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From: lm@snafu.Sun.COM (Larry McVoy)
Newsgroups: comp.arch
Subject: Re: Real disk FASTER than Ram disk
Message-ID: <136299@sun.Eng.Sun.COM>
Date: 27 May 90 19:06:57 GMT
References: <1990May22.174627.11610@hcr.uucp> <637@sibyl.eleceng.ua.OZ> <5461@titcce.cc.titech.ac.jp> <641@sibyl.eleceng.ua.OZ>
Sender: news@sun.Eng.Sun.COM
Reply-To: lm@sun.UUCP (Larry McVoy)
Organization: Sun Microsystems, Mountain View
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In article <641@sibyl.eleceng.ua.OZ> ian@sibyl.OZ (Ian Dall) writes:
>>Ram disk is actually effective when many sync writes are issued, such as
>>compilation of many small files.
>
>Can you elaborate? What are these sync writes? If they consist of an
>fsync or whatever after every write (or after each process completes),
>then why are the fsyncs being done in the firstplace. If the compiler
>is broken, fix it. I still see no reason to add a RAM disk. 

Directory updates are synchronous.  Why they are is a topic for an OS
course, not comp.arch - I'd be happy to explain offline.

As a side note: check out Sun's tmpfs.  It's a variable sized ram disk that
doesn't do the extra copy.  I think it solves most of the problems that
were discussed in this thread.
---
Larry McVoy, Sun Microsystems     (415) 336-7627       ...!sun!lm or lm@sun.com