uname -aLinux CentOS01.localdomain 3.10.0-229.14.1.el7.x86_64 #1 SMP Tue Sep 15 15:05:51 UTC 2015 x86_64 x86_64 x86_64 GNU/LinuxHere is the output of lsblk on the centos VM I'm playing with:lsblkNAME            MAJ:MIN RM  SIZE RO TYPE MOUNTPOINTsda               8:0    0   30G  0 disksda1            8:1    0  500M  0 part /bootsda2            8:2    0 29.5G  0 part  centos-root 253:0    0 27.5G  0 lvm  /  centos-swap 253:1    0    2G  0 lvm  [SWAP]sdb               8:16   0    1G  0 disksdb1            8:17   0  200M  0 partsdb2            8:18   0  200M  0 partsdb3            8:19   0    1K  0 partsdb4            8:20   0  523M  0 partsdc               8:32   0  1.2G  0 disksr0              11:0    1 60.8M  0 romNow I run df to look at my drives (excluding the cdrom):sudo df -T -h /dev/sd*Filesystem     Type      Size  Used Avail Use% Mounted ondevtmpfs       devtmpfs  912M     0  912M   0% /dev/dev/sda1      xfs       497M  186M  311M  38% /bootdevtmpfs       devtmpfs  912M     0  912M   0% /devdevtmpfs       devtmpfs  912M     0  912M   0% /devdevtmpfs       devtmpfs  912M     0  912M   0% /devdevtmpfs       devtmpfs  912M     0  912M   0% /devdevtmpfs       devtmpfs  912M     0  912M   0% /devdevtmpfs       devtmpfs  912M     0  912M   0% /devdevtmpfs       devtmpfs  912M     0  912M   0% /devI'm super confused about what df is showing me here.Why are their so many devtmpfs entries and why are they all the same size?Running df on every partition (except /dev/sda1) shows devtmpfs with a size of 912M
Having trouble making sense of the df command
centos;filesystems;partition;disk usage;udev
My guess is that you have at least that many sd* entries in /dev.Try checking it with something like:for devsd in $(ls -1 /dev/sd*); do echo  \n This is for:  $devsd && df -Th $devsd; done You'll likely have a devtmpfs listed for each one. If you want to get a better idea of what your hard disks are really doing, just leave off the path at the end.df -Th 