[nSLUG] Multiply-claimed blocks?
nslug at fop.ns.ca
Wed Aug 31 14:26:35 ADT 2011
On Wed, 31 Aug 2011, Daniel Morrison wrote:
> On 31 August 2011 14:12, Dop Ganger <nslug at fop.ns.ca> wrote:
>> I also vaguely recall hearing about a prof who ran a daily md5 of all
>> the files in his ~, and regularly found checksum errors.
> Sounds to me like that prof had a bad hard drive (or maybe his
> computer was at a high altitude?)
This was a shared computer. He did it because everyone else believe the
system was perfect as long as there was no error, and he believed there
wree intermittent errors coming through. I think he was seeing an error
every month or so.
> At my old job, for many years, all system files on some dozens of
> machines were checksummed nightly, and any discrepancy had to be
> explained. There were no (or so few as to be negligible) occurrences
> of spontaneous changes.
Few != none.
I suspect this is a problem that won't be seen in a system that's
protected by ECC or similar all the way through, but the system I'm
talking about was a shared system for departmental use - I think an
Ultrasparc of some description.
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