RAID array [LWN.net]

RAID array

Posted Mar 19, 2008 20:50 UTC (Wed) by wtarreau (subscriber, #51152)
In reply to: RAID array by clugstj
Parent article: On the vger.kernel.org outage

RAID is not about resistance to any sort of partial failure we can imagine,
it's about ensuring that upon a disk failure you will not lose your data.
If one disk becomes 99% slower but still works, there's no reason it would
be marked faulty, but in practise the service is not assured anymore.
However, having a guy overthere replace it fixes the problem.

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RAID array

Posted Mar 19, 2008 21:02 UTC (Wed) by ajross (subscriber, #4563) [Link]

That said, raid arrays that fail when plugging in a specific device are awfully suspect.
Signal problems on the port should be a soft failure, not a hard one.  That's the whole
spending lots of money on server hardware.  If it was OK for a drive to take down the system,
they could have been running on a $900 box from Walmart.  All file server boxes really need is
a ton of RAM.  Disk bandwidth needn't enter into it.  Didn't I see a report a while back that
kernel.org was, in fact, serving everything out of cache anyway?

All of which, really, just goes down as evidence for my long-held opinion that hardware-level
solutions for reliability never work.   Reliability can only be achieved at the software level
via full redundancy.

RAID array

Posted Mar 20, 2008 17:31 UTC (Thu) by dmarti (subscriber, #11625) [Link]

"Reliability can only be achieved at the software level." Instead of a mailing list, a Usenet-like discussion system on top of git?

RAID array

Posted Mar 21, 2008 6:20 UTC (Fri) by njs (guest, #40338) [Link]

Amusingly, the original vision for monotone actually had NNTP as the primary intended network
transport.