[LU-14898] sanity test_413a: (max - min) * 100 / min: division by 0 (error token is "min")

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Severity: 3
• Assignee: Lai Siyao
• Reporter: Maloo

Description

This issue was created by maloo for Andreas Dilger <[e-mail]>

This issue relates to the following test suite runs on master:
https://testing.whamcloud.com/test_sets/d6500a87-362a-4b97-a17c-cf951e79589a
https://testing.whamcloud.com/test_sets/3fd97831-6f6e-4b8e-b8de-54bf5bbe417d

test_413a failed with the following error:

Check for uneven MDTs: 
weight diff=2% must be > 100% ...Fill MDT0 with 100 files: loop 0
weight diff=2% must be > 100% ...Fill MDT0 with 100 files: loop 1
weight diff=72% must be > 100% ...Fill MDT0 with 100 files: loop 2
weight diff=72% must be > 100% ...Fill MDT0 with 100 files: loop 3
weight diff=72% must be > 100% ...Fill MDT0 with 100 files: loop 4
sanity.sh: line 24557: (max - min) * 100 / min: division by 0 (error token is "min")
test_413a returned 1

It looks like something is wrong with filling the MDT0000, since it runs multiple loops and "diff" doesn't change, until MDT0000 is totally full (min = 0). Either the statfs data is cached and not updated between loops (if the DoM writes are very fast), or the writes are not going to MDT0000 for some reason (I think this is less likely, but possible).

Another possibility is that the default MDT space balance is causing MDT usage to be much more balanced, and it is not possible to hit 100% imbalance just by writing DoM files to MDT0000? It may be that the loop also needs to create more, smaller files (e.g. 1000x64KB) so that both blocks and inodes are used.

VVVVVVV DO NOT REMOVE LINES BELOW, Added by Maloo for auto-association VVVVVVV
sanity test_413a - test_413a returned 1

Issue Links

• is related to: LU-14659 sanity test_413a: subdirs shouldn't be evenly distributed
• is related to: LU-13417 DNE3: mkdir() automatically create remote directory on MDS which has more space