On Tuesday 23 September 2003 23:45, Guillaume Morin wrote:
> The problem is still the number of available minor numbers. If I am not
> mistaken, the kernel gives 4 minor numbers for one dasd. This means you
> can mount at the same time 255/4 = 63 disks. You can still play with the
> kernel ignore list, I guess. Am I missing anything ?
When you are using the hotplug package that comes with sles8 or you have
devfs, you can use far more disks because the dasd driver allocates extra
major numbers when needed. The actual limitation is when you try to do
I/O on all the disks at the same time, because the block layer in linux
works better with a small number of disks and you may have to install
insane amounts of physical memory to saturate 100 disks.
If you need many disks only for the size, defining them as model-27
helps.
> Anyway, the 2.6.0 kernel is supposed to be released with 32 bits device
> numbers.... So this should not be a problem anymore.
Yes, although it will not be easy to switch between 2.4 and 2.6 if you
have created the device nodes yourself (2.4 sees /dev/dasdbk1 at 254:1,
2.6 will have it at 94:257).
Arnd <><
