Grub change loopback amount?

I’m having an issue with loopback. It looks like there is only 8. I did a search and apparently the problem is grub by default only has 8 loopback (devices?). If i look in /dev/ i see loop 0-7 so that does seem to make sense.

How do i change the amount of loopbacks?

Asked By: user4069


I’m not sure how GRUB comes into this, as you don’t explain the connection, but you can increase the number of simultaneously usable loop devices using the loop module (without a reboot).

modprobe loop max_loop=64

You can then manually make more loop devices with mknod like so:

mknod -m 660 /dev/loop8 b 7 8

Make sure the new loop device is owned by root:disk for consistency:

chown root:disk /dev/loop8

In the mknod command:

  • The major number for loop devices is 7. That’s what the 7 represents (constant for all loop devices)
  • The minor number is unique for each loop device. It starts from 0 for /dev/loop0, 1 for /dev/loop1, and so on.

The 8 represents the minor number for /dev/loop8.
So, for /dev/loop9, you would increase the minor number by one:

mknod -m 660 /dev/loop9 b 7 9

Here’s a shell command to create a large number of them at one time (starting with 10 through 254):

for i in {10..254}; do
    mknod -m 660 /dev/loop$i b 7 $i
    chown root:disk /dev/loop$i
Answered By: Chris Down
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