Re: raid10 or raid1+0 ?

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Hello all,

thanks for your responses.

Quoting Bill Davidsen <davidsen@xxxxxxx>:

Neil Brown wrote:
On Monday August 27, jpiszcz@xxxxxxxxxxxxxxx wrote:

I have a few people who asked me this as well, RAID10 or similiar (SW). I am not so sure, with RAID1 you can have your root disks on it and boot from it using LILO/GRUB and it is proven pretty stable; can the same be said about RAID10?


For your boot partition, use raid1 - not raid10.

For others, you get to choose.
The md/raid10 module was created to make is easier to manage a
combination of striping and mirroring, and to provide extra
functionality such as handling an odd number of drives, and 'far' or
'offset' modes which provide raid0-like read performance.


And this is the first (of two) reasons to use RAID-10, it's fast. Even
with a boatload of read ahead, RAID-1 will give you peak read speed of
about that of a single drive. RAID-10 will run at multiples of that.

Okay, you mean the difference between RAID-1 and RAID-10. But the difference between RAID-(1+0) combination and RAID-10 (in "near" mode) should be marginal ?!

So, when looking at the raid r/w performance, is the following table correct ?

+-------------+------------+-------------+
| raid type   | read perf. | write perf. |
+-------------+------------+-------------+
+ none/1 HDD  |     =      +      =      +
+-------------+------------+-------------+
+   raid 1    |     =      +      =      +
+-------------+------------+-------------+
+   raid 1+0  |     +      +      +      +
+-------------+------------+-------------+
+ raid10(near)|     +      +      +      +
+-------------+------------+-------------+
+ raid10(far) |     ++     +      -      +
+-------------+------------+-------------+

Best regards
   Thimo Eichstaedt

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