joes@islsun3.mse.lehigh.edu (Joe Sieczkowski) (08/24/89)
I recently moved my PC-NFS server from a fairly loaded 8Meg 3/260 to an unloaded 32Meg 4/280 (new). I expected a large performance increase; however over-all performance on a mounted drive only increased by a couple percent. This test was done on a PS2/50 with a 3c523 board. Is there anything I can do to increase the performance? The 4/280 is intended to be a dedicated server for several applications. I would appreciate any help. Joe
geoff@hinode.East.Sun.COM (Geoff Arnold @ Sun BOS - R.H. coast near the top) (08/24/89)
In article <JOES.89Aug23230444@islsun3.mse.lehigh.edu> joes@islsun3.mse.lehigh.edu (Joe Sieczkowski) writes:
::
::I recently moved my PC-NFS server from a fairly loaded 8Meg 3/260 to
::an unloaded 32Meg 4/280 (new). I expected a large performance
::increase; however over-all performance on a mounted drive only
::increased by a couple percent. This test was done on a PS2/50 with
::a 3c523 board.
::
::Is there anything I can do to increase the performance? The 4/280
::is intended to be a dedicated server for several applications.
::
::I would appreciate any help.
::
::Joe
I assume you're running 3.0.1 with the improved cache code. You are?
Then the gating factor is the write access to the disk on the
server. The best help here is the new Legato accelerator board.
See comp.newprod or Unix Review for info. (Bob: d'you want to
post anything here about it?)
Geoff Arnold, Internet: geoff@East.Sun.COM
PCDS Group, Sun Microsystems Inc.
---------------------------------------------------------------------------
Recording of the week: ALMOST ACOUSTIC by the Jerry Garcia Acoustic Band.blyon@legato (Bob Lyon) (09/08/89)
In article 756@east.East.Sun.COM, Geoff Arnold says: ] In article <JOES.89Aug23230444@islsun3.mse.lehigh.edu> joes@islsun3.mse.lehigh.edu (Joe Sieczkowski) writes: ] :: ] ::I recently moved my PC-NFS server from a fairly loaded 8Meg 3/260 to ] ::an unloaded 32Meg 4/280 (new). I expected a large performance ] ::increase; however over-all performance on a mounted drive only ] ::increased by a couple percent. This test was done on a PS2/50 with ] ::a 3c523 board. ] :: ] ::Is there anything I can do to increase the performance? The 4/280 ] ::is intended to be a dedicated server for several applications. ] :: ] ::I would appreciate any help. ] :: ] ::Joe ] ] I assume you're running 3.0.1 with the improved cache code. You are? ] Then the gating factor is the write access to the disk on the ] server. The best help here is the new Legato accelerator board. ] See comp.newprod or Unix Review for info. (Bob: d'you want to ] post anything here about it?) ] Yes. But first let me apologize for a late response. I hope that this is not too promotional... The Legato accelerator board, Prestoserve (tm, patent pending) is a hardware and software product that installs into any Sun VMEbus system that runs SunOS 4.0 or later. The VME hardware is mostly battery-backed, non-volatile, low power SRAM. How it works: The Prestoserve software is a UNIX driver that interposes itself between SunOS and the real device drivers. It intercepts synchronous write requests and caches them in the non-volatile memory. The Prestoserve driver uses a modified LRU algorithm to eventually, asynchronously flush its non-volatile cache to the actual disks. Because the major functionality is delivered via a driver, it installs easily into object only distributions. The driver's interposition guarantees that Prestoserve works properly with any (and every) disk and controller installed today. Why it works: The NFS protocol is stateless; NFS servers are *not* stateless, but to behave properly in the eventuality of crashes, NFS servers must commit state changes to non-volatile storage (normally a disk) before acknowledging state-change requests like write, create, remove, etc. One write request will turn into two synchronous devices writes - one to put the client's data on the disk, the other to update the file's inode information. If the file is large, then a third synchronous device write is required to update the file's indirect block. By copying what the UNIX kernel believes to be synchronous writes into NV RAM, Prestoserve gives back the UNIX file system performance that NFS took away. This is accomplished by: - write elimination: In any given interval only a small number of files are being modified. Writes of the inodes or indirect blocks inevitably "hit" a cached entry in the NV RAM. In practice, this eliminates 50% - 70% of all physical disk writes on the NFS server. (Although NFS modification operations are less than 15% of the NFS operation mix, they cause close to 70% of all IO on the server.) - IO staging: Writes that eventually goes to the actual disks are written asynchronously, allowing the disk drivers to schedule those writes in a manner that takes advantage of disk arm locations, rotational delays, and other pending IO requests. - Lower perceived latency: Since writes occur at memory speeds, NFS clients see write speeds equal to NFS read speeds. Is it real? Legato currently runs 10 diskless 3/50's, 4 diskless 3/80's, and two floppy PC-NFS (Release 3.0) machines off of one "presto-ized" 3/160 (Release 4.0.3) server with a Xylogics 451 controlling two 850 megabyte SMD Sabres and a Ciprico 3500 SCSI host adapter controlling two 580 megabyte SCSI Wren V's. Performance is great! We believe that the *CPU* will saturate at around 20 clients. A PC-NFS-based beta site (I cannot disclose their name) measured a 600% (!) performance increase after installing Prestoserve into their Sun 4/110 server. 600% is a bit unbelievable. However, we expect dramatic improvements to PC-NFS networks because PC applications typically write small, uncached blocks (e.g. 512 bytes). This means that for the PC-NFS client to write 8 Kbytes, the disk must perform 32 writes (or 48 writes to a large files) without Prestoserve. With Prestoserve the same task requires only 2 (or 3) asynchronous writes to occur. In conclusion, I am not surprised that Joe Sieczkowski is dismayed that his upgraded server only delivers 2% more performance. His upgrade addressed the instruction execution latency (which is not a big problem on Sun3-class servers); it did nothing to address the IO latency (measured in many milliseconds) which usually is the NFS server bottleneck. More information can be obtained from: Legato Systems, Inc. 260 Sheridan Ave. Palo Alto, CA 94306 415-325-2200 or email to prestoserve-request@Legato.COM, or sun!legato!prestoserve-request. Bob Lyon
