<s>
For	O
computer	B-General_Concept
memory	I-General_Concept
,	O
Memory	B-Error_Name
ProteXion	I-Error_Name
,	O
found	O
in	O
IBM	O
xSeries	O
servers	O
,	O
is	O
a	O
form	O
of	O
"	O
redundant	O
bit	O
steering	O
"	O
.	O
</s>
<s>
This	O
technology	O
uses	O
redundant	O
bits	O
in	O
a	O
data	B-Protocol
packet	I-Protocol
to	O
recover	O
from	O
a	O
DIMM	O
failure	O
.	O
</s>
<s>
Memory	B-Error_Name
ProteXion	I-Error_Name
is	O
different	O
from	O
normal	O
ECC	O
error	B-Error_Name
correction	I-Error_Name
in	O
that	O
it	O
uses	O
only	O
6	O
bits	O
for	O
ECC	O
,	O
leaving	O
2	O
bits	O
behind	O
.	O
</s>
<s>
These	O
2	O
bits	O
can	O
be	O
used	O
to	O
re-route	O
data	O
from	O
failed	O
memory	O
,	O
much	O
like	O
hot	B-General_Concept
spare	I-General_Concept
on	O
a	O
RAID	B-Architecture
.	O
</s>
<s>
Memory	B-Error_Name
ProteXion	I-Error_Name
,	O
also	O
known	O
as	O
“	O
redundant	O
bit	O
steering	O
”	O
,	O
is	O
the	O
technology	O
behind	O
using	O
redundant	O
bits	O
in	O
a	O
data	B-Protocol
packet	I-Protocol
to	O
provide	O
backup	O
in	O
the	O
event	O
of	O
a	O
DIMM	O
failure	O
.	O
</s>
<s>
One	O
failure	O
does	O
not	O
cause	O
a	O
predictive	B-Device
failure	I-Device
analysis	I-Device
to	O
be	O
issued	O
on	O
the	O
DIMM	O
,	O
but	O
2	O
failures	O
and	O
more	O
will	O
issue	O
a	O
PFA	O
to	O
inform	O
the	O
system	O
administrator	O
that	O
a	O
replacement	O
is	O
needed	O
.	O
</s>
