How to allocate more space to rootfs?

Docky · 08-27-2012, 02:47 PM

This is my system on my current Debian box:

Code:

Filesystem      Size  Used Avail Use% Mounted on
rootfs          9.8G  2.5G  6.9G  27% /
/dev/root       9.8G  2.5G  6.9G  27% /
tmpfs           1.6G  340K  1.6G   1% /run
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs            10M     0   10M   0% /dev
tmpfs           3.4G     0  3.4G   0% /run/shm
/dev/md2        921G  7.1G  868G   1% /home

From here I see that rootfs only has 9.8GB, I would like to allocate it more space from /dev/md2 so that I can use more space outside of /home. How would I do this?

custangro · 08-27-2012, 02:57 PM

Quote:

Originally Posted by Docky

This is my system on my current Debian box:

Code:

Filesystem      Size  Used Avail Use% Mounted on
rootfs          9.8G  2.5G  6.9G  27% /
/dev/root       9.8G  2.5G  6.9G  27% /
tmpfs           1.6G  340K  1.6G   1% /run
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs            10M     0   10M   0% /dev
tmpfs           3.4G     0  3.4G   0% /run/shm
/dev/md2        921G  7.1G  868G   1% /home

From here I see that rootfs only has 9.8GB, I would like to allocate it more space from /dev/md2 so that I can use more space outside of /home. How would I do this?

Are you running LVM? Or some sort of filesystem that allows for growing/shrinking filesystems?

Run these commands...

Code:

pvs
vgs
lvs

And post the output

--C

Docky · 08-27-2012, 03:01 PM

Quote:

Originally Posted by custangro

Are you running LVM? Or some sort of filesystem that allows for growing/shrinking filesystems?

Run these commands...

Code:

pvs
vgs
lvs

And post the output

--C

Code:

[~] sudo pvs
[~] sudo vgs
  No volume groups found
[~] sudo lvs
  No volume groups found
[~]

SecretCode · 08-27-2012, 03:25 PM

Unless you are able to apply LVM, you would have to repartition /dev/md2 - back up ALL your data before doing this in case something goes wrong - and make a new partition.

Instead of just increasing the space for / you could mount one of the directories on another partition - such as /var.

Docky · 09-02-2012, 08:32 PM

Bump.

Quote:

Originally Posted by SecretCode

Unless you are able to apply LVM, you would have to repartition /dev/md2 - back up ALL your data before doing this in case something goes wrong - and make a new partition.

Instead of just increasing the space for / you could mount one of the directories on another partition - such as /var.

I can't repartition it as it's already in use. I just need to know how I can shrink /dev/md2 and increase the size of /.

chrism01 · 09-03-2012, 12:38 AM

What does

Code:

fdisk -l

show (lowercase L there)

Docky · 09-03-2012, 01:45 AM

Quote:

Originally Posted by chrism01

What does

Code:

fdisk -l

show (lowercase L there)

Code:

[~] sudo fdisk -l

Disk /dev/sda: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders, total 1953525168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x000c155b

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        4096    20482048    10238976+  fd  Linux raid autodetect
/dev/sda2        20482049  1952471040   965994496   fd  Linux raid autodetect
Partition 2 does not start on physical sector boundary.
/dev/sda3      1952471041  1953517568      523264   82  Linux swap / Solaris
Partition 3 does not start on physical sector boundary.

Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders, total 1953525168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x00025ed0

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1            4096    20482048    10238976+  fd  Linux raid autodetect
/dev/sdb2        20482049  1952471040   965994496   fd  Linux raid autodetect
Partition 2 does not start on physical sector boundary.
/dev/sdb3      1952471041  1953517568      523264   82  Linux swap / Solaris
Partition 3 does not start on physical sector boundary.

Disk /dev/md1: 10.5 GB, 10484645888 bytes
2 heads, 4 sectors/track, 2559728 cylinders, total 20477824 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x00000000

Disk /dev/md1 doesn't contain a valid partition table

Disk /dev/md2: 989.2 GB, 989178298368 bytes
2 heads, 4 sectors/track, 241498608 cylinders, total 1931988864 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Alignment offset: 3584 bytes
Disk identifier: 0x00000000

Disk /dev/md2 doesn't contain a valid partition table
[~]

I know there's two drives there, but I'm only using the first one as it's the only one I need (not even sure if the second one is mounted).

chrism01 · 09-03-2012, 04:45 AM

Ok, I'd like to see this

Code:

mdadm --detail /dev/md1

mdadm --detail /dev/md2

but it looks like you've got 2 x 1TB disks, sda+sdb, each split 3 ways

1. root - mirrored on both - md1 (sda1+sdb1)
2. home - mirrored on both - md2 (sda2+sdb2)
3. 2 x swap - not mirrored - sda3, sdb3

You can only shrink a partition from the top down ie from the farthest end, backwards towards the start, so shrinking /home to add space to '/' is not practical.
(On your disks, '/' comes physically before /home)

You can

1. backup & re-partition; actually not a bad idea, and you should be making backups anyway

2. it would be possible to shrink the /home partition and put eg /var on the new space.
Remember to shrink the fs first, then the RAID partitions ie sda2+sdb2.

