdir /mnt/ramdisk" at the Putty terminal prompt. Then I issued "mount | tail -n 1" and it returned: tmpfs on /run/user/1000 ...
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U-Boot "Wrong Ramdisk Image Format" with initramfs on BeagleBone black

I am following the book "Mastering Embedded Linux Programming - Second Edition" trying to boot up the Linux kernel mounting a ramdisk. I have U-boot 2020.01 working and the Linux kernel ...
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1 vote
1 answer
903 views

Project Quota on a live root EXT4 filesystem without live-cd

How do I accomplish setting up project quota for my live root folder being ext4 on Ubuntu 18.04? Documentation specific to project quota on the ext4 filesystem is basically non-existent and I tried ...
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-2 votes
1 answer
676 views

What happens if tmpfs reached the limit that defined in percentage

lets say we defined the following in /etc/fstab tmpfs /data tmpfs size=90% 0 0 And then we mount -a Now /data is with tmpfs What could be happens on the following scenario case that /data ...
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How to create a file-system in RAM? (a virtual disk-drive)

I'm aware of tmpfs and what I really need is a disk partition resides on RAM where I could format it with BTRFS. How can I create a raw device on RAM and format it with any regular filesystem? Or is ...
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MySQL on RAMDisk not starting

I'm trying to move all execution of the mysql program (all table data, indexes, etc) onto a RAM Disk for a performance experiment that excludes file IO from my regular SSD. I started by installing ...
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4 votes
1 answer
7k views

Where does tmpfs come from and how is it mounted

I am using a BeagleBone board with Linux. When i type command "df -h" , I see tmpfs is mounted a few times. Does this mean that all these entries get mounted at the same place, or at a ...
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0 votes
1 answer
1k views

Moving /tmp from ramdisk to other partition

Due to a deficit of RAM on Debian, I need to move /tmp to SSD drive. But I still can't figure it out, how to do that so the programs that use it will still access it under /tmp path. So basically, ...
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3 votes
1 answer
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Find size of shared memory tmpfs

When mounting a tmpfs we can pass as an option its (maximum) size and prevent the relevant fs from growing indefinitely and thus consuming all of our RAM, e.g. $ mkdir -p /tmp/shmemory $ sudo mount -...
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Is there a way to import a layout with multiple partitions into ramdisk?

I dumped the partition layout of a disk, with: sfdisk -d /dev/sda > part_table cat part_table output label: dos label-id: 0x0004bc49 device: /dev/sda unit: sectors /dev/sda1 : start= ...
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1 answer
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mv command for many nonexistent files, does it wear off the destination disk at all?

I am trying to continuously move many files (~ 10 000 each minute) from /ramdisk to normal /ssd , but not all files are there. When the mv /ramdisk/file55 /ssd/file55 fails because source is not ...
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Run Minidlna from RAMDisk

I am using Raspberry Pi to stream movies to my LAN. The movies are mounted using sshfs and streamed with MiniDLNA. Now the Pi has very slow SD-Card I/O, at iotop I can see minidlna uses <95% I/O ...
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-1 votes
1 answer
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How to sync ram disk of one server to another

I have created ram disk as /mnt/ramdisk/test in both server A and B. Where I will be writing dedicated content in each server's ram disk. Now, i want the content of ram disk in server A to sync with ...
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Inspect a Ramdrive?

I have mounted a ramdrive via /etc/fstab. And I would like to inspect the properties of the drive such as the memory policy (e.g. bind, prefer, or?) to make sure all properties are expected. How can ...
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1 vote
2 answers
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loadaddress of ramfs

I have some difficulties to make initramfs functional with SAMA5D27 SOM1 Evaluation Kit. I am trying to have a functional initramfs. I first verified that I have a functional linux when used with ...
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1 vote
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Why can't dd write to /dev/ram0 on Core Linux?

I created an ext2 file-system on /dev/ram0 ramdisk, and mounted it at /mnt/ram. mkdir /mnt/ram mkext2fs /dev/ram0 sudo mount /dev/ram0 /mnt/ram -o rw Reading from ramdisk with dd works. dd if=/dev/...
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0 votes
2 answers
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Can a script unmount the volume containing itself?

I have a computer with a hard drive mounted read-only. I am running a script from a flash drive. I would like the script to be able to unmount the flash drive, but this can't be performed as the ...
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0 votes
2 answers
28 views

Can I create a virtual network and place its configuration file outside of etc directory?

For some reasons, I need a temporary interface where its configuration file will exist only on a ram drive, so it will be removed if the power goes off. Is it possible? How?
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2 votes
1 answer
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can a full ram-disk cause swapping?

