[tech] More space on Molmol

[David Adam]

On Fri, 5 Aug 2016, Frames wrote:
> Ok, here is the deal with Molmol. We're running out space.  The situation is
> just below and the potential solutions are under that.
> 
>  * It has its book disk on an internal USB.
>  * It has its system disk on a 2.5inch SSD internally.
>      o Using 1 of its 4, motherboard SATA 3 (Black) ports
>  * It has 2 2.5 inch SDDs in raid for disk cache in the first 5.2inch bay,
>      o they are connected to its Motherboard SAS (White) ports (running
>        SATA3). There ports are not multiplexed -- that are endpoint
>        SAS, ie SATA ports

FYI, this is not quite right.

The pair of SSDs are partitioned into:
 * the bootloader (ada0p1 / ada1p1), 
 * the root filesystem (ada0p2 / ada1p2 as a GEOM mirror) 
 * the main drive array's SLOG devices (ada0p3 / ada1p3 as a ZFS mirror)
 * swap (ada0p4)

The other SSD is the L2ARC (ZFS cache) device. This came out of another 
machine and if it dies we can shrug and replace it.

The internal USB is someone's USB stick. I used it to update the firmware 
at some stage; it is not used in the boot process.

>  * It has piles of SATA 2 ports on the motherboard. Like 8 or so. These
>    are Blue.
>  * It has nothing in the bottom 5.2 inch bay, and it's fully accessible.
>      o *We could stick some hard drives of any description here *(may
>        be hard to get 2 x 3.5inches)
>      o And use any of the free connectors (prob SATA3 -- of which we
>        have 3 )
>  * It s 8 taken 2.5 inch bays (hotswappable), which match to 2 4x SAS
>    multipliers, which we have connected to the two ports on its SAS
>    card and we run SATA 3 through that.
>  * It has 8 free 2.5 inch bays (hotswappable), which match to 2 4x SAS
>    multipliers
>      o due to the physical nature of the SAS multiplexer (all 4,
>        multiplexer are on once card), we can probably not directly
>        connect those to SATA cable*** (more or less, see below)
> 
> That more or less summarizes what we're working with. Here's the potential
> angles of approach.
> /NOTE: No matter what we do, we need to add drives in pairs, for RAID 1+0, and
> we really would like at very least 2TB more space. Which requires at least 4TB
> of drives../
<snip lots of options>

The other possibility is that we move or remove the webcam archives. Don't 
we have lots of big fileserving hardware that isn't being used? Can we get 
some of that back in service?

Alternatively, I vaguely thought about running the whole archive through 
that flash new lossless JPEG algorithm[1] and then teaching the webserver 
how to decode it.

[1]: https://blogs.dropbox.com/tech/2016/07/lepton-image-compression-saving-22-losslessly-from-images-at-15mbs/

David Adam
zanchey@