Disk Recovery Part III

[lug at the-leveys.us (Don Levey)]

discuss-bounces at blu.org wrote:
> Don Levey <lug at the-leveys.us> wrote:
>> I've partitioned one of them as follows ...
>
> This and a couple of the followups lead me to ask:  are you using the
> logical volume manager (lvm)?
>
> There are basically two ways to go about partitioning:  you can create
> separate primary partitions for each filesystem, or you can create
> one primary partition and use the logical volume manager to create
> logical volumes.
>
> You created four partitions plus swap so I have to ask--is there a
> good reason to make this any more complex than the bare essentials?
> The bare essentials would be a root, a /boot, and a swap.  I have
> reason to create a handful of separate volumes--to make my backups
> run a bit more efficiently and to ensure that runaway applications
> filling up a user filesystem won't starve the root fs of storage.
>
> I'm just asking this to prod you into some questions, because now's
> the time to simplify your setup if you can.
>
Rich,
I want to keep /home on a separate partition so that I can move/expand it if
necessary.  It also keeps the more changeable data away from the more static
data.  The /misc is so that I have a completely clean partition I can use
for whatever - including backups.  Then I've got /boot and / (and my /var is
on the RAID I've got now, as that's got my music and photos, website, etc).
In this particular case, having /home on its own partition meant that I
could just edit fstab and reboot and have the system running again, which is
useful when it's my mail and web server.

> Note that one of the niceties of the lvm tools is that you can leave
> some storage unallocated, and later add it only as necessary to
> whichever filesystem is running low on storage.  It's a feature that
> I discovered first on an RS6000 system running AIX and I used it to
> great advantage in a development shop where certain engineers tended
> to hog available space--I could resolve crises quickly and then go
> after the abusers later.  You won't run into this on a home system
> but you will still find lvm tools handy as your storage requirements
> change.  (Example, I keep music on one volume and still pictures on
> another--from time to time the collections' growth rate shifts from
> one to the other.)
>
I'll have to read up on this, as I don't know much about it.  Any favourite
pointers?

> You can, if necessary, mix & match multiple RAID partitions with lvm
> volumes. But the keep-it-simple strategy applies here:  only break
> things out into multiple partitions if the physical volumes are
> unavailable during an upgrade; once you've freed up a drive used to
> stage the upgrade, re-build the volumes and re-sync the arrays so
> everything is clean.
>
I'm not sure what you mean here - at this point, it's not an upgrade (yet)
but a repair.  The upgrade happens only when the system is stable again.
 -Don