Posts by DimaYasny

When Cassandra is getting heavy, all you need do is migrae to ScyllaDB. You'll never want to look back

Been using thinkpads since 2008, it's perfect for Linux, all the devices work, and Lenovo, surprisingly, didn't break the compatibility after taking over.

VMWare ESXi open source? These two things do not go together.

RHCE is more than just a paper, it's a practical exam you cannot pass by cramming braindumps (have you heard a 5 year old just passed MCSE? shows how valuable that one is...)

RHCE opens up pretty much every Linux related position, because, while it's being oriented around Red Hat, the actual knowledge is applicable on all distros and it's the only certification that is really reliable and cannot be obtained without knowledge and experience.

KVM is a mature technology, having been accepted into the Linux kernel back in 2006. It's also the most efficient of available hypervisors, using the Linux kernel directly to interact with hardware instead of piling multiple kernels on top of one another (like Xen/hyper-v) or running through an extra translation layer like vbox or vmware workstation. KVM is pretty easy to use on the desktop with virt-manager, and it has a datacenter and cloud solution available - oVirt (and commercially RHEV) easily compete with vsphere and openstack is the cloud solution everybody uses (over 80% of openstack deployments are with KVM).
So if all you want to do is play with some OS's locally, it doesn't matter what you use, but once you start to scale, both in terms of deployment size and in terms of performance, KVM is definitely the way to go.

if 10Gb RAM is your concept of "monster", you haven't seen serious hardware. I've run Linux servers with 256 cores and 2Tb RAM with no issues.

Hi All,

I am trying to start writing a wiki-ish CMS I've been contemplating for a while now.

the content will include pics, html content, and should be stored in a database (the current pick is postgres)

A few questions for the more experienced folk 'round here:
1. how do I plan such a database - is there a ready-made data type for a webpage, or do I need to build a table for every component (e.g. pictures). Is there a ready template for such a thing?
2. Python web frameworks - which would be best suited for this? Django is something I'm reading about right now, but there are pylons and turbogears as well
3. The postgres connector - which one is the more popular and the better maintained one? I'm using psycopg right now, but this early in the process, it's easy to switch to another package, if this one is suboptimal.

Any opinions and tips appreciated. I really want to get this project right, so when I open it up, I won't need to blush :)

Thanks,
D.

What you need is an CAS server in the DMZ, exposing the needed ports

RHEV has already been adopted by several major players, including IBM. So this is old news, the "new" news is the recent RH summit, and the GA release of RHEV 2.2

With today's computers, there is no problem to run windows in a virtual machine on top of linux. all the distributions include libvirt+virt-manager nowadays, and there's no restriction to install virtualbox or something similar

When you get a "Blue Screen of Death" (BSOD) error and your PC WON'T boot, Microsoft has NO CLUE what causes it other than remove your hd cable and re-seat it (Come on man, is THAT the best they can come up with for a solution??? AND it's THEIR operating system???)

This is totally wrong. 1st of all, BSOD's can be troubleshooted, they usually relate to drivers and hardware issues
second, install CD's and repair partitions are everywhere, especially on brandname PC's and servers.

If your hard drive is still working, you should NEVER have to RE-FORMAT your drive and even if you had to as a last resort, you HAVE the installation CD to be able to.

Reinstalling desktop versions of windows is normal practice at least once every year. This is due to the way windows registry works, getting cluttered up at some point or other.

This sort of thing (selling computers WITHOUT installation CD's) ought to be illegal because it causes so much frustration and it just shouldn't be like this.

As I said - all preinstalled systems have a way to get back to the original state. If you don't know how to use it, that doesn't mean it doesn't exist.

I had my PC custom built with TWO hard drives, a 120 GB for my operating system and the other drive, a 320 GB ONLY for my data/applications so in the event I have an operating system problem, 1) my data …

thanks guys, we've solved it after some extra poking around :)

should have a couple of other questions tomorrow though, if you don't mind

and I'll attach the .ui file next time

Hi guys,

We're writing a GUI based on PyQt, and we're running into an issue when using different resolutions.
Problem is, we can't find how to get the GUI elements to automatically resize when the window is resized, or when the GUI is running on a larger resolution than the one the GUI was originally developed in

I'm using Qt-designer to create the .ui files, if that helps

Thanks nezachem, I do feel that the fuctions aren't exactly set up the best possible way, and I'll add the leading "/" checking as well.

