Mount Point Size

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1

Hello,

I was trying to get details of mout points but found that df and ansible setup module not returns same size or block count.

This is case even I specify bloc size for df command

checkout below :

ravikumar:~ # df -Th --block-size=4096

Filesystem Type 4K-blocks Used Available Use% Mounted on
devtmpfs devtmpfs 2002838 0 2002838 0% /dev
tmpfs tmpfs 2005039 39 2005000 1% /dev/shm
tmpfs tmpfs 2005039 31067 1973972 2% /run
tmpfs tmpfs 2005039 0 2005039 0% /sys/fs/cgroup
/dev/sda3 ext3 23445742 3929894 18323208 18% /
/dev/sda1 ext3 250579 12706 224728 6% /boot
tmpfs tmpfs 401008 0 401008 0% /run/user/40405
tmpfs tmpfs 401008 4 401004 1% /run/user/483
tmpfs tmpfs 401008 0 401008 0% /run/user/0

Ansible result :

“block_available”: 18323119,

“block_size”: 4096,
“block_total”: 23445742,

Can some one comment on this why they are different.

Thanks !!

2

The block_total is equal and block_available just have a difference of 89 blocks.

I doubt that the ansible fact command checking the disk have been run at the same millisecond/nanosecond as the df command.
In a live file system a lot of IO is ongoing, like temp files been created av deleted, so it normal that available space change all the time.

Ansible is just running Python os.statvfs so with this command you might be lucky to see that they are the same.

df -Th --block-size=4096 /; python -c "import os;print os.statvfs('/')"

But this oneliner with two commands is run one after the other, so it too might be different.

3

Thanks !!!

Got you point.