maximum number of physical disks in RAID 10

Please don't top-post. Corrected below.

wrote:
Of course he's wrong there too. Any write to a stripe where neither
the data block nor parity block is on the failed drive is unaffected
(and performs exactly as before), and if the parity block is on the
dead drive, writes will actually be faster. Only if the data block is
on the dead drive is it necessary to read all the other disks to do the
update of the parity block needed to complete the write.

powermt wrote:
In a normal RAID 5 set where the data and parity is split across the
drives we will encounter a slow performance .
The point about writing faster when the block is data n not parity no
this is not a normal feature of a RAID 5 .it has to do something called
as parity shedding in order to speed up the process but that is again
risky since your RAID 5 boils down to a mere RAID 0 with no data
protection .


We were discussing RAID arrays with a failed drive. For writes to
blocks where neiter the data block or the parity block for the stripe
or on the failed disk, the RAID-5 write performance is as usual, and,
of course, has the 2-read+2-write overhead it always does. The other
two cases I described apply to operations where the dead drive *is*
nominally involved.

Disabling parity of a RAID array is something else entirely.