//the girl doesn't want me to give her a one line solution - something like

ls -s myshell /bin/sh

:)

Thanks Nezachem! I have changed quite a lot in the code, and now it does work, with a few exceptions unhandled (like segfaults when getting a permission denied), but those were not mentioned in the assignment anyway.

My main problem was with line 6, where I changed char *com[] to char* com[50], and that started working. I still have no idea why, this being far from my area of expertise, but the girl says she knows why, and that's good enough for me :)

strtok() was a requirement for this assignment, as well as execv(), can't do much about it.

I'm going to dwel on the man pages for wait() now, posting the current working version, in case you have the time to have a look and suggest improvements

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<errno.h>
#define n 50;
#define str [n];
#define str_eq(s1,s2)  (!strcmp ((s1),(s2)))
void get_path(char *);
char *get_line(char *line, int size);


char *get_line(char *line, int size)
{
   if ( fgets(line, size, stdin) )
   {
      char *newline = strchr(line, '\n'); // check for trailing '\n' 
      if ( newline )
      {
         *newline =  '\0'; // overwrite the '\n' with a terminating null 
      }
   }
   return line;
}

void get_path(char cmd[50])
{
    char command[50] = {0} ; //full command with path included
    char *tempcmd = NULL;
    char *commandptr = NULL;
    char *result = NULL; //path iterator
	char* com[50]; //command with args, no path
	char *arg = NULL; //list of arguments, path and command excluded
	char delims[] = ":"; //path …

Thanks, but the article uses execve, which is not an option for me in this case.

I was just looking for an explanation for line 46, 52 and 54 in my code

Hi all,

I'm helping my girl out with her hw, (/me not knowing C at all, but someone has to help, right?)
I am supposed to read user input, and then try to execute a given command plus the arguments in every given $PATH.

I managed it all, but I get puzzled by the execv function, which I am supposed to be using, it doesn't produce any stdio, and I can't seem to find a way to make it work

a basic command

execv ("/bin/touch", "/tmp/test123", NULL);

doesn't do anything, neither do I see an exit code.
How do I use it?

Here's what I've got so far:

void get_path_exec(char cmd[50])
{
    char command[50] = {0} ; //full command with path included
    char *tempcmd = NULL;
    char *result = NULL; //path iterator
    char *com[] = {0}; //command with args, no path
    char *arg = NULL; //list of arguments, path and command excluded
    char delims[] = ":"; //path iteration delimiter
    char delims1[] = " "; //
    char * path; //variable to hold the full path delimited by ':'
    int pid, status; //process flow control
    int argcount = 0; //argumetn counter, where 0 is the command
   
    tempcmd=cmd; //assign to temp variable, so strtok doesn't ruin cmd
    path=getenv("PATH");
    if (path != NULL)
        printf("Path is %s \n", path);
    else exit(1);    
	
    arg = strtok( tempcmd, delims1 ); 
    com[0] = arg; //place the command into com[0]
    while( arg )
    {
	  argcount++;
	  arg = strtok(NULL,delims1);
	  com[argcount] = arg;
	  printf("arg …

the server also requires a static IP address

windows XP is not a server level OS, more so, it is not supported by server vendors on their server hardware.
You can always get a simple desktop PC for that, but I wouldn't use a hoe PC as a serious production server

well then, you have to take your chances with the not so well tested software.

There are bugs everywhere, where there is software actively developed :) if you want an OS with a small amount of bugs on your desktop, stick to RHEL Desktop edition. No bleeding edge software, but it works nicely.

fedora 11s installer is crap. Crashes all the time during partitioning, generally bricking windows in the process. fedora is so buggy.

worked for me every time I ran it - on lg, hp, dell, lenovo laptops, different desktops and quite a few VMs...

what am I doing wrong? ;)

...and better enterprise grade hardware support makes it better for companies

MS ran hotmail on FreeBSD between 1996 and 2003. Worked fine for them.

MS isn't much of an example where OSS comes in

Yahoo also (still) run on FreeBSD as do big names like Sony, the Apache foundation and Netcraft.

they are also using qmail, which is deprecated everywhere.

I agree that it indeed an excellent choice for servers.

it used to be before kernel 2.6 for linux came along. but Linux is nowadays much farther ahead than BSD.

