General discussion


Acceptable downtime percentage

By campbellwj ·
Hi all,

I was wondering if someone could point me in the right direction to find some information about uptime and downtime percentages. I would like to know what the acceptable industry standard is for uptime / downtime annual percentage. I did some numbers and found out that my MIS Department had a 98.9% uptime rating for 2001. I would like to have some input on this please.

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Number of factors

by James R Linn In reply to Acceptable downtime perce ...

Is your organization a 24hr organization? - if so then your stats should be based on 24 hours(and scheduled downtime counts as an outage).

If your org is not a 24x7 org, you should think about scheduling outages outside your working hours, and counting either only your working hours(and expecting amazing availability) or somehow weighting your working hours more heavily than your non-working hours.

You should also consider server classes. We have servers in our datacentre which are mission critical, and we care a lot more about their availability than the 5 year old workstation that someone uses as an occasional file server. We stratify our servers into levels and weigh the mission critical(email, financials, HR) far higher than the others.

We strive for 3 9s or 99.9 for mission critical servers in working hours. We usually meet or come close.

So you see its highly variable based on how you decide to measure it and why.


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Yes, percentages are funny things...

by bklein In reply to Number of factors

If your shop is 24/7 and your uptime is 99.0%, this means you're dead for 14 1/2 minutes every day.

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Right on.

by admin In reply to Number of factors

With workstations our business considers repairs not to be downtime if the maintanance/repair occurs during a time the WS is not needed or a loaner is used to replace it. Makes 99.9% uptime much easier. Of course, it's really scheduled downtime to us.

Good points on different ways to measure it. Internally we watch downtime differently so we can say "This machine needs replaced" but the company directors want bragging rights so that they can say "99.9%" uptime to the staff as a benefit. The trick is not to let it impact our budget..... "What do you mean we need to buy a new server? It has 99.9% uptime- why would we replace it....." That's when we need a whole different measurement :)

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Server replacement

by generalist In reply to Right on.

The part about 'not needing' a new server because of 99.9% uptime is SO true it is a problem. Maybe the thing to do is to prove that the 99.9% uptime claim is due to the server replacement policies. If they want to maintain that, they had better replace it.

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SIX SIGMA and Beyond!!!!

by e-Fellow In reply to Acceptable downtime perce ...

Six Sigma ratings are 99.9997%. So shoot for zero downtime and I am sure you do, however, 98.9% is 3.8 sigma IF YOU HAVE THE OPPURTUNITY TO BE UP 100% OF A 24 HOUR DAY AND YOU ARE UP 89.8%, then go to work. We have experienced about 3 hours of non-scheduled downtime in about 9 months and have only scheduled about 3 hours during operational hours. You have a problem somewhere, find it, fix it or live with it.

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Not that simple

by James R Linn In reply to SIX SIGMA and Beyond!!!!

If we could keep the same suite of applications running for 1 year, with no downtime for upgrades, service packs, memory upgrades, disk upgrades, processor upgrades etc., that would be a realistic goal.

We have a scheduled downtime once a week, so we strive to make sure we do as little as possible outside the scheduled downtime.


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by e-Fellow In reply to Not that simple

Think outside your box and listen to what you said to me, "We have a scheduled downtime once a week". Why do that, if you have a good reason to do that, find a way to stop, good grief. CSM, common sense management. Run the system do not let it run you. There is no such thing as a realistic goal, why set an unrealistic one,,,,,,,, there is a 99.999999% you are not going to invent the technology to make your situation better, so find out if you are the best, if not, mock the best. Good luck guy.

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Common sense

by James R Linn In reply to THE "I CAN'TS BECOME I CA ...

is something I follow every day.

First of all, we don't have a bad sitaution. We often have 99.95% availability, and if you looked at our normal working hours, we'd probably be close to the 99.999% goal.

We have a 3 hour maintenance window, outside of normal working hours. We only take down servers which require maintenance - and sometimes routine maintenance waits for an opportunistic time.

For example we like to keep our servers on the same Service Pack, but its not absolutely necessary for all servers from a technical pespective. So instead of taking it down at the first opportunity, we wait until the server needs a reboot anyway.

All I am saying is be realistic. Not all businesses need electronic services 24/7. Some scheduled maintenance may sacrifice short term availability, but improve long term performance and reliability.

You don't have to wish me luck thanks. I'm doing just fine thanks very much.


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by e-Fellow In reply to Common sense

You said that your uptime was 89.9%. If your users are not able to access critical systems 10.1% of the year then you are right, you need a lot more than luck.

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Read again

by James R Linn In reply to BAD LUCK THEN

I never said 89.9. I said 99.9 is our goal (measured 24x7) and we usually meet it. And as you will see our customers are not expecting our services to be available more than 8-6 Mon-Fri, because that is when they work. If you took that period of time, we'd be closer to 99.999.

Please get your facts straight before you insult others.


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