a better ramdisk solution?

fmillion · 05-30-2008, 02:30 AM

Hey guys,
Is there a better solution for ramdisk block devices? Rebooting to change the size of /dev/ramXX seems inconvenient at best. Tmpfs isn't quite suitable for my project because I want to work with actual "real" filesystems (think creating a real FAT32 or ext3 filesystem on a block device". Is there any kind of kernel module or some sort of command to resize the kernel ramdisk block devices, or an alternative that will give me what I want? Sure I could use disk files but I want my data stored in RAM.
F

clvic · 05-30-2008, 03:55 AM

I think that the best thing for you, is creating inside a tmpfs filesystem a file containing a disk image. And then, format this one as you want.
I sometime do like this, when I want to give a look at filesystems behaviour without formatting a disk.
You can make use of "dd" to create the disk image, e.g.
cd /tmp
dd if=/dev/zero of=sample.img bs=1048675 seek=256 count=0
creates a "sparse", 256Mb, disk image, that you can manage as you want.

fmillion · 05-31-2008, 09:49 AM

Thanks - that's an excellent solution! Never thought of doing it that way. What I did was make a file on a tmpfs filesystem then map it to a loopback device. Thanks again!