Am 02.12.2017 um 14:14 schrieb Gandalf Corvotempesta:
Il 02/12/2017 00:44, Reindl Harald ha scritto:
a RAID10 can survive two faile disks while a RAID5 is for sure dead
Absolutely not.
This is a common misconception.
RAID-10 can survive two failed disks IF AND ONLY IF these disks are on
different mirrors.
i know that - thats the difference between "will" and "can"
I had multiple (more than 4) RAID-10s totally lost due to double failure
in the same mirror.
Each disk in a mirror will get the same write pattern, thus, you'll risk
a double failure for any
firmware bugs or similiar. With SSDs this risk is higher, because you
wear out both members
in the same way at the same time
when you are not an idiot the mirror is not the same disk or not the
same age, guess why i replaced first two of the HDD's with SSD's and
somewhere next year i plan to replace the remaining two too
and for 4 disk RAID10 with HDD's i use typicaly 4 different disks at all
from as many vendors as possible (the machine in the office is from a
time where you had 4 real vendors)
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