Same device, two mount points? Or, overutilizing my RAM disk...

Chris Torek chris at mimsy.umd.edu
Thu Sep 13 19:04:37 AEST 1990


In article <1990Sep12.084002.5575 at hq.demos.su> dvv at hq.demos.su
(Dmitry V. Volodin) writes:
>You'd better increase the size of your cache pool. The effect is much
>better.

Well, yes and no: one of the real benefits of a RAM /tmp is that file
creation and deletion are synchronous operations, and they go a lot
faster when waiting for RAM rather than a disk. :-)  This is why
4.3BSD-reno has the virtual memory file system type.  VMFSes use RAM
when it is available, or backing store (swap space) otherwise.

Note that you must change vi to store its temporary files on a real
disk so that it can recover edit sessions after power failures, etc.
(I realize you Californians do not have daily power failures every
summer like those of us on the east coast....  Thunderstorms, is why.)

>Folks, does anyone want to discuss the pros and cons of placing the
>swap/pageing area onto the ram disk? :)

Although this was not intended seriously, there are some Unix kernels
out there where this would help.  Ten years ago some of the popular
machines (VAX-11/780...) were better at DMA I/O than cpu-mediated
memory-to-memory copies, and therefore a number of operations were
done using the paging area as a sort of memory-to-memory DMA device.

This is supposed to be fixed Real Soon Now.

>internet: <dvv at hq.demos.su>

Do svedanya,			<- will this get me into the NSA archives? :-)
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 405 2750)
Domain:	chris at cs.umd.edu	Path:	uunet!mimsy!chris



More information about the Comp.unix.admin mailing list