[sclug] Debian Squeeze boot up messages: moving on.

[Alex Butcher]

On Fri, 22 Feb 2013, Neil Haughton wrote:

> Okay, I've rescued my data from the dodgy disk onto another disk, so I'm
> going to bite the bullter and install a SSD for OS/apps and a twin mirrored
> RAID for my data. That's my summer holiday up in smoke and I'll have to buy
> Her a new frock, but ce la vie. :-)
>
> I'm stepping out of my comfort zone now, but here are the challenges and
> potential pitfalls as I see them:
>
> 1. I only have PCI slots and IDE sockets (no PCI-E or SATA) on my
> ancient-yet-stalwart motherboard. Reasonably Priced Disks these days tend
> to be SATAII or better, and for a PCI slot it seems I can only get SATA
> adapters, not SATAII.

WD still make PATA drives, but they max out at 500GB:
<http://www.wdc.com/en/products/products.aspx?id=770#tab3>
<http://skinflint.co.uk/western_digital_caviar_blue_500gb_wd5000aakb_a241323.html>
<http://skinflint.co.uk/western_digital_caviar_blue_320gb_wd3200aajb_a133552.html>

Though they're only Caviar Blue models, so only have a 2 year warranty:
<http://support.wdc.com/warranty/policy.asp>.  Black and RE models have 5
years.

> 2. I already have a relatively new 320Gb SATA drive in a caddy that I
> currently used through USB for my data. I would like this to be one half of
> the mirrored RAID, for obvious reasons.
>
> Questions:
>
> (a) So if I acquire a PCI/SATA adapter with three or more SATA sockets, and
> plug a new SATAII drive plus my 'old' SATA drive into it, using software
> RAID to manage them, can I expect any obvious problems? (I'm using Debian
> Squeeze, remember.) I understand that unless I am lucky enough to find a
> similarly sized drive, I will lose capacity on the larger of the two (ie
> the new one), but that doesn't particularly bother me.

Doesn't sound unreasonable, but you might need to play around with boot
order in the BIOS. Also, speaking of BIOS, if you need to update it, you'll
probably need to update it with the PCI card removed (the PCI card will
probably have a read-only option ROM which will prevent flashing of the
motherboard BIOS it partially overlays). I wouldn't expect Debian-specific
problems, but I'm not a Debian-specialist.

> I guess this boils down to mixing SATA and SATAII drives in a RAID (I
> accept that the SATAII drive will probably fall back to SATA, but that's
> streets ahead of my current mostly IDE setup so I'm happy with that), and
> similarly using a SATAII SSD in a SATA socket.

The difference between SATA and SATAII is 1.5Gbps vs 3.0Gbps data rate.
Drives are supposed to be backwards compatible. This may only be a
limitation in practice on the performance of the SSD (depending on how fast
it is, or isn't).

> Any data I wish to retrieve from my old IDE disks I will copy across to the
> new devices, in the time honoured fashion before I physically remove them.
>
> (b) If I acquire a 128MB SATAII SSD and plug that into the adapter, can I
> expect any problems? I intend to install a fresh Debian Squeeze onto it,
> and have everything except /var and /home there (/home will be on the RAID,
> /var will probably be on a single IDE drive that I will retain, or maybe on
> the RAID too, to save a bit of juice).
>
> Folks, waddaya think? Am I looking for trouble?
>
> Lastly, on the matter of SATA adapters, does price count? They seem to
> range from under ?10 to ?50 for what looks more or less like the same
> thing. Are there any such offerings that you folks know I must avoid, eg
> only work with Windows?

There are lots of buggy SATA controllers out there that corrupt data. From
my (probably incomplete list):

http://codemonkey.org.uk/2009/01/20/sata-disasters-silicon-image-3114/ # SiL 3114 bugged, corrupts data

http://marc.info/?t=123089876500001&r=1&w=2 # SiL 3114 bug thread

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/263160 # Sil3512 and VT6421 bugged

Unfortunately, those are all very common chipsets for PCI SATA controllers
and probably cover 90%+ of the market, and nearer 100% at the cheaper end. 
:-(

I think I eventually decided the only way to get a non-buggy PCI SATA
controller was to buy a Promise, Adaptec, LSI SATA RAID card of some
description.  That was so expensive, I went for a new motherboard with
(non-buggy) Intel SATA controller built-in and added a cheap Promise PATA
RAID card to access my legacy drives.

> TIA
> Neil.

HTH,
Alex