Re: Prepping to install

["William A. Mahaffey III" <wam%hiwaay.net@localhost>]

On 05/16/15 21:16, Michael Parson wrote:
> On Wed, 13 May 2015, William A. Mahaffey III wrote:
> > On 05/13/15 13:14, David Brownlee wrote:
> > > On 13 May 2015 at 16:03, William A. Mahaffey III <wam%hiwaay.net@localhost> 
> > > wrote:
> > > > On 05/13/15 08:48, David Brownlee wrote:
> > > > > On 12 May 2015 at 16:01, William A. Mahaffey III <wam%hiwaay.net@localhost> 
> > > > > wrote:
> > > > > > On 05/12/15 02:32, David Brownlee wrote:
> > > > > > > On 11 May 2015 at 23:46, William A. Mahaffey III 
> > > > > > > <wam%hiwaay.net@localhost> wrote:
>
> <big snip>
>
> > > > > > > If you want to maximise space with some redundancy then as you say,
> > > > > > > RAID5 is the way to go for the bulk of the storage.
> > > > > > >
> > > > > > > A while back I setup a machine with 5 * 2TB disks with netbsd-6, 
> > > > > > > with
> > > > > > > small RAID1 partitions for root and the bulk as RAID5
> > > > > > >
> > > > > > > http://abs0d.blogspot.co.uk/2011/08/setting-up-8tb-netbsd-file-server.html 
> > > > > > >
> > > > > > > (wow, was that really four years ago) - in your position I might 
> > > > > > > keep
> > > > > > > one 1TB as a scratch/build space and then RAID up the rest.
> > > > > > >
> > > > > > > If you have time definitely experiment, get a feel for the 
> > > > > > > different
> > > > > > > performance available from the different options.
> > > > > > *Wow*, another fabulous resource. Your blog documents almost 
> > > > > > verbatim
> > > > > > what I
> > > > > > have in mind. I am going w/ 6 drives (already procured, 6 SATA3 
> > > > > > slots on
> > > > > > the
> > > > > > mbd, done deal), but philosophically very close to what you 
> > > > > > describe. 1
> > > > > > question: if you were doing this again today, would it be fdisk 
> > > > > > or GPT ?
> > > > > If I had >2TB drives it would be TB :) If not, I would still stick
> > > > > with fdisk. The complexity of
> > > > > gpt setup and wedge autoconfiguration is still greater than fdisk and
> > > > > disklabel. I know I'm going to have to move to it at some point, but
> > > > > I'm going to hold off until I need to
> >
> > I meant to ask earlier, what is TB ? I think I will stick to fdisk. I 
> > used
>
> TB == Terabyte, the next jump past gigabyte.  Modern hard drives have
> been available in > TB sizes for a while now, which really is kinda
> nuts.

Yeah, I knew what TB was, but in the context of the other reply, it 
sounded like an alternative to GPT or fdisk, that's what I was asking 
about ....

> > GPT for this box, apparently well supported & I found numerous very 
> > detailed tutorials on how to setup what I wanted, so I went w/ it. 
> > All is going fabulously there, BTW ....
>
> <snip>
>
> > > Separate swap devices will give the best performance, RAID1 or 5 will
> > > give robustness in the face of a single component failure. You pays
> > > your money... Of course, if you have dedicated partitions on the disk
> > > which you could RAID then you can even change your mind after install,
> > > swapctl off the swap, mess with the partitions and away you go (nerves
> > > of steve advised, though not required :)
> >
> > From a reliability/robustness stand-point, if I had a HDD failure, 
> > would I be able to reboot w/ 1 lost swap partition w/o intervention ? 
> > I'm thinking not ....
>
> Yes, you would be able to boot just fine.  When it comes to that part
> of the boot process, the OS would just find that it couldn't access
> that device and move on.  As long as the missing bits aren't needed
> for booting (the rest of /, for instance), then you'd be fine, you
> would just be short however much swap is no longer available due to the
> missing/inaccessible device.
>
> Spreading out your swap space across devices gives you an effective
> RAID0 swap, but since the bits in swap don't get re-used over reboots,
> you don't lose any data should a disk fail between reboots.  Not 100%
> sure what would happen if the disk fails while there is active swap
> going on though.


I'm pretty sure that would be a hard crash if swap was in use. I was 
more concerned about recovery after that crash.




--

	William A. Mahaffey III

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