# Limitations of zip and unzip command on 32 bit machine



## Rax (Feb 28, 2011)

Hi,

Want to know the limitations of zip and unzip command on 32 bit machine regarding two things:
1.) Maximum no of files that can be zipped.
2.) Maximum file size.

I am creating zip of data having size approx 14GB, it makes zip file of around 6GB. And then while trying to unzip this package, just to make sure that previously created zip is fine or not, got following error message:

```
End-of-central-directory signature not found. Either this file is not a zip file, or it constitutes one disk of a multi-part 
archive
```

So want to know, is there any issue with zip and unzip command on 32-bit machine?

Thanks in advance,
Rax


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## SirDice (Mar 1, 2011)

There are only 4 bytes available for the uncompressed size in the zip header. That limits zip to 4GB, the number of entries is limited to 65535. It doesn't matter if you run it on 32 bit or 64 bit, the number of bytes in the header stays the same.

I'm not sure if the tools support ZIP64, that probably depends on the implementation.

http://en.wikipedia.org/wiki/ZIP_(file_format)


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## Rax (Mar 3, 2011)

Thanks for your clarification.

Basically, I am working with LAMP stack and using FreeBSD (i386 and amd64 server both) as a Linux component. I didn't get any issue in zipping large files >10GB on amd64 but facing problem with i386 machine.

Following are version details of FreeBSD,zip and unzip on each of machine:
1.) i386
FreeBSD 6.2-RELEASE-p7 
zip-3.0 
unzip-5.52_2

2.) amd64
FreeBSD 7.0-RELEASE
zip-3.0
unzip-5.52_3

zip-3.0 supports Zip64 on both systems. Let me know if you need any more information.

Thanks


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