On 04/17/2012 06:40 PM, Frank Cox wrote:
> I mentioned here the other day that I was planning to set up a Centos 6 system
> using a SSD for the system drive and a regular hard drive for a data drive.
>
> My plan is to have everything that doesn't change (much) on the SSD, such
> as /boot, /lib, /bin and so on. I want to put /tmp and /var and /home on the
> regular hard drive.
>
> Now that I'm at the stage of actually setting this up I have discovered that I
> don't understand enough about drive partitioning to make this work the way that
> I want it to. Perhaps I'm missing something obvious.
>
> I could create separate partitions on the SSD for /lib, /bin and everything
> else that I want to put there, then put / on the hard drive, but I would really
> prefer to put /boot and one other partition on the SSD, and one partition on
> the hard drive.
You're going to find it very difficult to separate /lib and /bin from the
root file system. When the kernel starts up, it has just the root file
system. How can it execute the "mount" command to gain access to /lib
and /bin when the mount command and the libraries it needs are on a
file system that has not yet been mounted? It's far more straightforward
and more maintainable to put the root file system on the SSD and put
/tmp, /var, and /home on the regular drive.
Most writes to the root file system (other than root's home directory)
occur only during configuration changes (file system mounts/umounts,
network link starts/stops, modifying printers, ...) and much of that
could be moved off of the root file system with judicious use of
symlinks. I just now ran the 'find' command to see what on the root
file system had a time stamp more recent than the time of the last
boot (10 days ago, BTW) and filtering out root's home directory and
mount point directories and there was almost nothing. About the only
thing that would be any challenge to symlink away would be /etc/mtab,
and it's going to be awfully hard to wear out an SSD with a file
that gets written once for each mount or umount.
--
Bob Nichols "NOSPAM" is really part of my email address.
Do NOT delete it.