Re: Making big ones out of little ones [was: tlug: Debian install...]

[Selva Nair <selva@example.com>]

On Fri, 21 Apr 2000 ulrike@example.com wrote:

>  > Dont think any step is missing in Stephen's example.
>  
>  I guess still have problems with simulating this with my biological, rather 
>  limited CPU. 
>  
>  > >  <stephen>
>  > >  
>  > >  Eg, I'm looking at a 1GB partition
>  > >  mounted on /usr, and that's just not going to cut it if Debian keeps
>  > >  adding packages at the current rate.  So I can add 33% free space to
>  > >  that partition by creating a 500MB partition somewhere (say
>  > >  /dev/sdb1), formatting it, mounting it to /tmp/share, copying
>  > >  /usr/share recursively to /tmp/share, then adding
>  > >  
>  > >  /dev/sdb1 /usr/share ext2 defaults 0 2
>  > >  
>  > >  to /etc/fstab, and doing `diff -rq /usr/share /tmp/share >
>  > >  /tmp/just-for-grins' to make sure everything's OK before doing rm -rf
>  > >  /usr/share; mkdir /usr/share; umount /tmp/share; mount /usr/share.
>  > >  
>  > >  </stephen>
>  
>  I thought after this  /usr/share is empty but mounted and /tmp/share is not 
>  available anymore including its data, but this is probably not the case, I am 

Better think in terms of physical disk partitions than those directory
names /usr/share and /tmp/share. You have all the data that appeared
below /usr/share moved to /dev/sdb1 which is presently not mounted. Now
mount it on /usr/share and you get the data on /dev/sdb1 accessible
below /usr/share as you originally had, but physically the data has
moved to a new partition i.e. /dev/sdb1. The example assumes that
/usr/share was initially a subdirectory within the partition mounted on
/usr and the idea is to move it to a new partition and mount that at
/usr/share so that the directory tree will be unaltered.

>  confused ... So by mounting empty /usr/share everything under /tmp/share is 
>  magically moved to /usr/share, since it is physically on /dev/sdb1? Or is this 

I think there you have got it right, though there is little magic 
in it ;)

>  the point after which I should move /tmp/share to /usr/share? But 
>  since /tmp/share is umounted, how will it be found? Or should I 
>  move  /tmp/share to /usr/share after having deleted the old /usr/share, instead 
>  of mkdir /usr/share? No, I guess somehow /tmp/share gets renamed by 
>  mounting /usr/share, is that correct?

Again, try changing the terminology a bit -- you dont mount /usr/share,
you mount something (in our case /dev/sdb1) *on* /usr/share. (Some
people may prefer to say mount *under* /usr/share )

>  
>  I will now test what yout wrote about swapping with a little adjustment 
>  since /var is full and there is still plenty of room on /usr ... if anything 

Finally dont end up with a tiny partition for /usr -- keep atleast 1MB
for /usr, unless you install only selected packages. What do you have on
/var to fill it up ?


Selva


>  goes wrong I just install everything from the beginning and mount it correctly 
>  from the start. But it's all very interesting .... taihen benkyoni narimashita.
>  
>  Arigatou, Uli


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