Xref: utzoo unix-pc.general:1783 comp.sys.att:4862 Path: utzoo!utgpu!watmath!clyde!att!osu-cis!n8emr!uncle!jbm From: jbm@uncle.UUCP (John B. Milton) Newsgroups: unix-pc.general,comp.sys.att Subject: Re: Large files on the Unix PC Keywords: unixpc, unix, files Message-ID: <432@uncle.UUCP> Date: 3 Dec 88 07:22:41 GMT References: <5466@rphroy.UUCP> Reply-To: jbm@uncle.UUCP (John B. Milton) Organization: U.N.C.L.E. Lines: 32 In article <5466@rphroy.UUCP> tkacik@rphroy.UUCP (Tom Tkacik) writes: >The documentation for the UnixPC says that there is a 1 Meg limit on the >size of files. I have used files that are larger than this. >The largest was about 1.4Meg. Does anyone know what the real limit is? >Am I playing with fate by having files of this size? >I thought that Unix files were able to be much larger than this. >What is it about the UnixPC that makes a limit like this? The real limit on file sizes has to do with the longest list of blocks your files system can create. Things that affect this: The size of your blocks (512) How many bytes are used to number the blocks (3) blocks listed in the i-node (13) blocks listed in the first indirect (170) blocks listed in the second indirect (170*170=28900) blocks listed in the third indirect (170*170*170=4913000) For a total of 4942083 blocks of 512 bytes=2530346496 bytes The number of bytes in the file is also saved in the i-node as a 32 bit number. The default limit (ulimit(2)) for users on the UNIXpc is 2147483647. I HAVE created 2 gig files on the UNIXpc, so I know it works. Because of the indirect blocks, the du(1) of a file is larger than the size of the file when the size exceeds 13 blocks and allocates an indirect block John -- John Bly Milton IV, jbm@uncle.UUCP, n8emr!uncle!jbm@osu-cis.cis.ohio-state.edu (614) h:294-4823, w:764-2933; Got any good 74LS503 circuits?