Any server admins about?

maverickTue 04/03/08 11:04

Morning guys,

The past few days our server has been particularly slow due to a DDOS attack. We're working on resolving this at the moment.

We manage our own server. The provider said that we're 'swapping' when we shouldn't be. They're very vague and not at all helpful. I have no idea what swapping means or how I can change this.

Can we alter this using cpanel? If so, how do we go about it?

Cheers for any help.

Paul

keithyTue 04/03/08 11:08

swapping usually means swapping memory to disk.
It woudl mean you do not have enough physical RAM for what the computer is trying to do.

keithyTue 04/03/08 11:11

More explanation - computers have a certain amount of memory, "RAM", which is fast and efficient and is where running programs are located, along with any data they use etc (this is a generalisation, but it gets the idea across).

When you try to load more into memory than you have RAM, the computer will move some of the stuff it isn't immediately using onto swap space, a special area of disk. This frees up some memory for the rest of the stuff, but takes time.
When it needs that information again, it moves something else to disk and loads up the bit is stored.

So this way it can still work, it's just slower.

An analogy - you might remember a few figures for something, but if you need to remember something else you might jot those figures down on a notepad then refer back to the pad when you need the figures again.

Swapping really slows things down if it happens a lot, which woudl be the case if you are trying to do far more than your computer memory allows.

Solution is usually either add more RAM, or reduce the things your computer is doing.

hope that helps?

maverickTue 04/03/08 11:14

Hey Keith,

Thanks. Any idea how we turn swapping off?

We have 4gb RAM which should be sufficient but because of the DDOS attack, most of the resources are being hammered.

What an absolute pain in the arse and waste of time.

maverickTue 04/03/08 11:17

Just read your updated response. Thanks for the explanation.

Perhaps we do need more ram. Or perhaps we just need to sort the firewall out to block attacks :D

keithyTue 04/03/08 11:17

If you turn swapping off, then your computer will pretty much stop working when it runs out of memory :-(

I'm assuming it is a Windows server? You can disable VM (Virtual Memory is what it's called technically), but Windows will strongly advise against, and as I say it will probably result in teh machine stopping working - if you do turn it off then remember to turn it on again when all's well again!

Hope they manage to block the DDOS soon for you - scumbags like that really don't deserve to be allowed anywhere near technology :-(

keithyTue 04/03/08 11:19

Blocking the attacks woudl be the ideal way to handle it :-)
Although that said, it is pretty much true than you can never have too much RAM in a computer, especially a server ;-)
However, be aware that if you do add more RAM at the moment, the DDOS will still most likely cause the system to swap.

Blocking the attack is the best way to go.

maverickTue 04/03/08 11:27

Cheers Keith,

The OS of the server is Linux - Red hat.

So it seems swapping isn't such a bad thing and we don't need to turn it off.

We're just installing some modules, that will auto add the IP address of the offending IP's to the hardware firewall.

We're pretty sure it's a competitor, it's been going on for a few days. I hate dirty tactics by competitors. It's amazing what's allowed to go on, in the online world. Imagine going in to a competitors store and trashing the shop. Grrr

Thanks again for your help.

maverickTue 04/03/08 14:27

Holy, fucking, shit, batman.

We asked our host. Softlayer to install 4 modules. $3 per module, no problem.

We received an email informing us that the modules were installed. At which point, all of our sites had internal server errors.

It took them 2 hours to resolve the issue, well they said it was resolved but our main website had some strange redirect put on it, and redirected to the WAP site.

We asked them what on earth they had done and to please fix it asap. They responded saying as it's an admin task, we'll be charged a further $3 for them to fix the issue.

I wondered if I had dozed off for a minute, it's not the $3 but the absolute audacity.

I am not a happy bunny right now.