You definitely must do a backup before you try this.

pan64 · 09-03-2012, 06:09 AM

yes, shrink /home first and create another partition. copy your data from / (or from /bin, /var ...) onto the new partition (the whole filesystem you want to put onto the new drive), reconfigure fstab. create mount points by renaming old /var. Take care about preserving all the permissions. All of these should be done by booting another OS (probably a CD). Reboot, check, and start over in case of error. You can safely restore the original state as long as you can restore the old fstab and /var (and other dirs).

Docky · 09-03-2012, 09:09 AM

Quote:

Originally Posted by chrism01

Ok, I'd like to see this

Code:

mdadm --detail /dev/md1

mdadm --detail /dev/md2

but it looks like you've got 2 x 1TB disks, sda+sdb, each split 3 ways

1. root - mirrored on both - md1 (sda1+sdb1)
2. home - mirrored on both - md2 (sda2+sdb2)
3. 2 x swap - not mirrored - sda3, sdb3

You can only shrink a partition from the top down ie from the farthest end, backwards towards the start, so shrinking /home to add space to '/' is not practical.
(On your disks, '/' comes physically before /home)

You can

1. backup & re-partition; actually not a bad idea, and you should be making backups anyway

2. it would be possible to shrink the /home partition and put eg /var on the new space.
Remember to shrink the fs first, then the RAID partitions ie sda2+sdb2.

You definitely must do a backup before you try this.

I'll need to look into that more before I re-partition anything. Here's the output of those commands:

Code:

[~] mdadm --detail /dev/md1
/dev/md1:
        Version : 0.90
  Creation Time : Mon Aug 27 06:02:17 2012
     Raid Level : raid1
     Array Size : 10238912 (9.76 GiB 10.48 GB)
  Used Dev Size : 10238912 (9.76 GiB 10.48 GB)
   Raid Devices : 2
  Total Devices : 2
Preferred Minor : 1
    Persistence : Superblock is persistent

    Update Time : Mon Sep  3 15:08:09 2012
          State : active 
 Active Devices : 2
Working Devices : 2
 Failed Devices : 0
  Spare Devices : 0

           UUID : 62fd2a8d:4fd0962f:a4d2adc2:26fd5302
         Events : 0.7

    Number   Major   Minor   RaidDevice State
       0       8        1        0      active sync   /dev/sda1
       1       8       17        1      active sync   /dev/sdb1
[~] mdadm --detail /dev/md2
/dev/md2:
        Version : 0.90
  Creation Time : Mon Aug 27 06:02:23 2012
     Raid Level : raid1
     Array Size : 965994432 (921.24 GiB 989.18 GB)
  Used Dev Size : 965994432 (921.24 GiB 989.18 GB)
   Raid Devices : 2
  Total Devices : 2
Preferred Minor : 2
    Persistence : Superblock is persistent

    Update Time : Mon Sep  3 15:08:07 2012
          State : clean 
 Active Devices : 2
Working Devices : 2
 Failed Devices : 0
  Spare Devices : 0

           UUID : e296cbcf:93113984:a4d2adc2:26fd5302
         Events : 0.30

    Number   Major   Minor   RaidDevice State
       0       8        2        0      active sync   /dev/sda2
       1       8       18        1      active sync   /dev/sdb2
[~]

aristocratic · 09-03-2012, 10:34 AM

In your original question, what command did you use to get this output? I am familiar with the fdisk -l command, but not the command you used.

Filesystem Size Used Avail Use% Mounted on
rootfs 9.8G 2.5G 6.9G 27% /
/dev/root 9.8G 2.5G 6.9G 27% /
tmpfs 1.6G 340K 1.6G 1% /run
tmpfs 5.0M 0 5.0M 0% /run/lock
tmpfs 10M 0 10M 0% /dev
tmpfs 3.4G 0 3.4G 0% /run/shm
/dev/md2 921G 7.1G 868G 1% /home

F

SecretCode · 09-03-2012, 11:19 AM

aristocratic, the OP output is from

Code:

df -h

Docky · 09-03-2012, 04:55 PM

Quote:

Originally Posted by aristocratic

In your original question, what command did you use to get this output? I am familiar with the fdisk -l command, but not the command you used.

Filesystem Size Used Avail Use% Mounted on
rootfs 9.8G 2.5G 6.9G 27% /
/dev/root 9.8G 2.5G 6.9G 27% /
tmpfs 1.6G 340K 1.6G 1% /run
tmpfs 5.0M 0 5.0M 0% /run/lock
tmpfs 10M 0 10M 0% /dev
tmpfs 3.4G 0 3.4G 0% /run/shm
/dev/md2 921G 7.1G 868G 1% /home

F

I used df -h

Code:

Filesystem      Size  Used Avail Use% Mounted on
rootfs          9.8G  7.9G  1.5G  85% /
udev             10M     0   10M   0% /dev
tmpfs           1.6G  1.4M  1.6G   1% /run
/dev/md1        9.8G  7.9G  1.5G  85% /
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs           3.4G  4.0K  3.4G   1% /run/shm
/dev/md2        921G   55G  820G   7% /home