Zak's questions

I have several tables that are 10's of millions of rows, and have multiple indexes. When dumping and reloading the data it takes quite a while to reinsert because of the indexes, or to insert without indexes then re-index.

I understand that an index gives a database engine a quick way to locate a record on disk, and since a database dump and reload would or could effectively change the location of data on the disk, the index could potentially be invalidated. However, it still seems like you should be able to optimize a table by contiguously and sequentially locating all it's records on disk, then just have the index refer to a start location plus offset. Has anyone anywhere done any work on this type of thing?

Desired functionality: I could dump the data raw, load it in a sequential uninterrupted disk area, then just load in the indexes and tell the engine to update with the new table start position. After googling around on this, I see nothing...

Many months ago, while MySql 5.5 was still in beta this question was asked before. Now that it has been released and there are a few maintenance updates out, what do all y'all think?

According to the man page for resolv.conf, I should be able to specify a few options for how the resolver will resolve a given hostname for lookup: http://linux.die.net/man/5/resolv.conf

I know my nameservers are local and should respond quickly, therefore I want the timeout to be 2 seconds (maybe 1S). I also want to randomly swap which nameserver I will be hitting. So Ip ut together the following config according to the docs:

nameserver 10.10.1.15
nameserver 10.10.1.16
option timeout:1
option rotate
option attempts:1

However, it still takes about 5 seconds between each ping when I nerf my first name server entry :

nameserver 10.10.1.250
nameserver 10.10.1.16
option timeout:1
option rotate
option attempts:1

Further, I don't get the expected 5s, 1s, 5s, 1s delay I would expect if the resolver was round-robin-ing the requests between the first and second NS... Does anybody know why, or how to make it do what I want?

Thanks ...

I have a centOS5.4 server set that I have a "build script" for. The server runs as a webserver that runs apache+PHP for our proprietary app.

The build script, basically does a kickstart installation of the base OS and libraries that I need. I then have to go in and copy over the custom apache and PHP binaries that are built for our environment. Finally, I copy over our source code repository.

I have a couple problems with this, and would like advice on improving it:

1) If I build a new server, I want everything to be the same as the other servers. But at the time of install on the other servers I did an immediate yum update. If I do that currently on the new server, all kinds of libraries will be different.

2) Manually copying everything sucks. I'm about to build a shell script that will rscync and scp all the appropriate source code and config files, but I want to see if there is a better way first.

3) It would be ideal to create a disk dump image of the hard drive, then just DD that right onto the new server. BUT, for several servers, I am using software raid in mirror mode. Also, the hardware is slightly different. Does this matter? Will the mirror mode raid config just get picked up and rebuild the raid config on the second disk after I come back from boot? Will the other server hardware conflict with my base install?

Hopefully, someone comes out of left field here and just says, "No idiot, just user server clone enterprise 2k ++ ;) ". I would love that product. Thanks for your answers in advance.

I currently have some systems that multiple people have access to for administration purposes. We've modified the history log so that we capture 2k lines of history per user to help aid in who has done what on the system. However, we would additionally like to capture all keyboard input when we (the administrators) log in, and log it to a file so we can see what changes were made to files once people go into vi to edit them. It will also aid us in documenting when we are going through a compile of software and the like.

How can I do this? CentOS 5.4 if it makes a difference.

I'm pretty new to all the VMware world, so this is probably mainly a question about the right set of documentation to look at. I'm trying to clone/copy a VM that I installed on an ESXi installation.

I was trying to follow along with the top example here: Is there a way to clone an existing VM on an ESXi server without having to re-import it?

However, I'm using the vSphere client to connect to the ESXi box and manage it, and the vSphere client is telling me it won't let me rename the vmdk file.

The real answer I want is how do I clone the VM I installed if I want to spin up 5 copies. Is there another utility I can use to copy the vmdk file, then create a new virtual machine using it? Any idea why they nerfed the feature in vSphere client?

I have several sites in a /24 network that all get crawled by google on a pretty regular basis. Normally this is fine. However, when google starts crawling all the sites at the same time, the small set of servers that back this IP block can take a pretty big hit on load.

With google webmaster tools, you can rate limit the googlebot on a given domain, but I haven't found a way to limit the bot across an IP network yet. Anyone have experience with this? How did you fix it?

What software or system do you guys out on server fault use to remind you to do routine maintenance? How do you checklist and log the various items you are supposed to check? Do you have an internal process document? Do you have cron mail you every week with reminders to check system logs?

