Re: moving /var

[Claudius Hubig <debian_1303@chubig.net>]

Dear Maroš,

Maroš Žilka wrote:
> [root@server ~]# mkdir /new_var
> [root@server ~]# mount /dev/sdb1 /new_var
> [root@server ~]# cp -vrp /var/* /new_var/
> [root@server ~]# mv /var /old_var
> [root@server ~]# mkdir /var
> [root@server ~]# mount --bind /new_var/ /var
> 
> and what is really bothering me most is that cp command, wouldn't it
> possibly create inconsistency ? What would be better way to do it ? Is
> it even possible to do such change on running system without worries
> to lose some data ?

Yes - if someone writes to /var after the file was copied, this
change will be lost. You can make the window where such a change
would be lost smaller by running rsync twice:

# rsync -av /var/* /new_var
# rsync -av /var/* /new_var

where the second command should only take a few seconds (rather than
very long, if, for example, /var/www is large).

It might furthermore be helpful to remound /var read-only before the
procedure and shut down as many services as possible – if nothing
writes to /var, no data will be lost :)

Best,

Claudius
-- 
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