Sampson's questions

I manage a small VPS and have noticed in the last few days that email usage has blown way out of the norm. What usually is only a few dozen has instantly shot up to our relay-limit of 1,000/day. The OS is CentOS and I'm running Simple Control Panel to assist me in setting up email addresses and domains.

How can I determine which account, on which domain, is sending/receiving all of these emails?

Resolving the issue:

As suggested in the accepted answer below, I ran the mailq command and was immediately flooded with a seemingly never-ending list of email addresses. Finally forcing the load to abort with CTRL+Z, I was able to discern which account all of the email addresses were coming from:

004F1C3D5B0* 22534 Fri Feb 11 12:27:48 [email protected]
    [email protected]
    [email protected]
    [email protected]
    [email protected]
    ...

This is an extremely small sample of what filled my screen. From this, I was able to determine that the lowercase email on the first line must be the address sending/receiving all of these emails.

I hope I'm not mistaken.

I tried to gzip a directory with the following command:

gzip -r /home/path/to/backups/mydirectory.gz /home/site/public_html/

I was expecting to see a .gz file show up inside ...backups containing all the files found in ...public_html. This isn't what happened. Instead, every file was (recursively) renamed to [filename].gz within public_html. This, obviously, brought an entire site down.

Two questions: 1) What did I do wrong with the syntax? and 2) How can I revert all of the filenames back to what they were before (exactly what they are now, minus the .gz extension).

I've got a server that receives around a million unique visitors a month and I've recently began using Plesk to help monitor some of the vitals on the box itself. RAM I can make sense of, but I'm not really sure if my CPU usage is too high, low, or about average for this number of visitors. The server exists solely to serve up a somewhat hefty WordPress blog.

This is one week. What types of things should I look out for? Some other information about this server follows:

VCPU(s): 4, RAM: 6GB, HDD: 30GB, OS: Ubuntu Server 10.04 x86_64

I'm using a new virtual server through GoDaddy, and this morning I received a call from the powers that be informing me our website was offline. After confirming this, I requested a power cycle through our GoDaddy control panel, and within a minute or two the server was back online. I made the call, and reported the news that we're back up.

Of course, a couple minutes later we're down again. I tried connecting through PuTTy, and it takes forever to prompt me for a username, and each successive prompt takes a long time to come up. I'm using CentOS. So my questions are:

1. How can I determine the cause?
2. What types of things can I do to prevent this in the future?

One interesting, and perhaps relevant, observation is that yesterday our bandwidth consumption was about 20% greater than our top figures from the past month.

New sysadmin here, managing a CentOS server. This past week has been one of the most exciting weeks of my career, and full of learning all sorts of new things. Today I have another task though, and that is to make sure our server can handle more than what our old shared-hosting was capable of.

We were originally limited to 200 concurrent connections on our GoDaddy shared-hosting. Eventually we out-grew this (usually during campaigns/marketing events) and moved on to a Virtual Dedicated Server. I'm assuming the number of connections would be handled by Apache.

What configurations should I be mindful of in order to allow more traffic in?

I've got a domain name that is managed through 000Domains.com. I also have a virtual dedicated server hosted with GoDaddy.com. Within my VDS, I created a folder /mysite and placed all of my website files there. I can test this through the ipaddress of my VDS, but I would now like to point my domain from 000Domains over to my sub-directory hosted on GoDaddy. How do I do this? Do I need to make any specific modifications to my VDS to inform it that one of the directories will be accessible from a domain name?

I have access to Simple Control Panel, if that is of any relevance.

Update

I've used the [domains] portion of my Simple Control Panel to add my domain (mysite.com). Now it lists that domain name, and even gives me a nameserver for it, ns1.mysite.com. Still I know I need to some how point my hosted domain from 000Domains over to this Virtual Server. I'm not entirely sure how to do that though.

Update 2

Since adding the domain to my VDS (see Update 1), my ipaddress to the VDS goes directly to the directory that the server made for the domain. It made a directory other than the one I had been working in, but that's fine. When I added the domain name, I set it as a Master, so now the ipaddress for the server goes directly to that document root for this particular project. I have changed the A name on my domain registration to point to my VDS's ipaddress. It's been a few hours and it doesn't appear to be loading from the VDS yet.

Update 3

Well it's been several hours since I changed the A Name to the new VDS's ipaddress. Nothing yet has happened. The domain name with 000Domains still goes to the old server, and accessing the ipaddress of the VDS directly takes me to the new server.

When I changed the A Name on 000Domains.com, I was told that I must disable forwarding on the domain if the A Name were to function properly. I now have "disable forwarding" and "pass subdirectories" checked, but again, it's been around 12-15 hours with no hint of a change.

