"df -h" Question

Spetsnaz · 04-13-2013, 02:55 PM

In my dedicated server I only need 2 partitions but I am not sure why so many were created.
I am using OVH dedicated server so maybe thats why.
This is my "df -h" output

Code:

[root@ns4002250 ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
rootfs                 20G  753M   18G   4% /
/dev/root              20G  753M   18G   4% /
none                  7.8G  456K  7.8G   1% /dev
/dev/mapper/vg-lv1    1.8T  196M  1.7T   1% /kvm
tmpfs                 7.8G     0  7.8G   0% /dev/shm
/dev/root              20G  753M   18G   4% /var/named/chroot/etc/named
/dev/root              20G  753M   18G   4% /var/named/chroot/var/named
/dev/root              20G  753M   18G   4% /var/named/chroot/etc/named.conf
/dev/root              20G  753M   18G   4% /var/named/chroot/etc/named.rfc1912.zones
/dev/root              20G  753M   18G   4% /var/named/chroot/etc/rndc.key
/dev/root              20G  753M   18G   4% /var/named/chroot/usr/lib64/bind
/dev/root              20G  753M   18G   4% /var/named/chroot/etc/named.iscdlv.key
/dev/root              20G  753M   18G   4% /var/named/chroot/etc/named.root.key
[root@ns4002250 ~]#

This will be a KVM server and I think I only need this part

Code:

rootfs                 20G  753M   18G   4% /
/dev/root              20G  753M   18G   4% /
none                  7.8G  456K  7.8G   1% /dev
/dev/mapper/vg-lv1    1.8T  196M  1.7T   1% /kvm

But how do I remove the rest of the partitions and add it to "/dev/mapper/vg-lv1"

btmiller · 04-13-2013, 03:34 PM

All the partitions name /dev/root aren't real on disk partitions. They look like bind mounts related to the operation of the BIND DNS server (named), which typically runs in a chroot jail for security reasons (in this case the jail is in /var/named/chroot). If you look at these partitions, you can see they have exactly the same usage % as your root filesystem (in fact /dev/root is your root filesystem). These are just pseudo-partitions for the name server (been awhile since I had to run BIND, so I'm not sure why things are set up this way). They are not costing you any space you would otherwise have. Also, you do need /dev/shm as well, but it's an in memory filesystem like /dev itself -- again, it's not costing you anything.

Spetsnaz · 04-13-2013, 03:39 PM

Quote:

Originally Posted by btmiller

All the partitions name /dev/root aren't real on disk partitions. They look like bind mounts related to the operation of the BIND DNS server (named), which typically runs in a chroot jail for security reasons (in this case the jail is in /var/named/chroot). If you look at these partitions, you can see they have exactly the same usage % as your root filesystem (in fact /dev/root is your root filesystem). These are just pseudo-partitions for the name server (been awhile since I had to run BIND, so I'm not sure why things are set up this way). They are not costing you any space you would otherwise have. Also, you do need /dev/shm as well, but it's an in memory filesystem like /dev itself -- again, it's not costing you anything.

Thank you for explaining everything and thank you.
But my last thing is
how come there is only 1.7TB on /dev/mapper/vg-lv1 when I was doing partitioning on OVH it had 1.9TB.

btmiller · 04-13-2013, 04:15 PM

The filesystem uses a bit of extra space to hold things like inodes and other metadata. There's also some space reserved for root (5% by default IIRC). This probably accounts for the slight discrepancy.

btmiller · 04-13-2013, 04:15 PM

The filesystem uses a bit of extra space to hold things like inodes and other metadata. There's also some space reserved for root (5% by default IIRC). This probably accounts for the slight discrepancy.

Spetsnaz · 04-13-2013, 04:19 PM

Quote:

Originally Posted by btmiller

The filesystem uses a bit of extra space to hold things like inodes and other metadata. There's also some space reserved for root (5% by default IIRC). This probably accounts for the slight discrepancy.

I see.
Thank you very much BTMiller for the answers. Very helpful.
I was just a bit worried why I only had 1.7TB allocated on a section.
But now I know.