stone@sheba.UUCP (stone) (08/14/86)
What limits exist on the size of single transfers to/from disk and tape (tape block size) in the Unix world, and elsewhere. What effects on performance are there for using larger size transfers (i.e. do other requests pay a penalty while a large transfer is being serviced)? What are appropriate limits (if any)? For example our system (Arete A1000 SYS V.2.2) currently supports up to 16k for tape blocks and up to 256k for disk transfers. David Stone Arete Systems !sun!arete!stone or !ihnp4!hplabs!hpspdla!sheba!stone
judah@whuxcc.UUCP (Judah Greenblatt) (08/16/86)
> What limits exist on the size of single transfers > to/from disk and tape (tape block size) in the Unix > world, and elsewhere. The maximum tape block size for Unix machines I have used: AT&T 3B20 6K max, 5632 byte recommended Pyramid 98x 30K max CCI Power 6/32 32K max, 16K recommended > What effects on performance are there for using larger > size transfers (i.e. do other requests pay a penalty > while a large transfer is being serviced)? On the CCI, transfers of over 16K bytes at 6250 BPI disable interrupts overly long, causing the system to loose clock interrupts. -- Judah Greenblatt "Backward into the Future!" Bell Communications Research uucp: {bellcore,infopro,ihnp4}!whuxcc!judah Morristown, New Jersey, USA arpa: whuxcc!judah@mouton.com * Opinions expressed are my own, and not those of the management.