[Discuss] How do you backup "/" with rsync?

[John Blomfield]

John Blomfield wrote:
> Hi Mike,
> Incidentally, rsync -a --delete --exclude=external_backup/*** 
> --exclude=dev/***  /  /external_backup will work I just run a test 
> using two separate exclude options.
> The -x option will only be useful to Alan if all his subdirectories 
> below root / are on the same partition which is likely not the case 
> e.g. perhaps /boot and /home at least are on separate partitions.
>
> OK, I understand that usbfs or tmpfs are device names that can be 
> assigned to external physical file systems that might be temporarily 
> attached to your computer. e.g. inserting a pen drive or cdrom etc.  
> But what about /sys and /proc whose device name is "none"?  Also, only 
> /dev/pts that is mounted not the rest of /dev?  "none" must be some 
> system construct, i.e. a virtual file system, so how is that created?
>
> John Blomfield
>
> Mike O'Connor wrote:
>> Hi John
>>  
>>> I had always associated a file system with a physical entity i.e. a
>>> partition but now that you point it out, proc, sysfs and devpts are
>>> mounted in the /etc/fstab at /proc /sys and /dev/pts but I don't
>>> really understand this, since they are not associated with a physical
>>> partition.  I know /proc is referred to as a virtual file system but I
>>> hadn't realised it would behave like a physical file system. Are /sys
>>> and /dev/pts etc. also virtual file systems? How do you define or
>>> create a virtual file system? Perhaps you could explain all this?
>>>     
>>
>> Anything which shows up in /proc/mounts is a separate file system. As to
>> creating them its just a case of mounting the file system you need, ie
>> tmpfs, ramfs, or any other one you might need, some like the usbfs is
>> mounted by other systems as needed.
>>
>> vmapps1:~# cat /proc/mounts
>> rootfs / rootfs rw 0 0
>> none /sys sysfs rw 0 0
>> none /proc proc rw,nodiratime 0 0
>> udev /dev tmpfs rw 0 0
>> /dev/disk/by-label/ROOTFS / ext3 rw,noatime,data=ordered 0 0
>> /dev/disk/by-label/ROOTFS /dev/.static/dev ext3 rw,data=ordered 0 0
>> tmpfs /lib/init/rw tmpfs rw,nosuid 0 0
>> usbfs /proc/bus/usb usbfs rw,nosuid,nodev,noexec 0 0
>> tmpfs /dev/shm tmpfs rw,nosuid,nodev 0 0
>> devpts /dev/pts devpts rw,nosuid,noexec 0 0
>> tmpfs /rw tmpfs rw 0 0
>> /dev/sda2 /var/lib/vservers ext3 rw,data=ordered 0 0
>> /dev/sda2 /vservers ext3 rw,data=ordered 0 0
>> /dev/sda2 /etc/vmware ext3 rw,data=ordered 0 0
>> /dev/sda2 /usr/lib/vmware ext3 rw,data=ordered 0 0
>> /dev/sda2 /usr/lib/vmware-mui ext3 rw,data=ordered 0 0
>> /dev/sda2 /usr/lib/vmware-server-console ext3 rw,data=ordered 0 0
>> /dev/sda2 /usr/src/linux ext3 rw,data=ordered 0 0
>>
>>
>> /etc/fstab
>> vmapps1:~# cat /etc/fstab
>> #/dev/hda1       /       ext2    defaults,noatime,rw     0       0
>> proc            /proc   proc    defaults                0       0
>> tmpfs           /rw     tmpfs   defaults,size=500M        0       0
>> LABEL=SWAP      none    swap    pri=1                   0       0
>> LABEL=VSERVERS          /var/lib/vservers                       
>> ext3   defaults,rw     0       0
>> /var/lib/vservers       /vservers                               
>> none   defaults,bind   0       0
>> /var/lib/vservers/vmware/vmware-etc     /etc/vmware             
>> none   defaults,bind   0       0
>> /var/lib/vservers/vmware/vmware-server  /usr/lib/vmware         
>> none   defaults,bind   0       0
>> /var/lib/vservers/vmware/vmware-mui     /usr/lib/vmware-mui     
>> none   defaults,bind   0       0
>> /var/lib/vservers/vmware/vmware-server-console 
>> /usr/lib/vmware-server-console  none    defaults,bind   0       0
>> /var/lib/vservers/vmware/vmware-linux   /usr/src/linux          
>> none   defaults,bind   0       0
>>
>>
>>   
>
>