Re: [gentoo-user] ZFS formating

2013-11-01 Thread Douglas J Hunley
On Fri, Nov 1, 2013 at 9:48 AM, James  wrote:

> Is the latest version of SystemRescue the best media to use to format
> disks with ZFS? Caveats?
>

the latest gentoo live image has full zfs support on it


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[gentoo-user] ZFS formating

2013-11-01 Thread James
Hello,

>
 So after readaing quite a bit about ZFS, I still have some  simple
question(s). Can you install ZFS on a single drive?  Does that make sense
or is it "illogical/dumb" to do so?


Is the latest version of SystemRescue the best media to use to format
disks with ZFS? Caveats?


Last, after looking  at the thread from 17Sep2013, I have culled.
These bookmarks as the best resources to follow (any others?) :

http://wiki.gentoo.org/wiki/ZFS

Just emerge zfs and its depndancies. Special/additional Flags
recommended but not in the aforementioned  resource listing?

turn off readahead. ZFS' own readahead and the kernel's clash - badly.
set it with blockdev to 8 (for example). Doesn't turn it off. Just makes
it none-obstrusive.

Turn off kernel's readahead for a visible performance boon.

use noop as io-scheduler.


> Has anyone tried hardened and ZFS together?

I did - I had some problems, but I'm not sure if they were caused by the
combination of ZFS and hardened. There were some issues updating kernel and
ZFS (most likely due to ZFS on root and me using ~arch hardened-sources and
the live ebuild for zfs). There are some hardened options that are known to
be not working (constify was one of them but that should be patched now). I
think another one was HIDESYM.

There is a (more or less regularly updated blogpost by prometheanfire
(installation guide zfs+hardened+luks [1]). So you could ask him or ryao (he
seems to support hardened+zfs at least to a certain degree).


Very interesting! What I want to experiment with is Pentoo on ZFS and then
downloading all the sources to create a secure gentoo installation
(hardened)_ by using Pentoo-amd64-2013.0_RC1.9.iso as the starting point.
Since the pentoo-installer script does not offer ZFS (yet), I thought I'd
just use SystemRescue (systemrescuecd-x86-3.8.1.iso) to set up ZFS? I do not
need luks, for this test system.


I have recently stopped using the option to
built ZFS into the kernel as I ran into problems with vdevs reported as
corrupt on the system I was trying this on. They weren't corrupt and
mounted fine in System Rescue Cd with modules, and the problem
disappeared when I switched to modules.


Plan carefully how you are going to create the vdev's before you add
them to a pool. Precisely my point, on a single 2T drive, or should
I add (required) a second 2T drive for this experiment. After I get
this to work, I have a 4 drive system to set up for testing..

http://wiki.illumos.org/display/illumos/ZFS+and+Advanced+Format+disks

Ok, so I have a single 2T seagate, or a pair of seagate 2T or 4 Green
2T WD drives to use for testing.

I just thoght a single drive rig would be fastest until I correct all
of the missteps (if it can go wrong in an install, I'll find it).

Just do ashift=12 and you're good to go.

So to recoup, my twist is to use the latest Pentoo install media,
becuase it is streamlined and yeilds a hardened system on top
of ZFS.

Anyone, care to splice in comments, suggestions or clarifications before
I invest some days in this venture?

curiously,
James