root@MCIRPS2.MED.NYU.EDU (08/07/90)
It seems that there are two uses for tmp: a standard place to put temp files and buffers and a place to put trash. I was wondering of it would be of value to speed up compiles and shell scripts if the tmp file systems were put on a small (20-40 megabyte) separate fast hard disk, perhaps a ram disk. Are there any ram disks available for sgi machines, and does anyone have experience with them ? Are they worth it ? Dan. +-----------------------------------------------------------------------------+ | karron@nyu.edu Dan Karron | | . . . . . . . . . . . . . . New York University Medical Center | | 560 First Avenue \ \ Pager <1> (212) 397 9330 | | New York, New York 10016 \**\ <2> 10896 <3> <your-number-here> | | (212) 340 5210 \**\__________________________________________ | +-----------------------------------------------------------------------------+
fsfacca@ZoSo.lerc.nasa.gov (Tony Facca) (08/07/90)
>Are there any ram disks available for sgi machines, and does anyone have >experience with them ? Are they worth it ? I think you can probably call the same people who sell those third party inodes. :-) -- ----------------------------------------------------------------------------- Tony Facca | fsfacca@avelon.lerc.nasa.gov | phone: 216-433-8318 ----------------------------------------------------------------------------- You are at Witt's end. Passages lead off in *all* directions.
olson@anchor.esd.sgi.com (Dave Olson) (08/08/90)
In <1990Aug7.124134.7563@eagle.lerc.nasa.gov> fsfacca@ZoSo.lerc.nasa.gov (Tony Facca) writes: | >Are there any ram disks available for sgi machines, and does anyone have | >experience with them ? Are they worth it ? | | I think you can probably call the same people who sell those third party | inodes. :-) Actually, there ARE companies that make SCSI based RAM disks. We measured sustained throughput of about 4Mb a second on one of them (provided you have a machine with the IO3 board, or a 4D25). That isn't blindingly fast, but it is about twice as fast as the fastest available SCSI disk drives, and only slightly slower than IPI. One of the companies making such drives is Ramstor, someplace in Colorado. They aren't cheap, and of course we are not endorsing them, saying they will work for you, etc., etc. CPU memory based RAM disks really aren't all that great, since unless you have a Power series with 128 Mb of RAM, you probably won't have enough RAM to help a whole lot. Irix 3.3 does allow you to use 'all' of 'unused' memory as part of the buffer/page cache automatically, which can speed some file accesses quite a bit. -- Dave Olson Life would be so much easier if we could just look at the source code.
karron@MCIRPS2.MED.NYU.EDU (08/08/90)
How would you configure a system to use a lot (>32 mb) core as file buffer space ? How can you measure the performance improvement/degradation ? dan. +-----------------------------------------------------------------------------+ | karron@nyu.edu Dan Karron | | . . . . . . . . . . . . . . New York University Medical Center | | 560 First Avenue \ \ Pager <1> (212) 397 9330 | | New York, New York 10016 \**\ <2> 10896 <3> <your-number-here> | | (212) 340 5210 \**\__________________________________________ | +-----------------------------------------------------------------------------+
yohn@tumult.asd.sgi.com (Mike Thompson) (08/10/90)
In article <9008081842.AA24270@mcirps2.med.nyu.edu>, karron@MCIRPS2.MED.NYU.EDU writes: > How would you configure a system to use a lot (>32 mb) core as file buffer > space ? > > How can you measure the performance improvement/degradation ? Upgrade to Release 3.0 when it becomes available. It has a flexible file buffer cache that uses whatever free memory is available, without having to do any system configuration. The cache shrinks as user processes demand memory. You can reconfigure a 3.2 buffer cache by upping NBUF in /usr/sysgen/master.d/kernel and regenerating the kernel (via lboot). It is not wise to make NBUF any bigger than 400, which will give you an effective buffer cache of between 1.5 Mb and 6.4 Mb, depending on your instantaneous use. (The buffers manage varying amounts of memory, depending on the underlying operations.) Mike Thompson
archer@elysium.esd.sgi.com (Archer Sully) (08/10/90)
In <66584@sgi.sgi.com> yohn@tumult.asd.sgi.com (Mike Thompson) writes: *In article <9008081842.AA24270@mcirps2.med.nyu.edu>, karron@MCIRPS2.MED.NYU.EDU writes: *> How would you configure a system to use a lot (>32 mb) core as file buffer *> space ? *> *> How can you measure the performance improvement/degradation ? * *Upgrade to Release 3.0 when it becomes available. Mike means 3.3. -- Archer Sully | "Hippie, you think everything's a conspiracy." archer@esd.sgi.com | "Everything is."
andrew@alice.UUCP (Andrew Hume) (08/15/90)
anamrtic(sp?) sells ram disks witha scsi interface. they sustain 3MB/s synchronous. they come in various sizes; the biggest is 240MB. they have a 8in disjk form factor and cost about $115/MB.