Acer Altos easyStore M2 User Manual page 285

11 Install the HDDs, do so one at a time, then click Scan after each
action.
Note: It is strongly recommended that you install all the HDDs that
you want to use in the storage system at this time, since changing
the number of HDDs later can require disk reconfiguration and
possible data loss.
12 Click Next to accept the default disk configuration (which will
provide the best level of data protection available for the number
of HDDs currently installed).
By default, a linear disk configuration is used for a single HDD,
RAID 1 is used for two HDDs, and RAID 5 is used for three or four
HDDs.
If you want to change the disk configuration, select the desired
RAID level, then click Next. For detailed information about the
different RAID levels, refer to "Disk configurations" on page 232.
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