AddExtraHardDisk
Add extra harddisk
This HowTo are based on Michiel Blotwijk original.
Description
How to add an extra hard disk to an existing (running) SME server 7.x.
Assumptions
It assumes adding one PATA (IDE) harddrive as master on the second IDE controller, but the process will be similar in other situations. More on that in step 2.1.
The harddrive will be named bigdisk, this name will not be visible to the user.
You already have an ibay named mp3, this will be redirected to the new disk (together with its content). This name may be visible to the user (depending on the permissions).
You can replace the names bigdisk and mp3 with whatever valid name, just keep track of the names.
Step-by-step HowTo
1 Preparation
1.0 Mount the harddrive and fire up your machine.
1.1 Get direct shell access and login as root.
1.2 Tell init to go to single-user mode.
telinit 1
This will make you loose connection if you working tru an ssh-client (like Putty). You need direct access to the shell to proceed.
2 Partition
2.0 Now you need to identify the device name of the new disk.
The following command will show you all the drives on your server (including any USB drives you might have).
fdisk -l | more
| Role | IDE controller | Device name |
|---|---|---|
| Master | 1 | /dev/hda |
| Slave | 1 | /dev/hdb |
| Master | 2 | /dev/hdc |
| Slave | 2 | /dev/hdd |
2.1 Let's assume you installed the disk as master on the second IDE controller.
This means you have to partition /dev/hdc
fdisk /dev/hdc
and when prompted:
n (to add a new partition) p (to make a primary partion) 1 (that's the number one, the number you want to assign to the partition)
Accept the suggested first & last cylinder values
w (write and exit)
This will create the primary partition /dev/hdc1, using the entire disk space.
2.2 Format the new partition to ext3:
mkfs.ext3 /dev/hdc1
3 Mount
Create a mounting point for the new disk
A mounting point is just an empty directory that will link to your new disk.
This can be any valid directory on your server, but it is recommended not to use /home or one of its subdirectories.
In step 4 you will see a much better method to link your /home directory to the second disk.
3.0 Create a directory underneath /mnt
mkdir /mnt/bigdisk
3.1 Automount at boot time
To automatically mount the partition at boot time, you need to add the following line to the file /etc/fstab
It can be done in the text editor Pico
pico /etc/fstab
Add the following data to the file (separate columns with a hit on the space-bar):
/dev/hdc1 /mnt/bigdisk ext3 usrquota,grpquota 1 2
Make sure you end this line with a newline (with enter).
Hit <ctrl-x> to exit the editor, y and enter to save.
3.2 Mount manually (this time) all filesystems listed in /etc/fstab
mount -a
3.3 Report the amount of free disk space available on all mounted filesystems + the type of each filesystem, check if it looks OK.
df -T
Filesystem Type 1k-blocks Used Available Use% Mounted on /dev/hda3 ext3 39151724 28441348 8721532 77% / /dev/hda1 ext3 101089 8953 86917 10% /boot /dev/hdc1 ext3 38474956 27948 38447008 0% /mnt/bigdisk
If you don't see a line for /dev/hdc1, something went wrong.
Go back to step 2 and check if you followed all instructions correctly.
4 Mapping
4.0 Alternatives
Alternative 1: Use /home to mount the new disk
On standard Linux machines, the /home directory contains the user's directories and is therefore a popular place to mount a bigger disk.
However, on a SME server this is not a good idea:
SME stores all its configuration files in /home/e-smith/db.
If for whatever reason your disk doesn't mount, the configuration files will no longer be accessible, causing all kinds of nasty problems.
Mounting your second disk to /home or even /home/e-smith/files effectively means that your first disk will no longer be used to store user files.
In some cases that might be a good idea, but in most cases you are just wasting the remaining space of your first disk.
Alternative 2: A much better approach is to leave the second disk mounted at /mnt/bigdisk and to create symlinks (symbolic links) for specific ibays or user folders.
The following example shows you how to place the mp3 ibay on the second disk.
