4MByte limit in IMFS for each file?

till strauman at slac.stanford.edu
Sun Feb 23 16:39:48 UTC 2003


Thomas.

I hit the same limit when copying large files from TFTPFS to IMFS for
loading them with CEXP.

You have to increase the IMFS blocksize (the default being 128b -
AFAIK, the max number of blocks is limited, hence increasing the
blocksize will help) in the file

cpukit/libfs/src/imfs/imfs.h

look for IMFS_MEMFILE_BYTES_PER_BLOCK

HTH

-- Till

Thomas Doerfler wrote:

>Hello,
>
>it's me again :-)
>
>When I tried out my "fileio" sample, I hit a strange 4MByte 
>limit when creating files in the IMFS. I was working on a 
>PC386 target with 16MByte of memory (and most of it was always 
>available on the heap). 
>
>
>When I tried to create big files (like 8MB), the write call 
>always failed (with a "no space left on device" error), 
>directly after reaching a 4MByte file size boundary. 
>
>This limit does not exist on the DOSFS, only when writing to 
>the IMFS. I tried it out on a MBX8xx system (with 16MByte of 
>RAM) and there I hit the limit also after 4MBytes.
>
>I was browsing through the IMFS sources and did not find any 
>reason for this limitation, and I did not yet run the test 
>with a debugger.
>
>Any hints on that issue?
>
>wkr,
>	Thomas.
>--------------------------------------------
>IMD Ingenieurbuero fuer Microcomputertechnik
>Thomas Doerfler           Herbststrasse 8
>D-82178 Puchheim          Germany
>email:    Thomas.Doerfler at imd-systems.de
>PGP public key available at: http://www.imd-
>systems.de/pgp_keys.htm
>






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