I'm creating ram block devices on a linux machine for a project we're working on.
I don't want to use tmpfs.
When I use module brd to create a ramdisk I run the command
modprobe brd rd_size=1048576
This creates 16 devices -> /dev/ram[0-15] (all of size 1 GB)
But now I want to create two ramdisks of different sizes, say 1Gb and 2Gb.
I also understand I might be able to use lvm to "merge" two devices together and create a new 2GB device from two 1GB devices.
But I want the module to create ramdisks of different sizes without having to do the merging.
I've looked around for a method to do this, but it just seems that there is no way.
Does anyone know if there is a way to do this?
Best Answer
I'd been looking for similar information on RAM disks (in my case, planned RAM disk as part of RAID 1 array). For a partial answer, as I'm not sure how to create RAM disks of differing sizes:
Try: modprobe brd rd_nr=1 rd_size=1048576 max_part=0
Which should create one, 1GB RAM disk. Perhaps tailor rd_nr=1 to rd_nr=3? That should give three 1G RAM disks, leaving assembling them to 2GB perhaps to LVM?
Referenced solution, and pardon the necro-post answer (there remains very lacking documentation on this subject): http://forums.debian.net/viewtopic.php?f=5&t=114458