Debian hell :-)

[Jamon Camisso]

On 20/05/13 04:28 PM, David Mason wrote:
> I finally went and did it...
> 
> Picked up 4 new 1TB drives + SSD + new MOBO (needed 6 SATA ports) +
> new CPU (Athlon II X3) and (after many frustrating hours) I'm mostly
> happy... ($650 lighter, but happy).
> 
> except, the whole reason to do this was to get ZFS, and
> http://zfsonlinux.org/debian.html has a simple couple steps to do, and
> everything would be fine... except, it works on amd64, not x86 and
> this system was previously an Atom, so I had it as x86.

Careful with the SSD & ZFS (and Linux). You definitely don't want swap
on it, and minimizing the number of writes is something to work toward.
If you get your SSD into your zpools without noticing, you can wear out
the drive unless you use it intentionally.

> It took me a long time to figure this out.
>           apt-get install debian-zfs
> politely says:
>     Package debian-zfs is not available, but is referred to by another package.
>     This may mean that the package is missing, has been obsoleted, or
>     is only available from another source
> 
>     E: Package 'debian-zfs' has no installation candidate
> 
> Eventually, I figured out that this meant that it is not available FOR
> THIS ARCH!  In the meantime, I wondered if I'd set up the sources.list
> wrong, or had a corrupt apt database, etc.
> 
> So now I need to move to amd64.  I found a convient page:
> http://wiki.debian.org/Migrate32To64Bit but the first step is to
> download a 64-bit kernel, so I try:
>         apt-get install linux-image-3.2.0-4-amd64
> with similar results to before.  So I try
> http://packages.debian.org/wheezy/linux-image-amd64 to download, but
> the file it points to is 5Kb long.

Here's the package that you wanted: the link above is a meta-package
that always ensures the latest version of the kernel is installed.

http://packages.debian.org/wheezy/linux-image-3.2.0-4-amd64

> Sigh... I like debian, I really do, but there's sometimes too much
> magic going on for those of us who only actually poke at it every few
> months.
> 
> Thanks for any guidance.  I'd really like to get this running.  (And
> I'd like to install parted, but I get the same message there as
> before).

You'd have this issue with any distro trying to upgrade from 32 to 64bit
in place. Here's my suggestion in general steps (do a backup, and plan
each step first!):

dpkg --get-selections > /media/USB-STICK

Now you have two options: since you have a backup, boot a Debian
installer and do a clean install, or; boot up a livecd, rm everything
except /etc /home /opt /var (any other locations that you use, leave in
place.

Boot the Debian installer. If you are going to restore from your backup,
wipe your target disk. If you are installing in place, DO NOT FORMAT THE
EXISTING DISK (but you have a backup anyways).

I'm guessing you want to install to the SSD, in which case point the
installer there. Don't partition it with swap unless you plan to limit
your system's use thereof somehow. Put your swap on a spinning disk
unless you know what you're doing.

Important in the installer is that you choose the default for packages
(don't select any). You can leave your TB disks alone for ZFS since
you'll use zpool to handle those.

Boot up the new install, update all the packages using apt-get/aptitude.
Then the magic:

dpkg --set-selections < /media/USB-STICK
apt-get -u dselect-upgrade

The last part will take the list of packages from your old 32bit
version, and then run apt-get to install packages until the new system
matches those packages specified.

Search around a bit for strategies on using dpkg --get and
--set-selections.

I think you'll find a clean install to the SSD and then a quick restore
from your backup of any data is easiest. After all you have a SATA2/3
motherboard, it won't take long, and you are guaranteed with a nice
clean new 64bit system for ZFS ;)

(Question: how much ram do you have for this system? If you use
deduplication you're looking at 6-8GB  per TB of data depending on your
read/write ratio. Something to keep in mind. Stick with compression
first, get a handle on that and see if it fits your needs, then if
you're interested and have a use case, try dedup)

More good reading here:
http://pthree.org/2012/12/04/zfs-administration-part-i-vdevs/

And here http://www.cuddletech.com/blog/pivot/entry.php?id=983

Jamon

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