Re: [TCLUG:9949] How do I set up a ramdisk?

[Karl Morgan <ksm@dogbrain.com>]

On Wed, 10 Nov 1999, Carl Wilhelm Soderstrom wrote:


> so do the ramdisks all always exist at boot time, but just have a
> size of 0?

Yes, thats my understanding. You can see this during bootup

    # dmesg | grep -i ram
    RAM disk driver initialized:  16 RAM disks of 4096K size

> then when you write data to them, they fill up to a maximum size of
> 4MB?

Yes again...

> >Just a note, it seems the maximum size of a ramdisk is 4Mb unless
> >you are willing to modify /usr/src/linux/drivers/block/rd.c and
> >recompile your kernel.

> hmm. that seems a bit silly. but maybe I'm biased.  here at work we
> use ramdisks on a lot of computers (useful for .zip'ing & unzip'ing
> files, done by scripts); and 4MB is the smallest size we use. there
> are a couple of 10-12MB ramdisks that people use.  i would have
> guessed that there would be more call for bigger ramdisks; but I
> suppose HDDs are so fast these days; it's not as important as it
> once was.

I was underinformed, you can modify rd.c and set a larger default
ramdisk size, but the following boot arg can be used to change the
default size also.

    ramdisk_size=8192   (or whatever size it is your going after...)

Regards

					- Karl