geoff@hinode.East.Sun.COM (Geoff Arnold @ Sun BOS - R.H. coast near the top) (09/08/89)
In article <952@legato.LEGATO.COM> blyon@Legato.COM (Bob Lyon) writes: >[Lots of neat stuff about Prestoserve.] >A PC-NFS-based beta site (I cannot disclose their name) measured a >600% (!) performance increase after installing Prestoserve into their >Sun 4/110 server. 600% is a bit unbelievable. However, we expect >dramatic improvements to PC-NFS networks because PC applications >typically write small, uncached blocks (e.g. 512 bytes). >This means that for the PC-NFS client to write 8 Kbytes, the disk must >perform 32 writes (or 48 writes to a large files) without Prestoserve. >With Prestoserve the same task requires only 2 (or 3) asynchronous >writes to occur. Just a small clarification. PC-NFS will write min(tsize,8192) byte blocks if requested by the application. Most apps still think in diskette terms, however, and so relatively few take advantage of this. We do cache writes, but the buffer cache is relatively tiny (because everyone's beating on us about size). So, if you measure things by COPY C:BIGFILE G: you won't see much of a win; with dBase or Lotus in the other hand..... Geoff Arnold, Internet: geoff@East.Sun.COM PCDS Group, Sun Microsystems Inc. --------------------------------------------------------------------------- Most bizarre title of the week: "LAN Standards - Do you Need Them?" (in BYTE)
beame@maccs.dcss.mcmaster.ca (Carl Beame) (09/09/89)
> >A PC-NFS-based beta site (I cannot disclose their name) measured a >600% (!) performance increase after installing Prestoserve into their >Sun 4/110 server. 600% is a bit unbelievable. However, we expect >dramatic improvements to PC-NFS networks because PC applications >typically write small, uncached blocks (e.g. 512 bytes). >This means that for the PC-NFS client to write 8 Kbytes, the disk must >perform 32 writes (or 48 writes to a large files) without Prestoserve. >With Prestoserve the same task requires only 2 (or 3) asynchronous >writes to occur. > >More information can be obtained from: > >Legato Systems, Inc. >260 Sheridan Ave. >Palo Alto, CA 94306 >415-325-2200 > I can believe it. We did some benchmarks of our PC based NFS (BWNFS) on a Model 80 with a WD8003E card . We ran test5 from the conectathon ( 1Mbyte read and write tests). The DOS transfer rates were 101 KBytes/sec write and 916 Kbytes/sec read. I would presume that the Prestorserve board would make writes almost as fast as reads, and we would get an 800% improvement! We use 8192 bytes for both read and write. - Carl Beame Beame@McMaster.CA
boyter@bimbo.UUCP (Maj Brian Boyter) (09/09/89)
In article <952@legato.LEGATO.COM>, blyon@legato (Bob Lyon) writes: > > A PC-NFS-based beta site measured a > 600% performance increase after installing Prestoserve into their > Sun 4/110 server. 600% is a bit unbelievable. However, we expect > dramatic improvements to PC-NFS networks Bob.... In your article you say you expect "dramatic improvements to PC-NFS networks"... Why doesn't Prestoserve speed-up NFS networks in general (i.e. what about NFS networks where the clients are other Sun workstations, not PCs)???? Brian -- --------------------------------------------------------------- Maj. Brian A Boyter US Army Foreign Science & Technology Center Charlottesville, Va 22901 __ off: (804)980-7362 ( ) home: 973-9440 { } boyter%bimbo.uucp@virginia.acc.virginia.edu ( ) || Nuke'm 'till they glow || ...Then shoot'm in the dark ________< >_______
mojo@legato (Joseph Moran) (09/15/89)
In article <436@bimbo.UUCP> boyter@bimbo.UUCP (Maj Brian Boyter) writes: >Bob.... > >In your article you say you expect "dramatic improvements to PC-NFS networks"... >Why doesn't Prestoserve speed-up NFS networks in general (i.e. what about >NFS networks where the clients are other Sun workstations, not PCs)???? Bob is away from his desk for this week, so I'll respond to your question. Prestoserve most definitely does "speed-up NFS networks in general". Bob's point was that it can be even *more* dramatic when used with PC-NFS clients using small transfer sizes. For example, a beta site measured a 600% performance increase after installing on Prestoserve on a Sun serving PC-NFS clients. Our simulations show a 50% to 300% improvement using Prestoserve with an NFS operations mix that was taken from a software development mix for a server with about a 50/50 mix of diskless and diskful clients running SunOS 4.0 (34% lookup, 22% read, 15% write, 13% getattr, 2% create). Your mileage will vary based on operations mix and server configuration and load level. Prestoserve shows the most dramatic improvements on heavily loaded servers with file systems that are accessed for both reading and writing. Joseph Moran Legato Systems Inc. 260 Sheridan Avenue Palo Alto, CA 94306 (415) 329-7886 mojo@legato.com or {sun,uunet}!legato!mojo