How can I allocate more space to my root partition?

[sazzadhussein]

My Ubuntu machine's root partition is above 80% full.

xxxx@dberc-repo:~$ df -h
Filesystem Size Used Avail Use% Mounted on
udev 79G 12K 79G 1% /dev
tmpfs 16G 1.3M 16G 1% /run
/dev/mapper/dell--dev--02--vg-root 117G 88G 24G 80% /
none 4.0K 0 4.0K 0% /sys/fs/cgroup
none 5.0M 0 5.0M 0% /run/lock
none 79G 7.0M 79G 1% /run/shm
none 100M 0 100M 0% /run/user /dev/sda1 236M 100M 124M 45% /boot

But I can still see that, there are some other partitions (/run/shm or /run), which have space to spare.
Can anyone suggest how I can allocate some of the free space to my root partition?

[darkod]

Those do not seem like partitions. The /run/shm is the mount point, the partition name would be the first column and that says 'none'.

How big is your hdd?

Please post the output of:

sudo parted /dev/sda unit MiB print
sudo vgdisplay
sudo lvdisplay

[ajgreeny]

I wonder if you are using LVM partitioning for your system?

Please show the output of command mount in code tags.
Please use Code-Tags for terminal output. See my signature below for a How-to

[sazzadhussein]

Hi Darko,
Please find the output here in bellow:

xxx@dberc-repo:~$ sudo parted /dev/sda unit MiB print[sudo] password for xxx:
Model: DELL PERC H730 Mini (scsi)
Disk /dev/sda: 285568MiB
Sector size (logical/physical): 512B/512B
Partition Table: msdos


Number Start End Size Type File system Flags
1 1.00MiB 244MiB 243MiB primary ext2 boot
2 245MiB 285567MiB 285322MiB extended
5 245MiB 285567MiB 285322MiB logical lvm




xxx@dberc-repo:~$ sudo vgdisplay
--- Volume group ---
VG Name dell-dev-02-vg
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 3
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 2
Open LV 2
Max PV 0
Cur PV 1
Act PV 1
VG Size 278.63 GiB
PE Size 4.00 MiB
Total PE 71330
Alloc PE / Size 71330 / 278.63 GiB
Free PE / Size 0 / 0
VG UUID QKd7dj-o2Y4-d3Cg-zZds-ro5A-kkaV-CJkTo1


xxx@dberc-repo:~$ sudo lvdisplay
--- Logical volume ---
LV Path /dev/dell-dev-02-vg/root
LV Name root
VG Name dell-dev-02-vg
LV UUID 9aaEVd-0RDp-9PFB-gubx-4zwa-0Me0-CdCYo7
LV Write Access read/write
LV Creation host, time dell-dev-02, 2015-08-31 18:51:27 +0200
LV Status available
# open 1
LV Size 118.73 GiB
Current LE 30394
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 252:0

--- Logical volume ---
LV Path /dev/dell-dev-02-vg/swap_1
LV Name swap_1
VG Name dell-dev-02-vg
LV UUID f10YZd-QrB6-71RY-WL5y-gbAz-G0Mx-L7cNXi
LV Write Access read/write
LV Creation host, time dell-dev-02, 2015-08-31 18:51:27 +0200
LV Status available
# open 2
LV Size 159.91 GiB
Current LE 40936
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 252:1

[sazzadhussein]

Hi ajgreeny,
It's a LVM partitioning system.

xxx@dberc-repo:~$ sudo fdisk -l

Disk /dev/sda: 299.4 GB, 299439751168 bytes
255 heads, 63 sectors/track, 36404 cylinders, total 584843264 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000e9776


Device Boot Start End Blocks Id System
/dev/sda1 * 2048 499711 248832 83 Linux
/dev/sda2 501758 584841215 292169729 5 Extended
/dev/sda5 501760 584841215 292169728 8e Linux LVM


Disk /dev/mapper/dell--dev--02--vg-root: 127.5 GB, 127481675776 bytes
255 heads, 63 sectors/track, 15498 cylinders, total 248987648 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000


Disk /dev/mapper/dell--dev--02--vg-root doesn't contain a valid partition table


Disk /dev/mapper/dell--dev--02--vg-swap_1: 171.7 GB, 171698028544 bytes
255 heads, 63 sectors/track, 20874 cylinders, total 335347712 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000


Disk /dev/mapper/dell--dev--02--vg-swap_1 doesn't contain a valid partition table

[darkod]

As it is, you can't expand the root LV. If you check the vgdisplay "Free PE" value, it says 0 free extents.

This is because you made swap LV too big. Check the lvdisplay output. You assigned 118GB for root LV and 160GB for swap LV.

That is way too much for swap. Usually for swap you need around 1.5 x the amount of memory, and sometimes even that is too much.

You need to unmount swap temporarily (swapoff) and reduce the swap LV. That will give you free extents in the VG and you can expand the root LV.

If you need exact commands for all that, ask, but google has enough tutorials of LVM procedures.

[sazzadhussein]

Thank you for your quick reply!
I'm going to drill down from google first & prepare a procedure first.
Then i will upload the document & may be you will have a short overview on that?
Just need to make sure everything goes well.
I'll get back to you very soon!

[sazzadhussein]

Worth to be mention, i just have checked that the machine is having 157GB of RAM:


sysadm@dberc-repo:~$ free -g total used free shared buffers cached
Mem: 157 96 60 0 0 80
-/+ buffers/cache: 15 141
Swap: 159 0 159

So, do you think it's ok get space from the swap partition?
As swap is allocated almost same space as the RAM on that machine!

[darkod]

The rule about swap and RAM is approximate and the more RAM you have the less probability swap to be used at all. That's why in your case with 157GB of RAM it doesn't mean you need 160GB of swap.

In fact, the beauty of LVM is that you don't need to extend any LV unless it is really necessary. Your root LV still has 20% free which is not little. So what you can do is this:
1. Shrink the swap LV to 32GB for example.
2. Leave the free space as free in the VG, no need to extend the root LV.
3. If in the future you see that you need more swap, you can assign part of the free space to it. And another part to the root.

But don't assign everything right away. In LVM you assign as much as you need and keep the rest available. That avoids situations like the one you have now. root which is 80% full and big swap that is not even being used at all.