How come RAMdisk not visible lsblk -all ?

[joseph22]

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How come?

df            # shows RAMdisk

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How come RAMdisk not visible with 3 commands?

lsblk -all    # does not show RAMdisk, but  man lsblk  says list RAM disk devices.
lsblk -I 1    # does not show RAMdisk -I, --include <list> show only devices with specified major numbers
sudo fdisk -l # does not show RAMdisk

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man lsblk     # -a, --all  Also list empty devices and RAM disk devices.

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lsblk         # The command prints all block devices (except RAM disks) in a tree-like format by default.

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Made 1 GB RAMdisk:

sudo mkdir /mnt/ramdisk
sudo mount -t tmpfs -o rw,size=1G tmpfs /mnt/ramdisk

Verify 1 above RAMdisk:

df -h |grep -i 'ram\|size'  # verify
 
Filesystem      Size  Used Avail Use% Mounted on
tmpfs           1.0G  625M  399M  62% /mnt/ramdisk

Verify 2 above RAMdisk:

df -BG |grep --color=always -i 'sd\|nv\|blocks\|ram' # drive capacity in GB

Verify 3 above RAMdisk:

mount | tail -n 1            # verify

Verify 4 above RAMdisk:

time sudo dd if=/dev/zero of=/mnt/ramdisk/zero bs=64k count=10000
  655360000 bytes (655 MB, 625 MiB) copied, 0.119574 s, 5.5 GB/s

using
OS: Kubuntu 22.04.1 LTS x86_64
neofetch --stdout | grep 'OS:'



How come RAMdisk not visible lsblk -all ?



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[claydoh]

I can't find a reference to this at the moment, but I seem to recall that util-linux (and therefore fdisk etc) stopped reporting ramdisk as block devices years ago, for whatever reason. So lsblk can't see them.

[joseph22]

I can't find a reference to this at the moment, but I seem to recall that util-linux (and therefore fdisk etc) stopped reporting ramdisk as block devices years ago, for whatever reason. So lsblk can't see them.

Who is responsible to update
man lsblk ?

lsblk --version

lsblk from util-linux 2.37.2

man lsblk

-a, --all
Also list empty devices and RAM disk devices.

[claydoh]

Ahhh I missed 22.10

I don't know. I don't know what has changed in the the current version. Maybe you have found a bug? Or there are extra parameters to pass to view ramdisks that the documentation is not clear about.

In any case, this is an Ubuntu or util-linux related issue, not specific to Plasma or Kubuntu itself. I don't yet see anyone one else with similar complaints.

BUT:

lsblk from util-linux 2.37.2

If you are on 22.10, you should have utiil-linux 2.38-4ubuntu1
If not, this may be the problem. 2.37 is Jammy's, and if you are on Kinetic, you might have something broken here.

I know that the -a is *supposed* to show all, but this might be dependent on other support being built in to the kernel or something else, but I am not clear on this. My braine hurtz

[joseph22]

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Does anyone else have the same problem?

df          # shows ramdisk
lsblk -all  # does not show ramdisk

installed 22.10 and updated it.

dpkg -l |grep 'util-linux' |awk '{print $3}'
2.38-4ubuntu1

lsblk --version
lsblk from util-linux 2.38

neofetch --stdout | grep 'OS:'
OS: Kubuntu 22.10 x86_64

installed 25GB ramdisk1 with 3 commands:

sudo mkdir     /mnt/ramdisk1
sudo chmod 777 /mnt/ramdisk1
sudo mount -t tmpfs -o rw,size=25G tmpfs /mnt/ramdisk1

made 2 files 22GB and 1GB on ramdisk1

time sudo dd if=/dev/zero of=/mnt/ramdisk1/zero22G bs=1M count=22000
time sudo dd if=/dev/zero of=/mnt/ramdisk1/zero01G bs=1M count=1000

confirmed ramdisk1

df     |grep -i 'blocks\|ramdisk'
Filesystem      1K-blocks      Used Available Use% Mounted on
tmpfs            26214400  23552000   2662400  90% /mnt/ramdisk1

confirmed ramdisk1 using GB

df -BG |grep --color=always -i 'sd\|nv\|blocks\|ram'

Filesystem     1G-blocks  Used Available Use% Mounted on
...
tmpfs                25G   23G        3G  90% /mnt/ramdisk1

lsblk -all

does not show ramdisk.

NAME      MAJ:MIN RM   SIZE RO TYPE MOUNTPOINTS
loop0       7:0    0     4K  1 loop /snap/bare/5
loop1       7:1    0  63.2M  1 loop /snap/core20/1623
loop2       7:2    0 238.5M  1 loop /snap/firefox/1969
loop3       7:3    0 346.3M  1 loop /snap/gnome-3-38-2004/119
loop4       7:4    0  91.7M  1 loop /snap/gtk-common-themes/1535
loop5       7:5    0    48M  1 loop /snap/snapd/17336
loop6       7:6    0     0B  0 loop
loop7       7:7    0     0B  0 loop
sda         8:0    0 119.2G  0 disk
sda1        8:1    0   512M  0 part
sda2        8:2    0 118.7G  0 part /var/snap/firefox/common/host-hunspell
                                    /
sdb         8:16   0   1.4T  0 disk
sdb1        8:17   0   1.4T  0 part /media/x/s1397GB
sdc         8:32   0   1.8T  0 disk
sdd         8:48   1  28.9G  0 disk
sdd1        8:49   1     4G  0 part
sdd2        8:50   1   4.2M  0 part
sdd3        8:51   1   300K  0 part
sdd4        8:52   1  24.9G  0 part /media/x/writable
sde         8:64   1  29.2G  0 disk
sde1        8:65   1  29.2G  0 part /media/x/x_FAT_32
nvme0n1   259:0    0 465.8G  0 disk
nvme0n1p1 259:1    0   512M  0 part /boot/efi
nvme0n1p2 259:2    0 465.3G  0 part

man lsblk
-a, --all
Disable all built-in filters and
list all empty devices and
RAM disk devices too.

Does anyone else have the same problem?

df          # shows ramdisk
lsblk -all  # does not show ramdisk

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[Schwarzer Kater]

I guess that lsblk generally doesn't show tmpfs?