On 10/7/19 10:20 am, Reindl Harald wrote:
Am 10.07.19 um 01:22 schrieb Adam Goryachev
I'm not sure why I disagree with you Wol... why is RAID10 so much better
than a 3 disk RAID1?
because rebuilds are much faster and a RAID with 3 disks is a joke anyways
Ummm, so a rebuild of a RAID10 with 3 disks is faster than a rebuild of
a RAID1 with 3 disks?
The replacement drive will write at 100% of it's speed (as long as we
can read from the remaining two disks at least at that speed).
So, the difference is can we read from one of the two remaining disks at
the maximum write speed of the third disk in RAID1 x 3? I think the
answer would be yes, and therefore the real world difference in rebuild
speed would be negligible (if not zero).
Why is a RAID1 with 3 mirrors a joke? It has better data protection from
disk loss than RAID10 (with standard 2 disk mirrors), RAID5, or RAID6
(which is excluded here anyway as you need a minimum 4 disks for RAID6).
Actually, I really am curious, because if I'm missing something, I'd
like to improve my knowledge and make better decisions in the future.
PS, unless you were referring to 3 disk RAID10 as a joke?
TBH, I really don't understand RAID10, other than improving performance.
For example, in a 10 drive RAID10, you have a higher probability to lose
2 drives that are a "pair" than losing 3 drives in total from a 7 drive
RAID6 (both events lead to total data loss, although potentially you
could recover more "usable" data from the RAID10 array since you would
more likely have a large amount of contiguous data).
Regards,
Adam
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Adam Goryachev Website Managers www.websitemanagers.com.au
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