Hi, can somebody tell me what a 1U, 2U, 20U, etc. colocation means?

@Holocryptic ...

1u refers to how tall the server is in the rack. Colocation refers to a site that is outside your main premises connected via VPN or some other method; usually as a DR site

how many servers can a 1u colo hold?

yes, basically most pro computer kit fits into 19 inch wide racks, they're the standard, and they're classed by their height, 1U is ~4.5cm, 2U is twice that, 9cm etc.

no, I think you're misunderstanding

oh! sorry

well it'd be whatever you can get into 4.5cm - which is quick short

got it. Thanks a lot.

there are lots of servers and small switches that DO fit into 1U; HP/Dell/IBM etc all make 1U servers but usually they're a little limited in their expansion - whereas the best selling servers tend to be 2U high as you can get more into them

lots of disk shelves are 2 or 3U and support say 12 or 14 large 3.5 inch disks or 25 2.5 inch disks

there are bigger multi-CPU servers that can be as large as 10U (95cm) but they're rare

what it is you're trying to achieve?

Nothing. I am new to this stuff.

Thanks for clarifying

Wikipedia, as always, has a good overview, but the U is a unit of measurement. A server may be 1 or 2U, while a UPS may be 3 or more.

yep. You can browse the main site and pick up on a lot of information

A 2U colocation would, I presume, would give you space for a 2U server (may or may not include UPS services, but I would hope it would), presumably a network port uplink and a power cable.

@tombull89 okay. But Wikipedia isn't very clear about the U's

U is just short for "unit"

It's weird because they work in inches, instead of cm, but still:

better

hmm...

Think of a "U" as being a standard amount of space on a rack that you rent. You can fill it with what you like - if "what you like" includes standard servers and other network services that fit into a standard rack.

@its_meα you can fit 1, 1u server in 1u

@Iain And since most servers today are 2U, I can think of it like this... 20U colo = 10 servers, right?

@RobMoir yeah, I understand now

@its_meα define servers

its not a case of "most servers" = 2U. There are all kinds of servers at all kinds of sizes.

2U servers are a good compromise between being small and having the space to expand as chopper says.

@its_meα typically, yeah, your average rackmount server is 1 or 2 U, although you get machines that can take 4U or more.

@Iain :( I meant to say, if a server in general sense is considered 2U (size) then 20U colo can hold 10 servers

1U servers are good for servers where you might want decent processor and RAM but not much disk space.

For example, the HP Proliant DL380 G7 is a 2U server, although if you add a storage array (also 2U) that takes your total up to 4U.

20U can hold 10 2U servers, yes.

You can get higher density if you look at blade servers but thats when it starts to get complicated

@RobMoir not to mention expensive...

@RobMoir for servers == hardware

I've generally found that for the same specs, a 2U will come in a tad bit cheaper than 1U

true enough @Iain, if you needed 10 servers you'd probably also want more infrastructure to support them. @tombull89 yes, expensive, but great for density

@RobMoir ok

reads up

I see lots of red hats in the room today, HAPPY HOLIDAYS by the way

happy christmas :-)

@its_meα & to you too

thank you :)

@tombull89 When we got blade servers several years ago, they came out cheaper than discrete servers...

I think the Unit measurement came from telephony - its the same as a single standard sized switch or something

Does it mean you are all out of work for a few months?

@JourneymanGeek - I reckon you're right. Telephony/comms

eh

I'm on vacation until the 3rd of January.

but i'm being paid for it ;-)

nice!

@freiheit Really? Probably not the case now.

It's a lot of up-front cost for the blade chassis, then the individual blades are a bit cheaper and somewhere around 1 blade shy of a full enclosure, it's full. Much more power efficient if you want redundant power... A pain if you don't get a lot of the exact same config, though

@itsme: Eh, no job anyway. On the bright side, i just added a new skill to what i know

@RobMoir same. 3rd Jan for me too.

Anyone around know of/use NOD32?

@JourneymanGeek and that is?

@Jacob we do.

@itsme: I can fix LCD monitors ;p

normally does a decent enough job.

@tombull89 I take it you use the remote admin console

@JourneymanGeek chuckle

well, with the most common issue they seem to have

@freheit - I guess it depends on how you value density / power consumption / etc. If a blade server saves you having to buy another rack, run 2 32 amp feeds to it, possibly upgrade your cooling....

@JourneymanGeek that's nice too, 'coz I can't

@Jacob yeah, although it's normally set and forget and it does it's own thing.

@Jacob used to run it at home but thats about it

@Jacob serverfault.com/questions/ask

@Iain Thanks Iain

@itsme: not hard. there's three common errors. two arn't worth fixing, but you can replace the whole circuit board. The third involves replacing cheap components ;p

@Jacob it's always a pleasure - You are a precious snowflake. This is *NOT a place for 'Live Support', ask questions on the main site.*

@JourneymanGeek lol!

back to planning and testing our windows 7 rollout next year

what fun!

