Re: USB storage no-boot regression (bisected)

[Mark Lord <lkml@rtr.ca>]

Arjan van de Ven wrote:
> On Thu, 16 Apr 2009 11:51:53 +0100
> Alan Cox <alan@lxorguk.ukuu.org.uk> wrote:
> 
>>>> Though it's an onboard USB SSD, not a pluggable stick.
>>> Wow, that's insane.  Leave it to a hardware designer to use a bus
>>> that you never know if you have discovered all the devices to be
>>> the primary device to boot from.
>> Let me see:
>>
>> - Standardised small component
>> - Low pin count and low wire count bus
>> - Cheap
>>
>> In an embedded environment where you know the device is wired in at
>> software level that strikes me not as insane but very sensible.
> 
> I'm not surprised usb is used for storage. What I am surprised at is
> that USB is used in such high end environments that rootwait is not
> sufficient and that the panic-rebooter is needed for the reliability.
..

Failover and redundancy are standard requirements for really reliable systems.
As good as a component may be, there's always anticipation that it will fail
someday, and multiple ways of detecting/overcoming failures must be built-in.

In this case, imagine *two* such SSDs.