How to create a single 4GB large ramdisk?

[Clemens Eisserer]

Hi,

I need a single ramdisk which is a real block device (unlike tmpfs),
so I found the ramdisk_size kernel boot parameter.
However, after invoking "MAKEDEV ram" I get hundreds of 16mb large
ramdisks, instead of a single 4GB large:

dd if=/dev/zero of=/dev/ram0 bs=1024k count=2048
dd: error writing ‘/dev/ram0’: No space left on device
17+0 records in
16+0 records out
16777216 bytes (17 MB) copied, 0.032487 s, 516 MB/s

Any idea how to get a single ramdisk instead, I am using Fedora20 on x86_64 btw.

Thank you in advance, Clemens