4MByte limit in IMFS for each file?

Angelo Fraietta angelo_f at bigpond.com
Sun Feb 23 23:03:24 UTC 2003


So what is the largest file size?

till wrote:

> 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
>>
>
>
>
>

-- 
Angelo Fraietta

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