Panasonic WJ-NV300K Operating Instructions Manual page 74

Note:
• When one of the HDDs is replaced in the mirroring
mode, "Add" will be displayed in the status infor-
mation section of "HDD information". The newly
replaced HDD will start working in the mirroring
mode when "Add HDD" is executed. In this case,
all data on the replaced HDD will be erased.
• It is not possible to change the mode directly from
"Mirroring mode" to "RAID5 mode" or "RAID6
mode" (and vice versa). When changing the mode,
make sure to change it to "Single mode" once,
then change it to the desired one.
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