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Zero size files can't be read from fuse mount

Hello,

I wanted to report on JIRA the issue we met today on Citrine, but it seems I don’t have the correct access any more, gives an error, so I post it here.

The following behaviour breaks the functioning of some programs (the file is non-existent at the beginning), and is clearly incorrect. It can easily be reproduced this way :

/eos/path/to/file $ touch test-file
/eos/path/to/file $ cat test-file
cat: test-file: Numerical result out of range
/eos/path/to/file $ truncate -s0 test-file
/eos/path/to/file $ cat test-file
/eos/path/to/file $
/eos/path/to/file $ cp test-file test-file-new
/eos/path/to/file $ cat test-file-new
cat: test-file-new: Numerical result out of range

So even copying a readable empty file creates an unreadable one.

The reason might be because the replicas are not present on the FSTs :

Correct file :

$ eos file check /eos/path/to/file/test-file
path="/eos/path/to/file/test-file" fid="0001a762" size="0" nrep="2" checksumtype="adler" checksum="0000000100000000000000000000000000000000"
nrep="00" fsid="5" host="s-jrciprcids93v.cidsn.jrc.it:1095" fstpath="/data02/0000000a/0001a762" size="0" statsize="0" checksum="0000000100000000000000000000000000000000"
nrep="01" fsid="2" host="s-jrciprcids92v.cidsn.jrc.it:1095" fstpath="/data02/0000000a/0001a762" size="0" statsize="0" checksum="0000000100000000000000000000000000000000"

Incorrect file :

eos file check /eos/path/to/file/test-file-new
path="/eos/path/to/file/test-file-new" fid="0001a763" size="0" nrep="2" checksumtype="adler" checksum="0000000100000000000000000000000000000000"
nrep="00" fsid="6" host="s-jrciprcids93v.cidsn.jrc.it:1095" fstpath="/data03/0000000a/0001a763" size="0" statsize="18446744073709551615" checksum="0000000100000000000000000000000000000000"
nrep="01" fsid="3" host="s-jrciprcids92v.cidsn.jrc.it:1095" fstpath="/data03/0000000a/0001a763" size="0" statsize="18446744073709551615" checksum="0000000100000000000000000000000000000000"

Observed with MGM 4.2.12 and FST 4.2.18, and reproduced with an instance freshly fully upgraded to 4.2.19

Hi Frank,

as it was mentioned in EOS Communication Workflows, now you can just send an email to eos-support@cern.ch reporting the issue and requesting the issue to be registered in JIRA with the corresponding description. Then, the EOS team will create it accordingly and follow up.

I hope it helps,
Maria

Dear Maria,

You are right, thank you for reminding this, it sure helps! I will do as foreseen. Feel free to remove this post, if needed.

Franck

Hi Frank,

Did you resolve the problem? We also observed it with EOS server 4.2.16. If you have fixed it, please help us.

Thank,
yaodong@IHEP

Hi Yaodong,

That was registered as a bug, and fixed later on. We got it fixed in JRC by upgrading our MGMs and FSTs to the 4.2.20 version.

Greetings,
Veselin

Hi Veselin,

Yes, I tested it in Version 4.2.22, and the bug was fixed.

Thanks,
Yaodong