Move space from one ext3 parition to another

Tyir · 12-17-2003, 08:57 PM

In my slackware install, I have / as 5gigs, and /home as around 9 gigs, but i want to move some of the space back form /home to / since i dont have so much stuff in /home

Is there an eays way to move empty space from 1 partition to another, wihtout destroying any of the data?
I tried looking around in cfdisk, but it didn't seem like it could do that...

Thanks!

crabboy · 12-17-2003, 09:40 PM

Probably not since when resizing ext3 you can't change the starting block of the partition. So if / and /home were back to back on the hard drive, shrinking /home would not change the starting block of /home which still resides directly after the end of /. Does that make sense?

Post the output of 'df -k' and 'cfdisk -Ps /dev/hda'. See if we can get creative moving stuff around.

The Linux LVM allows you to resize logical paritions at will. I've used it for a couple years now and it keeps you from running into problems like this. http://www.sistina.com/products_lvm.htm

Tyir · 12-17-2003, 09:44 PM

Yes...that first part made perfect sense.....

Here is df -k

Code:

robert@MOFETTE:~$ df -k
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/hda4              4730632   3316280   1170164  74% /
/dev/hdb1               101089     16130     79740  17% /mnt/boot
/dev/hda5              9438216   1578188   7372860  18% /home
/dev/hdb2             19164900   5639256  12552108  31% /mnt/redhat
/dev/hda6               513028     83704    429324  17% /mnt/fatvital
/dev/hda7             53965120  32144800  21820320  60% /mnt/fatnonvital

As you can see, /home is well underused, and I would rather have more breathing room in /

Code:

root@MOFETTE:~# cfdisk -Ps /dev/hda
Partition Table for /dev/hda

               First       Last
 # Type       Sector      Sector   Offset    Length   Filesystem Type (ID) Flag
-- ------- ----------- ----------- ------ ----------- -------------------- ----
 1 Primary           0    20466809     63    20466810 HPFS/NTFS (07)       Boot
 3 Primary    20466810    21832334      0     1365525 Linux swap (82)      None
 4 Primary    21832335    31599854      0     9767520 Linux (83)           None
 2 Primary    31599855   160071659      0   128471805 W95 Ext'd (LBA) (0F) None
 5 Logical    31599855    51086699     63    19486845 Linux (83)           None
 6 Logical    51086700    52114859     63     1028160 W95 FAT32 (0B)       None
 7 Logical    52114860   160071659     63   107956800 W95 FAT32 (0B)       None

Is this LVM program free?

crabboy · 12-17-2003, 10:23 PM

Given you current setup. I'd probably convert /home into an LVM partition. On that new partition you can create a /home and another hog file systems from / on it. This would free up some space on /. And yes the LVM is free.[list=1][*]You can move the data off of /home with something like: tar -zcvf /home.tar.gz /home [*]Mark /dev/hda5 as a LVM partition in cfdisk.[*]Create a physical partition with: pvcreate /dev/hda5 [*]Then you create a volume group on that partition: vgcreate vg1 /dev/hda5[*]Next create a logical volume on the volume group: lvcreate -L1.6G -nhome vg1
Do this for each filesystem you want to mount on the LVM. Keep them as small as needed for now. You can enlarge them later.[*]Create a filesystem on each of the new logical volumes: mkreiserfs /dev/vg1/home
I like using reiserfs because I know it resizes well. You can also resize live file systems, although it may not be recommended to do so.[*]Mount the new filesystem on /home and update the entry in the /etc/fstab table:
/dev/vg1/home /home reiserfs defaults 1 1
[*]Extract the tar file back onto /home.[/list=1]

Make sure you understand everything above before you attempt it. Please ask questions if you have any. Also it may help to read the LVM howto on the sistina site.