[SOLVED] Shrinking SWAP and ezpand ROOT

Alvin88 · 03-16-2012, 04:58 AM

Hi all,

I am new here, so first of all - Hello, everybody.

My issue is as follows:
I got Linux CentOS 6.2 istalled on SSD, which is 60 GB. However, the allocation is as follows:
- 26G - is root /
- 12G - home
- 17G - swap

What i would like to do is shrink swap to about 2G, and expand root /, with remaining 15G.

What i have done so far is:
- shrink swap file - I use an instruction which I have found on the Net
cat /etc/fstab | grep swap
lvdisplay /dev/mapper/VolGroup-lv_swap
swapoff /dev/mapper/VolGroup-lv_swap
lvresize /dev/VolGroup/lv_swap -L 2G
mkswap /dev/VolGroup/lv_swap
swapon /dev/VolGroup/lv_swap

The result is as:
lvdisplay /dev/mapper/VolGroup-lv_swap
--- Logical volume ---
LV Name /dev/VolGroup/lv_swap
VG Name VolGroup
LV UUID kGtj3Z-P9ke-tgrc-58hD-OBLe-zRmN-T8kRH4
LV Write Access read/write
LV Status available
# open 1
LV Size 2.00 GiB - it was 17.5 GB before
Current LE 512
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:1

So, i got 15.7G free:
pvscan
PV /dev/sda2 VG VolGroup lvm2 [55.41 GiB / 15.70 GiB free]
Total: 1 [55.41 GiB] / in use: 1 [55.41 GiB] / in no VG: 0 [0 ]

Now the question is - how can I add those 15 GB to root /?
If i missed something, or you need more info - please do not hesitate to ask/point that.

druuna · 03-16-2012, 05:02 AM

Hi,

Have a look here: LVM Resizing Guide

Hope this helps.

acid_kewpie · 03-16-2012, 05:05 AM

is / an LV? if so, then sure, it's really simple. use lvresize to increase the LV to use the rest of the free extents and then from a rescue disk or other mechanism whereby you have the / filesystem not mounted, you can then use resize2fs to make the ext2/3/4 filesystem fit the LV.

If / is NOT an LV, then it's a whole heap more tricky, and a better option may be to make a new LV and migrate some part of / onto it, e.g. /usr or /var

Satyaveer Arya · 03-16-2012, 05:17 AM

I haven't tried this, but it seems to me that one workaround you could do is to boot off another source(e.g. live CD), replace the swap partition with a regular one, shrink, and then make it back into a swap partition. After you package it up, make sure it works(so you avoid potentially touching the swap space before you compress it).

Do this as the very last thing before distributing (X windows and all other apps should not be running).

Code:

# swapoff -a
# shred -n 0 -z /dev/sdaXX  # (sdaXX is your swap partition)
# mkswap /dev/sdaXX         # recreate the swap format
# halt

to do it on every shutdown:
edit /etc/init.d/umountfs (at least in ubuntu)
After "swapoff" add:

Code:

# shred -n 0 -z /dev/sdaXX # zero out partition
# mkswap /dev/sdaXX        # recreate swap format

acid_kewpie · 03-16-2012, 05:20 AM

that's not what they asked, swap is already sorted.

Alvin88 · 03-16-2012, 05:42 AM

Many thanks for your help, the link provided by druuna was really helpfull on that occasion.

... and I must say that I am really suprosed by the speed of your response...

Many thanks for your help - and have a great weekend.

druuna · 03-16-2012, 05:46 AM

We are a fast bunch, aren't we......

And: You're welcome

BTW: Can you put up the [SOLVED] tag.
first post -> Thread Tools -> Mark this thread as solved