The operating system device for master nodes should be highly available. This usually means RAID-1 (a mirrored pair of disks). Since the OS does not consume a significant amount of space, RAID-10 or RAID-5 would be overkill and lead to unusable capacity. Most of the real work is done on the data devices, while the OS device usually only has to contend with logfiles in /var/log.
Small clusters—clusters with fewer than 20 worker nodes—do not require much for master nodes in terms of hardware. A solid baseline hardware profile for a cluster of this size is a dual quad-core 2.6 Ghz CPU, 24 GB ...
Master node configuration baselines.
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