Date: Tue, 14 Nov 1995 23:08:41 -0700 (MST) From: Terry Lambert <terry@lambert.org> To: babkin@hq.icb.chel.su (Serge A. Babkin) Cc: terry@lambert.org, karl@mcs.com, current@FreeBSD.ORG Subject: Re: ISP state their FreeBSD concerns Message-ID: <199511150608.XAA00327@phaeton.artisoft.com> In-Reply-To: <199511150530.KAA03475@hq.icb.chel.su> from "Serge A. Babkin" at Nov 15, 95 10:30:04 am
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> > Well, NFS lockd, for one. > > I'm sorry, I said unclear. I meant the file-based "implicit" locking methods. > I think lockd must make synchronization anyway and it must flush the caches. No, no, evil, no! > > Nope. Packet-burst. Effectively, async writes for 32 or 64k. Fixed > > window, needs an ack every burst run. > > OK, why it is good for Netware and bad for NFS ? Because the async is on the client; if it fails, it can retry. The average system call overhead in SVR4 is 20uS. The average packet turnaround on a NetWare server is on the order of 60uS. Obvious UNIX will have a hell of a time turning a packet around as fast as a NetWare server. The loss for NFS is that the async writes are not performed by the client. If the client did a "window" worth of async writes an did an fsync() before letting go, then it would work. Basically, it fails because the client is stupid and NFS is not a connection oriented protocol. > > > BSDI NFS - about 300K/s > > > FreeBSD NFS - about 12K/s > > > > One wonders what BSDI does... maybe implements pcnfsd in kernel code? > > Nope, I have experimented with pcnfsd from BSDI compiled in FreeBSD. I know > no details of PCNFS protocol, but if every request neeeds additional request > to pcnfsd it's IMHO strange. BTW, I have experimented without pcnfsd at all, > with -n key of mountd and results were the same. How else are you going to support findfirst/findnext and short name semantics?!? PCNFS protocol is a bad thing. The ability to use it on tof of NFS with no penalty comes from the fact that typically you *don't* double up on requests, and sinces it's connectionless, it really doesn't matter which server software you go to to make the request. > May be BSDI uses asyncronous mode by default. I don't know. It's a big lose on reliability under adverse conditions if they do. I find it hard to believe they'ed do this, though SGI does and (I think) SVR4 now does (it didn't, formerly). > > Consider a print job that you cause the file to be deleted after it's put > > in the queue -- a lot of email systems, like CC:Mail, do this. > > Explain me please where is the problem ? I see none. You run printing, > it gets vnode of file, opens it and starts copying into its spool. After > this you gat the same vnode and issue an "unlink" request. The vnode gets > unlinked but it is still in-core with nonzero number of "opens" and thus > it will not be removed until the print system closes it. I see no place here > where immediate reporting or windowed writes can crash anything. Depends on how you implement the spooling services. It was just an example of the kind of thing you can screw up. The DOS has no concept of a link. And if it did, you couldn't allow the unlink until after it had been committed. > > Well, these figures were current as of last year... > > > > You can license NUC (NetWare UNIX Client) source code for $100,000. > > You can license NWU (NetWare 4.x for UNIX Server) source code for $150,000. > > > > Or you can license both + UnixWare source code for $250,000 (hmmmm... I > > wonder what value UNIX source code has... $250,000 - $150,000 - $100,000. > > 8-) 8-)). > > From the point of view of end-user the cost of binary licence is much > different from these numbers. The licence per 1 user for NW 3.12 costs > about $50. For example SCO is not cheaper. Depends on how many copies you think you can sell. > > With IPX stack latency corrected (mostly an artifact of the Streams > > implementation on UnixWare), NWU will outperform Native NetWare on > > identical hardware. By as much as 30%. > > BTW will UnixWare+NWU binary license be comparable with native NetWare > by cost ? I dunno. Probably not. Novell is unloading UNIX on SCO, and they really don't want a competitor to their main cash cow. > > Change the PCNFS server, and if possible, the PCNFS client. > > I know that different PCNFS clients make difference in performance but I > never throught that pcnfsd may change the performance. Its manual page > says that it is used for logging in and out only. Look at the source. The manual page lies. Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers.
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