I have a application that is using /opt/otrs/var/tmp for caching a lot of temporary data. The vendor suggest that one option could be also to put this directory on a ramdisk (If you have enough RAM). ...
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5 votes
1 answer
2k views

Cannot create NFS on a tmpfs drive

OS: SLES 12.3 Running these commands: mkdir /foo/ramdisk mount -t tmpfs -o size=100m tmpfs /foo/ramdisk Creating a NFS on /foo/ramdisk produces this result when I run showmount -e <IP>: ...
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0 votes
1 answer
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Question about RAM and SWAP on Windows Host OS

i've read and appreciated the original post by Thompsonn. At work i'm forced to use Windows as the host OS (I work with and prefer Linux) because of the mandatory requirements in certain applications ...
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4 votes
2 answers
5k views

How do you create block RAM Disks on demand?

I learned that I can do modprobe brd rd_nr=1 rd_size=4585760 max_part=1 if I want to create a ram block device at /dev/ram0 but lets say I want to flush the device (to free the ram), then delete it ...
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1 vote
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Anything-sync-daemon is not making backup snapshots

I have Anything-sync-daemon ("asd") installed and minimally configured according to this page: Anything-sync-daemon - ArchWiki Running asd p gives the following output: Anything-sync-daemon v5.85 ...
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2 votes
1 answer
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Generate bootable ELF from bootloader, kernel, device tree, ramdisk

I'm new to Linux Kernel programming, and am pretty stuck with (what I think is) the last step in building my bootable image. For some background, we are trying to upload a complete OS image onto the ...
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0 votes
1 answer
485 views

Linux: How to create and attach a RamDisk without mounting it?

On Linux, how can a RAM disk be created and attached without being mounted? Moreover, how can the device name like /dev/sdb assigned to the RAM disk be found? Finally, how can the RAM disk (which is ...
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4 votes
2 answers
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How can I create an ext4 ramdisk?

First, I have create the directory that I will want to mount to. mkdir /mnt/ramdisk Now, I could easily turn this into a ramdisk using ramfs or tmpfs via mount -t tmpfs -o size=512m tmpfs /mnt/...
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-4 votes
1 answer
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If I have a RAM Disk, for what do I need system RAM

I was wondering, if I have a RAM Disk and put my whole OS onto that RAM disk, then I guess there is no use for the system RAM anymore, since fetching it from there is not faster than fetching it from ...
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1 vote
0 answers
734 views

Using compressed RAM disks for swap in FreeBSD on an early Raspberry Pi board

I have an old Raspberry Pi one model B with 256Mb RAM with FreeBSD installed (12.0-CURRENT). Since the device has so little memory, I thought I'd try to use compressed swap in RAM, in order to achieve ...
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1 vote
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Define RAM disk size of a custom built kali iso when booted live

I'm building a custom kali iso and would like to define the size of the root / (tmpfs) partition when it's booted live from an USB. Is this possible? I've got 32G of ram, and the ram disk size is 50%=...
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1 vote
1 answer
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Is there ramdrive on AWS EC2 instance by default?

I found my df command says the following: $ df Filesystem 1K-blocks Used Available Use% Mounted on udev 31428656 0 31428656 0% /dev tmpfs 6288016 9136 ...
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8 votes
3 answers
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RAM alternative to swap partion or swap file on an SSD

My Debian stretch system has a lot of RAM. Currently, it uses an encrypted swap partition on the SSD, but under normal conditions I don't ever expect lack of memory to cause it to be used. But ...
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0 votes
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moving /media mounted drives on tmpfs

I recently bought a new usb to run my linux-on-the-go system. I am aware of block limited write-cycles, so I am trying to minimize disk writes. I know that when I insert a disk, it mounts inside /...
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2 votes
0 answers
732 views

How to reserve ram for ramdisk (tmpfs) but also prevent it from swaping

My scenario: I have a server with 256GB of ram and I want to create a ram disk, with let's say a 224GB size. Now, I know that there are two main types for ramdisk - ramfs & tmpfs (taken from here):...
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1 vote
1 answer
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How to specify U-Boot not to use uramdisk

I would like to specify U-Boot not to use uramdisk to boot because my ramdisk is part of the Linux image. The problem is that even if I choose sdboot which I modified and call "bootm {linux} - {...
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Benchmark /dev/shm

I am currently developing a software that needs fast inter-process and temporary I/O communication (images as well as big hdf5 arrays). The "lifetime" of the data is different and dependent on several ...
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Can you write your whole existing filesystem to an image?

I'm reading about filesystems for embedded linux. If you're using a ramdisk, how its supposed to work is a compressed image of the filesystem is kept in the boot partition, and is copied into the root ...
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7 votes
1 answer
2k views

How to specify memory region for ramdrive

We are setting up a Linux based benchmarking cluster. Each node is going to be a headless, diskless machine, booted via tftp, the OS copied to a local ramdrive, and the same ramdrive is used as local ...
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5 votes
0 answers
2k views

Tmpfs with overflow on disk?

I'm looking for a way to have a tmpfs-like file system that can be unlimited in size, but will use a specified amount of RAM after which the "oversize" data will be stored on another disk-...
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Under guest virtual machine, Debian hangs when loading initial ramdisk

I am new to Linux, and recently installed Debian 8 to a guest virtual machine running under Virtual Box on a Windows 8 laptop (Asus x552cl). When I try boot up the Debian system, the virtual machine ...
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