Guys, I heard that Google still uses PCs for servers, so that they can get lots of processing power dirt cheap. Does anyone else do the same?

er

by PCs you mean commodity x86s? ;p

right

Google build their own servers...

i don't think google use "off the shelf" PCs for servers - I think they build servers out of "off the shelf" x86 parts.

oh...

Not uncommon in the education sector, or where you need an epic crapload of identical redudant systems

CERN runs a distributed cluster in several universities thats basically racks and racks of bog standard mini tower boxen

@RobMoir I mean, that a few years ago, comparing a blade chassis full of blades to the cost of the same count of 1U or 2U servers, the cost of the blades came in cheaper.... but it was edu/government/contract pricing from HP.

Would I use self-buit servers, in production? Not really, no. You can't beat phonng DELL or HP because a card's gone funny or a HDD's died and getting a new one less than 4 hours later.

their workload is designed to be massively distributed, so what they do is pretty damn clever but not a common case

@tombull89 For some reason, it doesn't want to deploy, instead it rather "wait(ing)"... Wanted to see if anyone else had an issue. OR I get Access is denied which is odd because I type my Domain admin account.

@freiheit no you're absolutely right... I'm just saying that sometimes there's more to the cost of deploying a box than the cost of the price sticker

ya. For personal use, it makes some sense. A good part of the fact that enterprice grade systems cost more is in service

@Jacob as I said it's set and forget, never really had any issues with it. Ask a question on the main site, or see if there's a ESET knowledgebase.

@RobMoir The big reason we're not getting more blades is if you're not buying a whole enclosure worth of hardware at once and don't need the same connectivity options for everything, it sucks. Plus, the kind of hardware we want for VMware hosts doesn't work out cheap as blades.

This is a very basic question. How do I learn more about computer & server hardware? join a course? is that the only best way?

we have a couple of PCs we use as test virtual servers running hyperV for dev use only. Its all good stuff

@freiheit absolutely agree. We use blades and I like them but they're certainly not a magic bullet answer to every server room problem.

I've got no qualms about running self-built stuff at home (indeed, my file server is self build, stock Core 2 Duo, Intel MB, 2GB Ram, 3x 2TB disks in Server 2008 Software RAID 5), never really have any issues.

lol

@itsme courses are good, but also its one of those things you learn by doing.

My personal server is a 1.6 ghz atom, 2 gb of ram, 250 gb hard disk.

@its_meα lcg.web.cern.ch/LCG

I know they're somewhat basic but I still like the A+ type courses for learning about basic PC hardware

hmm

@its_meα Try volunteering at a local school or college, get some work experience. In the UK we run apprenticeships, where you work at a placement for four days a week, and go to college one day. At the end, you've got a qualification and experience. That's what I did, the experience of me working in a school got me my first job.

@RobMoir My PC rarely has any problems!

@itsme: help out people then ;p

that's another good reason to buy your hardware from the likes of HP or Dell of course, they also run courses on fixing and supporting their servers at a hardware level

I've done courses as well but you can't beat experience.

go trawl superuser for stuff

@JourneymanGeek :) hmm...

@itsme - the A+ style course are a great grounding in the basics of x86 architecture based machines that can fill in any gaps in your knowledge before you do more advanced training

if you wanted to learn about hardware, I mean.

and experience is also important, that's the one thing you can't go on a course for, of course

@Rob, have you done any of the CISCO CCNA-syle courses? would you reccomend them at all?

@RobMoir okay...

@tombull89 not done them myself as we're not a Cisco shop but I know people who have who seem happy with them.

It's the holidays! Time for some spirit!

I've been toying with doing them for a while, but they're not cheap to pay for (£1200+ afaik) so I'm wondering if it's really needed.

i have several bottles of spirits!

@tombull89 I'm guessing your place won't do them as CPD?

@RobMoir No such luck.

@RobMoir: eh, mine had an equivilent course that yonked a lot of content off that... badly taught though

Indeed, my local college (where I've done IT courses before) offer the CCNA but it's still near a grand mark.

one of the colleges near mine does them but its a bit of a hike from Bristol to Luton

haha, just a bit. The money I save on the course I'd spend on fuel.

Another WordPress update? >_< sighface

@JourneymanGeek yeah it can be a bit ropey but I know the guy teaching the CCNA portion of the course at the place near me, its their it manager and he knows his stuff and has actually seen some of the front line shame instead of just a bunch of teachers theory

@RobMoir: also cause it was a module they don't regularly offer, and they got a part time guy to do it

ah not so good

I'll probably look at certs closer to my final year, or while i'm job-hunting ;p

@JourneymanGeek is that your puppy?