Difference between storage_usage and df -Th output
We were trying to use storage_usage view to monitor disk space usage in Vertica nodes. However, we failed to tally the numbers from storage_usage view with the output of df -Th command. So, we became unsure if we are missing anything.
The query I used-
select path,device, filesystem, round(used_bytes/power(1024,3),2) as used_GB, usage_percent from storage_usage where node_name='v_db_node0001' order by 2,3
Output of above query-
| path | device | filesystem | used_GB | usage_percent |
| | | vertica | 221.28 | 5.92 |
| /boot | /dev/sda1 | ext4 | 0.08 | 32.96 |
| / | /dev/sda3 | ext4 | 65.47 | 8.41 |
| /vertica/data | /dev/sdb | ext4 | 155.81 | 5.27 |
| /vertica/catalog | /dev/sdc | ext4 | 50.91 | 7.26|
| /dev | udev |devtmpfs | 0.0 | 0.0 |
While, output from df -Th looks like below:
Filesystem Type Size Used Avail Use% Mounted on
/dev/sda3 ext4 779G 26G 714G 4% /
tmpfs tmpfs 64G 0 64G 0% /dev/shm
/dev/sda1 ext4 243M 68M 163M 30% /boot
/dev/sdb ext4 2.9T 5.7G 2.8T 1% /vertica/data
/dev/sdc ext4 702G 16G 651G 3% /vertica/catalog
Is there any explanation for this variation?
Thanks,
Rupendra
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