create ramdisk filesystem

[A.Fadyushin at it-centre.ru]

> -----Original Message-----
> From: redhat-list-bounces at redhat.com [mailto:redhat-list-
> bounces at redhat.com] On Behalf Of Tom Greaser
> Sent: Thursday, September 29, 2005 9:21 PM
> To: redhat-list at redhat.com
> Subject: create ramdisk filesystem
> 
> ive been doing some looking
> and I see under my /dev that i have some
> ramdisk devices already setup..
> 
> but after mkfs + mounting one device (ram9)
> it only 16M .. how can i  create
> a ram disk of my own size requirements ?
> 
> have tried
> ramsize /dev/ram9 500000
> 
> rdev -r /dev/ram9 500000
> both .. no luck!!
> 
> at kernel boot up i can use grub to pass
> ramdisk_size=500000 and that works!!!!!
> 
> Thanks
> 

The size of ramdisk can be changed by several methods:

1. If you have the kernel source, you can set the size you need in the
kernel configuration ('Block devices' section of configuration menu).
Then you will need to recompile and reinstall the kernel.

2. You can specify the ramdisk size as a parameter at kernel boot time
(as you did).

3. If your ramdisk driver is compiled as a module (rd.o), you can unload
the module and load it again with the parameter 'rd_size' set to the
ramdisk size you need. (rmmod rd; insmod rd rd_size=<ramdisk_size>). Of
course, you will need to unmount all ramdisks before unloading the
module. Also you should note that if you are using initrd, your ramdisk
driver should be compiled as a static part of a kernel, not as a module.
Therefore, this method is incompatible with initrd.

Alexey Fadyushin.
Brainbench MVP for Linux.
http://www.brainbench.com