Re: [gNewSense-users] Mounting/partitioning inside a VM

[Kim Hawtin]

On 21/04/12 19:08, Stayvoid wrote:
> > Perhaps the first question is, why do you want to slice up the file
> > system in this way?
> >
> > I would consider it unusual to split off /tmp, /var, /var/tmp and
> > /var/mail in this way unless you were shifting a very large amount of mail.
> I use this guide:
> http://www.debian.org/doc/manuals/securing-debian-howto/ch4.en.html#s4.9
>
> > And then to separate disks, not all on the same volume/disk.
> Because I can't access the disk via fdisk or parted. I'll investigate
> this, but AFAICT it's a VPS specific issue.
> So the only option I have is to use several disks. I assume those are
> not separate in a physical sense.

If you can't use fdisk to label partitions, how are you adding these 
filesystems?

Are you running mke2fs on the raw disk device?

> > As you seem to be running a Xen VM, I would expect you are not going to
> > get a performance increase. It makes it much more likely that one of
> > these file systems is going to fill and halt which ever process that
> > doing the work in that file system.
> I'm trying to secure the system, not to get a perf boost. Let me know
> If I can achieve both.

You are running on a VPS.

Performance is not an option.

So keep it simple, otherwise it will be a complete arse to restore from 
backup.

> > Ok, for each new file system you will have to migrate them from the
> > 'root' disk/partition to the new disk/partition.
> Yep.
>
> >     2) mount each file system, eg under /tmp
> >     3) copy the data from the 'root' file system to the new one
> >        eg rsync -av /tmp/ /mnt/
> >     4) unmount the file system from /mnt
> This sounds strange. I will use my data if I unmount it. Is this correct?

No you will not lose the data. its on the new file system. which you 
then mount again in the right place.

> Maybe I should do the following:
...
> What do you think? Will it work?
> How to separate /var/mail from /var in this case?

Your idea of fresh disk is meaningless on a VPS. Short of making the 
collective file systems *larger*, there is no net gain, IMHO.

With a VPS you have to balance up the trade off between complexity and 
degrading performance. Adding more file systems degrades performance as 
memory usage only goes up. Even if you don't have much data in those 
file systems.

Why are you *actually* trying to do and why?

regards,

Kim