Hot Swap Power Supply with only one Power Supply?

  • How can you have a hotswap PS with only one PS? Just curious........ as I don't see the value.


  • Because it's just one of the two needed.. perhaps you'll buy the second one later, or you already have one.

  • It's hot swap, you can safely pull it while it is running. Hot swap refers to the ability for a single component to be removed without needing to power down first to safely do so. That you don't have a second failover device to fail to when you've hot swapped the other is a separate matter.

    But hot swap only refers to the capabilities of a single device, it in no way implies failover or high availability technology.

    Same as how every RAID controller offers hot swap on RAID 0. It's useless, but it is there.

  • @scottalanmiller said in Hot Swap Power Supply with only one Power Supply?:

    Same as how every RAID controller offers hot swap on RAID 0. It's useless, but it is there.

    Love it.

  • In the case of RAID, it means you can pull a drive, replace it, and build a new array while things are still running. In the case of a cache location, it would actually be potentially useful, actually.

  • The point of this is simply easier maintenance if it actually fails.

    The server is still down. You are SoL there. But you can simply pull and swap the power supply once you get it delivered.

    It is typically very easy to slide out a powersupply in most any rack and put in the new one.

  • @JasGot just think of it in as "tool-less replacement" if you only have the 1 unit and no redundant unit installed.

  • Besides what has been said, option 1 is the lowest cost but also requires the most amount of work to swap and perhaps most important - needs a technician that can do it.

    Option 2 is a little more expensive as the power supply is more expensive but basically anyone can swap it. The amount of skill required is low and it only takes a few seconds. If you have a spare on the shelf for a few servers , you can get up and running pretty fast for a low additional cost.

    Option 3, well this is the redundant option and in general the one to get if you have your gear in a datacenter. While the power supply themselves are redundant and the server can survive a power supply failure, perhaps more important is that it can be fed with power from two sources. If a circuit breaker, an UPS or something else fails in the datacenter, only one power supply will have power but the server can still run. Datacenters usually have redundant power to the racks and to take advantage of that you need redundant power supplies.

    In general I would avoid option 1 for a rack server (unless you have Dell/HP doing the swap and all equipment is in warranty). If budget is an issue go for option 2.

  • It's the capability of the device to be hot-swappable. Purchasing one then adding another for some other time for a proper set-up is possible.

Log in to reply