I know you asked for a linux OS but why not FreeBSD? I'm setting up my own server and i was adviced to use it as an excellent choice for my purpose.

ever considered why freebsd is not widespread in corporate server setups?

Thisara asked for a free Linux so RHEL can't be suggested. Maybe CentOS (it's a Red Hat rebuilt) could be a good choice or Debian stable as suggested by ryuslash. Ubuntu server is based on Debian and could be a valid solution. My suggestion is to install the distribution that you are most familiar with.

Who said you can't get RHEL for free? support and RHN cost money, Linux is free

RHEL5.4 of course.

Fedora for me. the speed of response to BZs is the best I've seen, and everything works out of the box, without trying to be like windows (like ubuntu/pclos/opensuse do)

tried to switch to fedora from ubuntu several times, and though I did get my laptop working fine, it was not an out of the box experience, like it is with ubuntu. maybe ubuntu has better support for Dell specific laptops though :)

I've got to switch over to a RH-like distro because of work, will probably go for F10 this time, and stick to it

a guy in Egypt went to prison for something he wrote in his blog a few years ago

well, I've never liked KDE because I've always had to use 3 typing languages, and KDE is very hard to set up properly for that, while gnome is as easy as windows in that aspect. as for everything else on the desktop linux side - I've never done much, I prefer doing things the right way - from the console. So as long as the GUI is capable of running the usual set of desktop apps, and has the right features for me - I will use it. In this aspect gnome has been my choice mostly because of the language switch issue

well, if ESX goes open source, and provides a community edition, like, for instance Zimbra does, and stops being so secretive - microsoft will go down in the virtualization market for good. that is the problem with vmware - the server software is very hcl strict and even more closed-source than windows.

whoa! could be a winner

linux is much harder to support, ans support people for linux cost much more than simple windows guys.
also, just like mcdonalds with the "careful, hot!" thing written on it's coffee cups, del is trying to make sure whoever is buying a linux machine will not come back complaining he can'r run his games or software there.

Note the fact that MS aren't mantioning any particular patent. Just obscure sayings, nothing more. This is a PR trick to scare businesses from switching over to Linux, because vista is such a failure. The exact same trick was already played out by MS in 2004, and it did manage to slow Linux down, a little bit. But these days - no way.

4. it's a Debian core, so it's relatively stable

the core is based on debian unstable/testing.

I find Fedora too buggy.

buggy how? I've been using it instead of ubuntu for quite some time now, and yes, there are bugs, but they are being fixed very quickly. considering the fact that some of the best Linux developers work for Red Hat contributing to Fedora, I'd prefer Fedora over Ubuntu any day

logs, output, details, steps attempted?

What you should do is call in a professional, and pay the man for a one-off service. Nobody will really walk you through everything without seeing your setup, since blind work is much harder and too time consuming to take on, especially on a voluntary basis.

Call a pro, ask him to explain everything he does, and take notes. You will end up with a working setup and the knowledge of where you went wrong, so next time you will not need help

I'm no expert on HP controllers, best guess would be to get the exactly same type of drives you already have

as for the Dell 36Gb disks... that's not much space at all, and those drives are OLD. Probably about to start dying anyway. Especially if they are maxtors

ok, what you do is
1. insert the new drives (should be hot-add iirc)
2. go into the raid controller utility and create a new raid array over those new drives. you can insert 3 drives, use 2 as raid1, and the third as hotspare for instance, or you can create a raid5 out of all three
3. go into the disk management of windows, initialize the new volume and create partitions; don't forget to format the partitions so they're usable

a BIG note: if you're not familiar with these actions, you're much better off calling HP server support, and having them guide you through the process. They have the equipment in front of them - I don't

I presume you have a raid-1 in there with the original two drives?

man nmap

good point, I tend to be too Linux focused :)

you might need a bios update

definitely local.

I've worked in UK/I, Russia, East Europe and Israel, and such an assumption is never even made

I think I would stick to the virtuozzo then. :) Thanks.

openVZ _is_ virtuozzo :) Open-V(irtuo)Z(zo)

just the community version :)

you had iptables working, haven't you?

ITERATIONS=1000
for i in `seq $ITERATIONS`; do mkdir /dir/subdir$i ; done

Any multitabbed version of Windows CMD.exe?

no. why use windows anyway?

do you have a LAN and a wifi card in there? sounds like you either don't, or the drivers aren't installed