[mdlug] More new hard drive details

[Aaron Kulkis]

Drew wrote:
> The disk seems, as far as I can tell, good, so I'm going ahead. Some 
> additional questions I'd like
> to field before I begin however. I've decided that I want multiple 
> distributions, with the collected data
> that is not actually part of any distribution (in effect, everything 
> in /usr/downloads, /usr/iso, and maybe
> /usr/vdisks)


make that /local/downloads, /local/iso, and /local/vdisks.

/usr has a specific purpose, which is part of the distribution
/local has a specific purpose -- files which you add to customize
your installation which are not appropriate for /opt.

Then, whichever distribution your boot into, /local will contain
the same set of files with NO COPYING OR DUPLICATION.

> copied over to one or more partitions assigned roughly 
> half of the new drive (about 160 GB),
> with the other 160 GB being split into a partition for each installed 
> distro. Each distro will then have
> its own /home/drew replaced with, or contain, a symlink to the copied data.
> 
> First off, is it permissible for all these distributions to share a 
> common /tmp?

Yes.  In fact, at the GM tech center, there was an SGI network
attached storage (NAS) box which was providing a single /tmp
filesystem to TWENTY different computers simultaneously (through
NFS, network filesystem)


> If so, should the /tmp
> be cleaned out on boot? On shutdown?

It's not necessary.  I usually set up my system to have
cron run a job to remove all files that are older than a week.

> 
> Next, I've noticed that newer distros are showing my IDE drives as 
> sda, sdb, ... (for the hard drives)
> and sr0... for the DVD burner (and ISO images when booted in VMware). 
> A little research revealed
> that it's because the IDE driver is being merged with the SATA driver 
> as they want to reduce the
> amount of code they have to maintain. Also that you can still have 
> your disks named hda, hdb, ...
> but it requires compiling back in the old module. Someone at MDLUG 
> said there's a boot option
> that can force use of the old names.
> 
> * What is that boot parameter?
> * Is there a reason to go along with the all scsi standard?
> * Is there a reason to try to use the old names?

SCSI disks (sd) have 15 partition maximum
IDE disks (hd) have a 255 partition maximum

> 
> 
> Partition size: I'd like to optimize inode and space useage. Is it 
> worth while to have different partition
> sizes for different sizes of files, eg, a 100G partition for ISOs and 
> other big files, a 40G partition
> for medium sized files, and a 20G partition for small files? Or at 
> least different block size settings?

No.  Your chances of successfully "optimizing" your inode usage
is far smaller than leaving yourself with not enough inodes, and
then running out, leaving yourself with wasted disk space because
you can't create any more inodes on your system.  Inodes are both
small and cheap.  Just put all of those variously sized files in
the same filesystem (/local, as suggested above), and don't worry
about how much space your inodes use...it's a trivial amount.

> (I'm going with ext3 as I'm most sure of it being readable by all distros.)
> 
> Finally there's logical vs main partitions.

Create one primary partition which contains all of the disk space,
and then put logical partitions within the primary.

 As the distros themselves 
> are re-installable while the data
> needs better protection I had figured on going with main partitions 
> for data

It doesn't matter.  You're making this more complicated than it
is.  If you really want your data separated, then get another
device. Primary partitions are not any more of a physical
entity than the Logical Partitions held within an Extended Partition.

> and logical partitions on
> an extended for swap, /tmp, and all distros. I'm pretty sure grub can 
> handle it. However, the install

The only thing to remember is that swap space and /tmp can be shared
by all of your installed distros.  /tmp can even be shared by multiple
RUNNING copies simultaneously, but swap cannot.

> programs seem to have their own ideas on how to do this; they mostly 
> want to create all logical
> partitions on a single extended, with no other main partitions. Is 
> there a reason for going either
> way or even doing something different? What about LVM?

You're trying to do Masters-level work while still in your freshman year.

Learn the basics first, THEN go on to doing the advanced stuff.

Would you put a student driver in the Indy 500?


Of course not...he'd just get himself killed.