Also, do you work on a team to do system maintenance, and if so, how do you coordinate who will do what maintenance?

If you use a bug/issue tracking system to enter tasks, do you have a cron job enter recurring tasks?

I completed the following steps to generate my SSL cert request:

openssl genrsa -out key 2048
openssl req -new -key key -out csr

Then I submitted my csr to my signing authority, and got my cert back.

I put in in a file named "cert"

Now I want to verify that the cert is correct.

openssl verify cert

I get the original O and OU results back, but additionally I get the following error:

error 20 at 0 depth lookup:unable to get local issuer certificate

Am I correctly verifying the cert, and if so, why am I getting this error? If not, what am I doing wrong?

I have a web server image that I am responsible for building across multiple servers. I have a list of about 50 URL's that I am supposed to go to and confirm the correct content is showing up. Which automated tools exist to do this easily (without writing a bunch of curl requests and regexes in a script file) .

I wanted to figure out how to have multiple terminals (monitor, keyboard, and mouse) use a single centralized system. I guess at this point I can get computers for around $150, and use them as dumb terminals, but I would really like to centralize about 20 users onto 2 boxes of 10 each. Saving 2k would be nice. Has anyone done this before?

Note, all the users do is email/browse web using an internal web app that runs on another server.

Edit:

Also, I looked at disklessworkstation.com, but their "thin clients" are $200-$400. I can get a barebones PC for $150. I would be more looking for a $50 and/or under device that could talk on the network, or a way to throw more video cards and usb ports onto a server for I/O.

What are the steps needed to compile in support for syck into php 5.2.x on a 64 bit centos 5.3 system?

I haven't seen this another good FAQ on this, so I figured I would drop both the question and answer here since it took me a good while to figure out. If anyone appreciates, please upvote both Q & A so I know to keep posting things like this here.

I'm trying to get php5 to compile using libssh2. ./configure --help gives me no option on how to include the libssh files. also, if i try to phpize libssh, i get an error telling me no config.m4 file exists in the highest src directory of the project. That would be because there is no config.m4 file anywhere in the project for phpize to use.

How can I get libssh2 to compile in to php5.2.6 ?

This is on a new centos 5.3 64 bit OS.

I work at a dot com and part of our team's responsibility is to maintain the production web application and server farm. Only recently did our department even get created, and now we have a huge amount of catchup patching servers, and implementing monitoring and backups.

To start on this monster we've broken it down into phases, and as part of our first phase, we are reinstalling OS'es on several servers getting them updated from old Redhat 8 (not fedora 8) OS installs. As a webapp, the servers need to run apache and php. The modules that need to be compiled into these programs are documented, and an old build process for compiling is documented.

As sys admins, what do you guys out there expect to have documented, and what should you be documenting? Since both build process and documentation need to be updated, what is the best way to go about laying out the items that need to be done? Should defining the steps be part of the sys-admin's job, or part of the technical manager's job? Is this part of the qualification of being a "senior unix engineer" vs a junior engineer? What standard would you want to be held to evaluating your performance on a project like this if it would affect your performance review?

Edit: The application is under continuous development. A majority of it was written in PHP4 and continues to run on PHP4, however, a newer code running as a web service runs as PHP5. So on the same boxes there is both a php4 and a PHP5 installation. The modules required for each build are documented. The sysadmin has that doc.

I'm trying to run an OpenVPN VPN on an XP box. It works fine when I have a physical connection plugged in to the wired Ethernet port. However, when I try to run it with the wireless card as the primary interface I get a new connection created in my control panel that refuses to connect. Anyone have ideas?

I want to know if the box is Fedora Core 4 or Redhat 9, or CentOS, etc... not if it has Kernel 2.6.x

I've seen older f5's on ebay for about $500 for a pair. I've heard they work great for load balancing, but I'm trying to figure out what the ongoing costs for them are. Does anyone know what kind of licensing and/or subscription you need to get for these things to make sure the firmware is current? Or is there even a license required? Can I just buy for the $500, set up, and go?

I've used The Dude to map my network, but I can only export the network map as a graphics file. I've also used Dia and Vision to manually diagram portions of my network.

Does anyone out there have a solution where I can do automatic network mapping using a tool like "The Dude", then pull that file over to a manually editable format for cleaning up and/or enhancing in Visio or Dia?