Re: Bug in cp ???

[Shamsher Sandhu]

We are copying from ext2 to nfs (ext2) file system. The version of cp
that we have here is 4.0p. I was not using --sparse=always. I will try
it and see the results.

The way oracle allocates data files is such that they are bound to have
a lot of blocks of 0 bytes. We have oracle block size of 8 kb and fs
block size is 512 bytes. In empty blocks, oracle only writes the header
and rest of the block is empty. I hope using the sparse option will
solve this problem. But with growing use of oracle in Linux arena, it
should be the default functionality, imho.

Shamsher Sandhu

Jim Meyering wrote:
> 
> Shamsher Sandhu <address@hidden> wrote:
> | I am using Oracle here on Redhat 6.2 load. We are copying oracle
> | databfiles for backup using cp command. The copy is happening when oracle
> | is down. The copy is being done across nfs. The problem is that sometimes
> | the copied file is of different size than the original one. The difference
> | can range between 200 to 300 mb on a 500 mb file. I discovered this while
> | to restore from backup and I realised that I could not recover beacuse of
> | thius problem. I have seen this problemn at least 5 times after that and
> | happens with many files. Could it be that oracle datafiles have embedded
> | EOF characters that confuse cp into thinking that the file has ended or
> | what. Any way I will leave it upto you to figure it out. But please keep
> | me informed about this problem.
> 
> Thanks for the report.
> >From what type of file system (df -T) are you copying?
> What type of file system are you copying *to*?
> What version of cp are you using?
> 
> Did you try using the --sparse=always option?
> 
> There may be something wrong with cp's code that detects
> whether a file is sparse.
> 
> Did you try comparing the files before and after?
> The destination file (the one that's way too big)
> probably has big blocks of zero bytes that correspond to
> `holes' in the original.
> 
> Would you please see if the problem persists when using the
> latest test release?
> 
>   ftp://alpha.gnu.org/gnu/fetish/fileutils-4.0.32.tar.gz
> 
> I expect to make an official release of the fileutils within the next
> month or so, and would really like to resolve any problems before then.
> 
> Regards,
> Jim

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