[plug] Advice wanted - come spend my money (vicariously)

[Richard Meyer]

Hi John

I chose sdc1 with no backup because I wasn't too worried about what I
kept there. I have one user with no WM who will manage everything and
everything worth anything will be on the RAID5 part, meaning that if
sdc1 goes pear-shaped, I replace sdc and rebuild, and start /home from
scratch. Of course I have to copy.ssh/ and a few other files to the
RAID5 area first, but that's not really a great problem ....

I was thinking of putting the OS on an ESATA disk or an SSD, but ran out
of money. I was also thinking of making all the sd*1 disks into a big
RAID0 disk wit a swap file, but that was too much like drinking 10
beers, eating a vindaloo and not wearing underpants the next day
(risky).

To be honest I was wondering about splitting swap across disks as well,
but then I would have had to make the / and /home partitions larger and
the swap smaller losing my symmetry over the disks.

Or maybe splitting each disk with two partitions on the front - say a
small swap of (say 5GB) and a set of RAID1's - one each for / and
for /home.

Since I wasn't sure that my original idea was going to work, I was
surprised (and gratified) when it did.

Thanks for the points.



On Tue, 2015-03-10 at 09:17 +0800, John McCabe-Dansted wrote:
> The only thing that seems odd to me is that you put  /home on  sdc1.
> Since /home could contain irreplaceable data, wouldn't /tmp be a
> better choice?
> 
> 
> 
> > Now my dilemma is is there a better filesystem I could use instead
> of
> XFS?
> 
> 
> I don't think there is an objectively correct answer to that question.
> We have an n40l and are thinking of putting everything on a single
> RAID10 formatted with ext4. This configuration would be better in the
> sense that it would be faster and more reliable than RAID5, but would
> only provide 4TB rather than 6TB. Unless you are doing some thing
> weird, either ext4 or XFS would probably be fine, I think.
> 
> 
> Some random comments:
>  - putting a swap partition on each drive would improve swap
> performance (though if any drive goes down you will have swap
> problems). This may also spread the load so sdd won't die so fast,
> which could be a good or bad thing depending on whether you want to
> use sdd as a canary.
> - Putting some ssd cache in front of the raid array, even USB, could
> improve performance. Of course if you are going to use writeback
> caching you would probably want a raid1 for the SSD cache so you don't
> have a single point of failure.
> -  if you put the OS on a (perhaps cheap) SSD you may be able to leave
> RAID powered down most of the time. This could reduce power
> consumption and rate of failures.
> 
> 
> 
> On Sun, Mar 8, 2015 at 9:34 AM, Richard Meyer
> <meyerri at gardenshark.org> wrote:
>         
>         Hi all
>         
>         I have one of those nice problems.
>         
>         I bought a "HP MicroServer G7 N54L AMD Dual Core 4GB ECC 4-Bay
>         NAS
>         Storage Server NO OS 1YRS" off Fleabay and have populated it
>         with a
>         small amount of storage and installed an OS -
>         
>              1. 4 x 2TB Seagate disks - would have preferred Hitachi,
>         but
>                 they're difficult to get here
>              2. Installed Ubuntu server (14.04)
>         
>         disks are partitioned as follows -
>         
>              1. 20GB clipped off the front of each disk (just to keep
>         them
>                 "similar")
>              2. sda1 and sdb1 are RAID 1, ext4 and contain /
>              3. sdc1 contains /home, ext4
>              4. sdd1 is swap space
>              5. sda2, sdb2, sdc2 and sdd2 are software RAID 5
>         formatted with XFS
>         
>         Now my dilemma is is there a better filesystem I could use
>         instead of
>         XFS?
>         
>         Since I haven't really got much going yet, now would be a good
>         time to
>         find out, before I have to move 5TB of pr0n around to reformat
>         the
>         disks.
>         
>         Can anyone suggest a better way of setting all this up?
>         
>         
>         --
>         Richard Meyer
>         
>         If my body is ever found on a jogging trail, just know
>         I was murdered elsewhere and dumped there.
>         
>         Linux Counter user #306629
>         
>         _______________________________________________
>         PLUG discussion list: plug at plug.org.au
>         http://lists.plug.org.au/mailman/listinfo/plug
>         Committee e-mail: committee at plug.org.au
>         PLUG Membership: http://www.plug.org.au/membership
> 
> 
> 
> 
> -- 
> John C. McCabe-Dansted
> _______________________________________________
> PLUG discussion list: plug at plug.org.au
> http://lists.plug.org.au/mailman/listinfo/plug
> Committee e-mail: committee at plug.org.au
> PLUG Membership: http://www.plug.org.au/membership

-- 
Richard Meyer

If my body is ever found on a jogging trail, just know 
I was murdered elsewhere and dumped there. 

Linux Counter user #306629