[LU-9708] "ls -s" result changed over time

• Status: Resolved
• Project: Lustre
• Affects Version/s: Lustre 2.10.0
• Type: Bug
• Priority: Minor
• Reporter: Jian Yu
• Assignee: WC Triage
• Resolution: Not a Bug

Environment

Lustre Build: https://build.hpdd.intel.com/job/lustre-master/3607/
Distro: RHEL 7.3

• Severity: 3

Description

"ls -s" result changed over time:

# pwd
/mnt/lustre
# ls -s
total 0
# touch f
# ls -s f
0 f
# echo a > f
# ls -s f
1 f
# ls -s f
4 f

After about 30 seconds, the allocated size of file f was changed from 1 block to 4 blocks.

Comments

[Andreas Dilger]

This is not a bug. While the file is in the client cache, we don't know how much space it will actually use on disk so it is just an estimate based on the file size. Once the data is flushed from the client to disk the blocks count reflects the actual space usage on disk.

Is there some problem that this causes, or just something you noticed?

[Jian Yu]

Hi Andreas,
I found this issue while investigating LU-9663.