How to restore the server using the rescue system (older systems)

The Rescue System is a Linux system that runs on a RAM-Disk. A connection with 

your Root-Server will look something like this (with your IP address instead of 172.17.1.1):



user@machine:~$ ssh root@172.17.1.1

Password: XXXXX

Welcome to pureserver rescue disk



If you are using a unix/linux/mac from a terminal.  If you are using a windows machine you will 



need to connect with an ssh client such as putty.



Remote Server Access Using Secure Shell (SSH)
                        

                            

From here you can partition your internal hard drive or edit incorrect settings.

The following is the standard partitioning of the internal hard drive:



root@pureserver-rescue:~# fdisk -l

Disk /dev/hda: 16 heads, 63 sectors, 58168 cylinders

Units = cylinders of 1008 * 512 bytes

                                           

Device Boot    Start       End    Blocks   Id  System

/dev/hda1             1        66    530113+  83  Linux

/dev/hda2            67       321   2048287+  82  Linux swap

/dev/hda4           322      5005  37624230    5  Extended

/dev/hda5           322       959   5124703+  83  Linux

/dev/hda6           960      1597   5124703+  83  Linux

/dev/hda7          1598      5005  27374728+  83  Linux

root@pureserver-rescue:~#

                            

First of all you should run a filesystem check to fix any errors in the file 

structure.




                          
Please note
                          
!Do not run file system repairs on partitions that are mounted as this will destroy the data!
                        
                        



rescue:~# fsck /dev/hda1



hda5, hda6, and hda7 are XFS and use different methods to be checked.



rescue:~# xfs_check /dev/hda5

rescue:~# xfs_check /dev/hda6

rescue:~# xfs_check /dev/hda7



If the curser simply returns to the 



rescue:~#



then there were no detectable problems.  If this does report errors you will first want to mount and umount the drives.  Replace x with the partition that 



reported an error.



rescue:~# mount /dev/hdax /mnt

rescue:~# umount /dev/hdax 



Then check the partition again.  If there are still problems with 5, 6, or 7 you will need to run xfs repairs on these partition.  Using the -L option does 



run the risk of data loss so it is recommended that you use this option if you have backups of the data or the data is already irretrievable.



rescue:~# xfs_repair -L /dev/hdax

                            

Now you can mount the internal hard drive into the /mnt directory and change into 

the system on the partition:



rescue:~# mount /dev/hda1 /mnt

rescue:~# mount /dev/hda5 /mnt/usr 

rescue:~# mount /dev/hda6 /mnt/var 

rescue:~# mount /dev/hda7 /mnt/home



One of the things you can check here is:



ensure that the partitions are not full with 



rescue:~# df -h

Filesystem            Size  Used Avail Use% Mounted on

/dev/ram0             252M  218M   34M  87% /

tmpfs                 998M  4.0K  998M   1% /dev/shm

/dev/hda1              950M  137M  765M  16% /mnt

/dev/hda5              4.7G  2.1G  2.6G  46% /mnt/usr

/dev/hda6              4.7G  4.4M  4.7G   1% /mnt/home

/dev/hda7              221G  111M  221G   1% /mnt/var



if any of these 



/dev/hda1              950M  137M  765M  16% /mnt

/dev/hda5              4.7G  2.1G  2.6G  46% /mnt/usr

/dev/hda6              4.7G  4.4M  4.7G   1% /mnt/home

/dev/hda7              221G  111M  221G   1% /mnt/var



are at or near 100% this will cause problems and you will want to remove data to create more free space.  You can search for large files with the find 



command.  So if the /mnt/var partition is full you would use 



rescue:~# find /mnt/var -size +1000M



to search for files larger then 1000MB.  If you do not find anything decrease the size to 750M and look again.



Now you can repair and/or configure your Root-Server in /mnt



So if you need to make a proper database dump of your mysql databases you could start mysql



rescue:~# /etc/init.d/mysqld start




                          
Please note
                          
Remember you are running the everything out of the RAM and so have less memory to work with then normal.  So start as few services as possible to accomplish what you need to accomplish.
                        
                        

  

After you have finished restoring your root server you need to execute the 

following commands to restart your Root-Server:



to exit the chroot environment



rescue:~# exit



umount the file system



rescue:~# umount -al



Do not forget to unmount your internal hard drive after the restore and BEFORE you 

restart the server. Also remember to change your Root-Server back to normal boot 

mode from your Control Panel.  You have the option of rebooting from inside the recovery tool or just chaning the boot image by either selecting the reboot 



now option or not.  If you do not select the reboot now option it will only change the boot mode.



rescue:~# shutdown -r now