4.1 Create the necessary subdirectories on your second disk
mkdir -p /mnt/bigdisk/ibays/mp3
4.2 Check the ownerships and permissions on the original directory
ls -l /home/e-smith/files/ibays/mp3
drwxrwxr-x 18 admin allstaff 4096 Sep 23 14:48 mp3
4.3 Change ownership as in the original. The "-R" (optional) means recursive, subdirectorys will be included in the command.
chown -R admin:allstaff /mnt/bigdisk/ibays/mp3
4.4 Set permissions to the ibay mp3 as in the original. For help on this, look at bottom of this page. The "-R" (optional) means recursive, subdirectorys will be included in the command.
chmod 775 -R /mnt/bigdisk/ibays/mp3
4.5 Copy the content to your new disk
cp -rip /home/e-smith/files/ibays/mp3/* /mnt/bigdisk/ibays/mp3
4.6 Check if all files have been copied correctly
diff -r /mnt/bigdisk/ibays/mp3 /home/e-smith/files/ibays/mp3
4.7 Remove the original files
rm -rf /home/e-smith/files/ibays/mp3
4.8 Create a symlink to the new location
ln -s /mnt/bigdisk/ibays/mp3 /home/e-smith/files/ibays/mp3
4.9 Test the new location
ls /home/e-smith/files/ibays/mp3
4.10 If you want the ibay to be accessible from the internet, you also need to enable "follow symlinks" in apache:
mkdir -p /etc/e-smith/templates-custom/etc/httpd/conf/httpd.conf
echo Options FollowSymLinks >> /etc/e-smith/templates-custom/etc/httpd/conf/httpd.conf/85DefaultAccess
/sbin/e-smith/expand-template /etc/httpd/conf/httpd.conf
/etc/init.d/httpd graceful
5 Quota (optional)
Next you might want to activate the quota on the disk.
This will only work if you activated quota management for at least one user (Server Manager > Collaboration > Quota Management).
quotacheck -vugc /dev/hdc1
If you get "quotacheck: Old file not found" you probably haven't activated quota management.
If quotachecks comes back to the command prompt without errors, you're ready.
6 Final check
Reboot your machine
reboot
Check if the drive was mounted correctly with
df -T
and/or surf to your ibay.
If it looks fine, relax and tell the world about it, you made it!
Notes about RAID
- When you install SMEserver, ALL connected harddrives will be part of an RAID-array.
- When you add a drive to a running system, it will not take part of anything unless you do something about it. This is the case in this HowTo. Note that it will NOT take part in any RAID array and hence, get no redundancy.
- If you want the new drive to be part of an RAID array instead, get shell access, login as admin and select "5. Manage disk redundancy" and follow the instructions. The new disk should be empty and contain no partitions before doing this.
- For more info about RAID and disk management, take a look in the SME_Server:Documentation.
Notes about file permissions
The following are intended as help in the above situation.
This subject contains much more.
Basic style
--------- = 3+3+3 positions
Position
rwx------ = First set describes owner permissions
---rwx--- = Second set describes group permissions
------rwx = Third set describes user permissions
Permissons and positions in a set
r-- = read
-w- = write
--x = execute
3 digit style
000 = 3 positions
Position
n-- = owner
-n- = group
--n = user
Permission
read = 4
write = 2
execute = 1
Permissions are added together to a sum for one position.
Translate basic style to a 3-digit style
Position
First set = first digit = owner
Second set = second digit = group
Third set = third digit = user
Permission
r = read = 4
w = write = 2
x = execute = 1
Examples
--------- = 000 [owner=0+0+0][group=0+0+0][user=0+0+0] Nobody can do anything.
r--r--r-- = 444 [owner=4+0+0][group=4+0+0][user=4+0+0] Everybody can read.
-w--w--w- = 222 [owner=0+2+0][group=0+2+0][user=0+2+0] Everybody can write.
--x--x--x = 111 [owner=0+0+1][group=0+0+1][user=0+0+1] Everybody can execute.
rw-rw-rw- = 666 [owner=4+2+0][group=4+2+0][user=4+2+0] Everybody can read and write.
rwxr----x = 741 [owner=4+2+1][group=4+0+0][user=0+0+1] Owner can read, write and execute. Group can read. User can execute.
rwxrwxrwx = 777 [owner=4+2+1][group=4+2+1][user=4+2+1] Everybody can read, write and execute.
rwxrwxr-x = 775 [owner=4+2+1][group=4+2+1][user=4+0+1] Owner can read, write and execute. Group can read, write and execute. User can read and execute.
- For more help about chmod and file permissions, look at
ss64 or oreillynet.