[GH-ISSUE #613] dbglvl=dbg causes uploads to grind to a halt after ~10 seconds #346

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opened 2026-03-04 01:44:37 +03:00 by kerem · 1 comment

kerem commented

2026-03-04 01:44:37 +03:00

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Originally created by @thomasv314 on GitHub (Jun 2, 2017).
Original GitHub issue: https://github.com/s3fs-fuse/s3fs-fuse/issues/613

Hi,

I'm not totally sure if this is as intended or not, but figured it may be worth reporting anyway.

We've been using s3fs as an S3<->SFTP bridge for quite some time now. In debugging an unrelated issue we recently ran s3fs with dbglvl=dbg. After resolving the issue, we noticed that connections would grind to a halt after about 10 seconds of uploading a file.

With dbglvl on, we saw 2.5mbs -> 10 seconds later, 30kbs.
With dbglvl unset, we saw 2.5mbs -> for the entire upload.

If this isn't a bug, hopefully this helps other people debug slow s3fs connections 😄

Additional Information

Version of s3fs being used (s3fs --version)
- Amazon Simple Storage Service File System V1.82(commit:620f6ec) with OpenSSL
- Also confirmed/experienced this w/ v1.80
Version of fuse being used (pkg-config --modversion fuse)
- 2.9.2
System information (uname -a)
- Linux ip-10-125-100-208 3.13.0-79-generic #123-Ubuntu SMP Fri Feb 19 14:27:58 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
Distro (cat /etc/issue)
- Ubuntu 14.04.4 LTS
s3fs command line used (if applicable)

/usr/local/bin/s3fs foobar-stage-sftp /home/foobar -o rw,nosuid,allow_other,nodev,use_cache=/tmp/s3_cache,iam_role=foobar-stage-s3ftp

Originally created by @thomasv314 on GitHub (Jun 2, 2017). Original GitHub issue: https://github.com/s3fs-fuse/s3fs-fuse/issues/613 Hi, I'm not totally sure if this is as intended or not, but figured it may be worth reporting anyway. We've been using s3fs as an S3<->SFTP bridge for quite some time now. In debugging an unrelated issue we recently ran s3fs with `dbglvl=dbg`. After resolving the issue, we noticed that connections would grind to a halt after about 10 seconds of uploading a file. With dbglvl on, we saw 2.5mbs -> 10 seconds later, 30kbs. With dbglvl unset, we saw 2.5mbs -> for the entire upload. If this isn't a bug, hopefully this helps other people debug slow s3fs connections 😄 #### Additional Information - Version of s3fs being used (s3fs --version) - Amazon Simple Storage Service File System V1.82(commit:620f6ec) with OpenSSL - Also confirmed/experienced this w/ v1.80 - Version of fuse being used (pkg-config --modversion fuse) - 2.9.2 - System information (uname -a) - Linux ip-10-125-100-208 3.13.0-79-generic #123-Ubuntu SMP Fri Feb 19 14:27:58 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux - Distro (cat /etc/issue) - Ubuntu 14.04.4 LTS - s3fs command line used (if applicable) ``` /usr/local/bin/s3fs foobar-stage-sftp /home/foobar -o rw,nosuid,allow_other,nodev,use_cache=/tmp/s3_cache,iam_role=foobar-stage-s3ftp ```

kerem closed this issue

2026-03-04 01:44:37 +03:00

kerem commented

2026-03-04 01:44:37 +03:00

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@ggtakec commented on GitHub (Mar 30, 2019):

What do you set the dbglevel option?

The dbglevel option can be set crit (critical), err (error), warn (warning), info (information) or dbg (debug).
I think s3fs will be slower from crit to dbg.
Especially a case of dbg, when uploading/downloading a file, a message is output for each copy operation to a temporary file, which is quite expensive.
I think that the info value is enough for normally debugging, then if you are concerned about slow speed, it is better to use info instead of dbg.
Also, the curldbg option will affect performance.

@ggtakec commented on GitHub (Mar 30, 2019): What do you set the `dbglevel` option? The `dbglevel` option can be set crit (critical), err (error), warn (warning), info (information) or dbg (debug). I think s3fs will be slower from `crit` to` dbg`. Especially a case of `dbg`, when uploading/downloading a file, a message is output for each copy operation to a temporary file, which is quite expensive. I think that the `info` value is enough for normally debugging, then if you are concerned about slow speed, it is better to use `info` instead of` dbg`. Also, the `curldbg` option will affect performance.

kerem referenced this issue

2026-03-04 01:54:08 +03:00

[PR #346] [MERGED] Fix empty directory check against AWS S3 #1473