When attempting to load a Kohana3 app onto my server, I was warned that mcrypt was not enabled. How would I go about enabling mcrypt on my CentOS server?

I'm planning on purchasing a virtual-dedicated server today and would like to pass a quick question by the community here before I do. I'm likely going to be getting CentOS, as that seems to be a pretty stable, and popular distro from what I can tell.

One of the companies I contacted (MediaTemple) mentioned they provide snapshots just incase I start doing something that could potentially cripple my server - I could always restore the last snapshot. Another company (GoDaddy) said they would provide routine snapshots once a day, week, or month and back it up to a remote FTP for me to download.

My question is this, is the "snapshot" capability provided in the OS itself? I'm not super-confident in my abilities yet to manage a server, so this functionality would be very attractive. Or, do I need to pick a host that provides this as an extra addon to the already rendered services?

My company is increasing in size, and our websites are picking up more and more traffic. We're currently using some low-cost shared-hosting, but have been experiencing downtime due to too many concurrent connections (limited to 200), enter Virtual Dedicated Hosting.

I have some experience with Linux, but limited to running basic commands to move, edit, delete files and directories. So, being a less-experienced user, I'm a bit shaken at the thought that everything will be on my shoulders. We're going to be running Apache, PHP, and MySQL.

What types of things should I be focusing on with regards to reading and learning. Any major errors new sysadmin's make when acquiring their own server?

I'm transferring files between servers and just started noticing that some of them are getting modified to be one long continuous line as opposed to having the returns and line-breaks they originally had. I'm assuming this has something to do with the transfer-type of my FTP Client which was originally set to "Auto," but sporting "Binary" and "ASCII" as additional options.

In short, what are the differences between the ways I transfer a file from one server to another, and will these differences be capable of modifying the file in such a way as I mentioned above?

Transfering FROM Windows TO Linux.

Today I noticed that I was unable to get a website to load up consistently, so I decided to look at the log files generated on the server. To my amazement, almost all of the files requested were having their paths modified, and not by the php-code that the site consists of. The site is hosted with GoDaddy.

Requests to /stories/rss was instead being made to VOadK/stories/rss or VgpUU/stories/rss. The random characters at the beginning change with each request it seems. I've never seen anything like this in my 10 years of web-development, so I'm at complete loss of what to do.

Does this sound like a server/apache issue? I've tracked the first offense in my log back to yesterday morning around 5am:

2009-11-30 05:07:06 -07:00 --- error: Uncaught Kohana_404_Exception: The page you requested, VUPWT/forums, could not be found. in file system/core/Kohana.php on line 841
2009-11-30 05:08:38 -07:00 --- error: Uncaught Kohana_404_Exception: The page you requested, YLPQR/css/reset.css, could not be found. in file system/core/Kohana.php on line 841

Note the random paths. Just prior to these lines in the logs, I saw requests for a file named 4273uaqa.gif. I have no files even remotely similar to this, so I googled it. What came up was interesting - references to the same file, including the random URL segments!

This has me wondering if I was the victim of a shared-server-hack. I am also using .htaccess, which does attempt to rewrite urls, so this may be of relevance:

# Turn on URL rewriting
RewriteEngine On

# Installation directory
RewriteBase /

# Protect application and system files from being viewed
RewriteRule ^(application|modules|system) - [F,L]

# Allow any files or directories that exist to be displayed directly
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d

# Rewrite all other URLs to index.php/URL
RewriteRule .* index.php?kohana_uri=$0 [PT,QSA,L]

Thoughts?

I'm doing a bit of research for work regarding SMTP servers. Basically, our company is bringing some work in-house that we've been doing remotely through other companies. We have the need to work with mailing lists, but I'm not sure how exactly to handle the great number of emails that will be sent out. From what I'm reading, many applications boast an "internal smtp, so you don't use your ISPs," but that just confuses me.

What exactly is an SMTP server, and how does it bypass my ISP? I can't seen to fathom how anything could make it from my network, to the recipients without taxing my ISP's servers. Can somebody shed some light on this?

I'm manually duplicating a few records and would like to paste the INSERT statements directly into Query Browser, but I have only ever performed one INSERT at a time with QB. Is it possible to insert, and run, 400+ inserts one after another without having to manually initiate each?

What's the easiest way to configure an apache-server (Running PHP/MySQL) to run on a thumbdrive? I've seen solutions that claim to do this effortlessly, but I've not had much experience with them. From the experience here, which solution is best for somebody who wants casual access for personal-use?