Every rack unit costs money each month to keep running, whether a working system sits in it or it stands empty
About 15 minutes, with one month of bills
A rack unit is one slot in a rack. Space, power and cooling arrive on separate bills, so no bill shows what one slot costs. Add three lines, divide, and write the answer next to the date.
- Yes 2
- Written down, with a date (a log, a screen, a document), and it meets your own plan.
- Partly 1
- Remembered, but not written down, or the record shows you missed your plan.
- No 0
- Nobody knows, or it was never done. A blank is a finding.
"None, checked on a date" counts as a record. No plan or target written down? Write your guess first, then measure: the guess is your plan.
Tap No, Partly or Yes for each question. Your score adds up as you go. Nothing you tap is saved or sent.
Five questions about your own setup
1 Space
Your answer, and where it is written down (with the date) What does the rack's floor space cost a month?
Score 0, 1 or 2This quarterNext quarterHow to raise it
- Where to find it:
- Your lease, or the colocation bill (the bill from the data center you rent space in), for one month.
- To get it to a 2:
- A monthly figure read off the lease or bill, with the date.
2 Power
Your answer, and where it is written down (with the date) What does the rack's power cost a month, at the rate on your power bill?
Score 0, 1 or 2This quarterNext quarterHow to raise it
- Where to find it:
- Ask facilities for what the rack draws, then take the rate from your power bill.
- To get it to a 2:
- The draw from facilities and the rate from a bill, multiplied, with the date.
- What this does not prove:
- Power draw differs by system, so a whole-rack figure is not the cost of any one system.
3 Cooling
Your answer, and where it is written down (with the date) What does cooling that power cost a month?
Score 0, 1 or 2This quarterNext quarterHow to raise it
- Where to find it:
- Ask facilities for the cost of cooling the rack's power.
- To get it to a 2:
- A figure from facilities, written down with the date.
4 One rack unit
Your answer, and where it is written down (with the date) What do the three add up to, divided by the number of rack units in the rack, and is the answer written down with the date?
Score 0, 1 or 2This quarterNext quarterHow to raise it
- Where to find it:
- Rows 1 to 3 added, and the rack's height in rack units, counted at the rack or from a diagram you have checked against it.
- To get it to a 2:
- The sum and the division written down with the date.
- What this does not prove:
- An even split is an average, not what one system costs.
5 The last time it was worked out
Your answer, and where it is written down (with the date) When did someone last work this out from a real month of bills?
Score 0, 1 or 2This quarterNext quarterHow to raise it
- Where to find it:
- Your notes, or pull one month of bills now.
- To get it to a 2:
- A dated read inside the interval your team sets. No interval written down? Write your guess and score against it.
Your total, out of 10
- 9-10 Known
- Score the same page again next quarter.
- 5-8 Partly known
- Fix your lowest row this week.
- 0-4 Assumed
- Do row 1 this week.
Two rules beat the total: if row 1 scores below 2, the result is Assumed. Any row that missed your plan or guess is your next step.
Is your rack's monthly cost a number you could find from a bill, or a question for facilities?
What this does not prove
A cost per rack unit is an average. It does not show what any one system costs, or what an empty unit would save.
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