Power supply means bigger capex and less redundancy, as the emergency procedure in case of power failure is less deterministic than with controlled battery-backed cache. Cache battery is smaller and way more predictable for a health measurements than a UPS (if passes internal check, it will be *always* enough to keep memory powered for a while, but UPS requires periodical battle testing, if you want to know that it still be able to hold power failure, with two power lanes should be safe enough, simply because device itself has more complex structure than a battery with a single voltage stabilizer). Anyway XFS nobarrier does not bring enough performance boost to be enabled by my experience. _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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