Request for feedback plans for building a new server room/closet

Posted by Maxolon@reddit | sysadmin | View on Reddit | 12 comments

This is in outback Australia. The small company I work for has hired so many people the server rack is being evicted from the office it lives in. The plan is to build a room inside an attached shed which will house the servers, some switches, my dev machines (retired desktops on shelves), AC, and possibly become the handoff point when fibre arrives. The company has 15 staff on site, and 7mb uploads mean most things are hosted locally. The word "shed" probably makes people nervous, but it's 7mx7mx5m tall on concrete and is used for storing supplies with CCTV inside and out, and security alarms. The build plan for the server room is full insulated walls, drywall interior, and properly sealed doors (with locked doors that they don't get keys to, outside of an emergency). Internal dimensions are 2.1m x 1.4m x 2.3m. There will be two 820mm wide doors, one directly in front of the rack, and another on the side wall at the rear. This should allow me to open the front door for extra access if needed. There will be 600mm clearance behind the rack plus the side access door, and 1.1m in front plus being able to open the door Split system AC will be installed and so far a 500mm minimum separation from the rack seems normal. Hot/cold flow will be tricky to impossible to implement in this space. I'm thinking of an APC 44U 4 post rack with overhead cable tray from the wall, vertical cable management and a fibre and Cat6a patch panel. I'm getting 2 X 15 amp circuits wired, and thinking of a 10 amp circuit as well. The current rack lives quite happily on one 10 amp circuit, but I want expansion room because I won't get another shot at doing this. There is an APC 1500va UPS for the two servers in the rack. The rack will be grounded via earth cable as well. Data links will mostly be handled by 2 SM fibre pairs run to each of the existing switches in the building. Long story short, centralised cable routing is not an option due to past building design choices. One pair will be used for a LAG to each switch, the other will be spare. I need to get an SPF switch with two SPF+ ports for the new file server, or possibly an all SPF+ switch, but I feel like that is a separate post. I'd like to add environmental monitoring for the room for server shutdowns. What have I missed?

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12 Comments

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Sir-Vantes@reddit

The Cooling rule is that for every kilowatt consumed, your cooling capacity needs to match or exceed. Early days was a Lab Rat for a major software vendor and that was absolute. If a building lost cooling, it was shut down, no matter how many machines would go dark. Your weather service might have a chart of heating/cooling degrees required each year plus a few more details. Size your systems to that, plus your OMG factor, for an effective cooling capacity.

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pdp10@reddit

* Get a firm budget commitment while leadership is still hot to make this happen. You don't want to be in a situation where you're only half built-out, but the immediate business emergency has been solved, and all commitment dries up magically. * Two separate mini-splits. If there's only one CRAC and it fails for any reason, you're on a countdown timer before everything has to be shut down due to ambient temperatures. * Moving the uplink demarc will tend to be painful and effort-intensive. * Needing two separate links to the existing facility isn't all that bad, as it gives you some redundancy. * Multimode fiber should work fine, but in recent years, singlemode has proven more future-proof.

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Maxolon@reddit (OP)

>* Get a firm budget commitment while leadership is still hot to make this happen. You don't want to be in a situation where you're only half built-out, but the immediate business emergency has been solved, and all commitment dries up magically. I'm confident that the build will be funded as needed. If it's not the business stops as no server=no money. >* Two separate mini-splits. If there's only one CRAC and it fails for any reason, you're on a countdown timer before everything has to be shut down due to ambient temperatures. The most likely failure would be from power outage, in which case environmental monitoring will sleep everything anyway. If the AC breaks we can get it fixed, the AC contractor works mainly for us as a in contractor. >* Moving the uplink demarc will tend to be painful and effort-intensive. Current WAN link is VDSL over copper. Any upgrade will require pulling fibre to the building somewhere anyway. If they won't pull fibre to the central rack then we can run out own fibre from the ONT to the server room. The only other time we would move the uplink is of we relocated. >* Needing two separate links to the existing facility isn't all that bad, as it gives you some redundancy. Agreed >* Multimode fiber should work fine, but in recent years, singlemode has proven more future-proof. Agreed. I'm going SM fibre with LC connectors so that it's standardised everywhere and reduces headaches, plus existing fibre is already to that spec

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jknvk@reddit

> Split system AC will be installed and so far a 500mm minimum separation from the rack seems normal. We’re talking a full-sized central split, not a mini-split AC, correct? A mini-split is fine for humans, but it may easily get overwhelmed by the amount of heat generated by your gear.

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llDemonll@reddit

We have plenty of small rooms running on mini splits. Sized appropriately they’re no different than central AC.

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pdp10@reddit

Redundant Array of Inexpensive Mini-splits.

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Worth_Jackfruit_4568@reddit

Have you considered rack cooling instead of or in addition to room cooling? I'm not sure if that would be financially feasible, but redundancy in cooking can help in a hot climate.

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Maxolon@reddit (OP)

I looked at one in rack cooling unit. It costs $4k, wall mount is $2.5k and more powerful, plus in rack doesn't seem suited to 4 post racks.

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Cooleb09@reddit

> What have I missed? Give a mob like kounis a ring, they do this shit a lot.

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Sudsguts@reddit

Onya for staying on-premise. Use up that 15a circuit with an Eaton or Socomec 6 kw UPS with Netvision card for network power down & monitoring. Power the whole room (not the aircon). A 10kw genset (you could keep the shed aircon running too). Because they'll howl at you to keep it running as long as you can.

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Maxolon@reddit (OP)

The current UPS runs the rack for >25 mins, which covers most of our outages. There's no appetite for a generator as if the power is out people will just go home and start sorting their houses out. Nothing else in the office is on battery backup, including the modem, so I'm not too fussed about that.

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Sudsguts@reddit

Sweet.