
CentOS 7 released on x86_64 - priteau
http://lists.centos.org/pipermail/centos-announce/2014-July/020393.html
======
nailer
Woo. Have been using the RHEL 7 Amazon AMI images, and it's nice not to worry
about shell scripts / custom supervisord stuff for your web services anymore.

My node app is deployed with a single `myapp.service` file thanks to systemd:

    
    
        [Service]
        ExecStart=/usr/local/bin/node --harmony /var/www/myapp/server.js
        Restart=always
        User=nobody
        Group=nobody
        Environment=PATH=/usr/bin:/usr/local/bin
        Environment=NODE_ENV=production
    
        [Install]
        WantedBy=multi-user.target
    

Then:

    
    
      iptables -t nat -A PREROUTING -p tcp --dport 80 -j REDIRECT --to-port 3000
    

(since I run my app on a low port so it can run as nobody, and 3000 isn't
visible to the outside)

    
    
      cp myapp.service /etc/systemd/system
    
      systemctl enable myapp.service
    
      systemctl start myapp.service
    

This has all the stuff you expect:

\- Not restarting repeatedly if the app is bouncing up and down.

\- I can see how it goes with `journalctl` which reads journald messages, and
those messages come from a source called `myapp` rather than the old ancient
syslog facilities (local0, uucp, lpd) which everyone just ignored in favour of
grepping.

~~~
ck2
How do you do "configtest" and "graceful" with systemd/systemctl

(trick question, you cannot, use old init.d scripts)

~~~
Shish2k
How do you do "configtest" and "graceful" with old init.d scripts?

    
    
        # /etc/init.d/mysqld configtest
        Usage: /etc/init.d/mysqld {start|stop|status|restart|condrestart|try-restart|reload|force-reload}
    
        # /etc/init.d/mysqld graceful
        Usage: /etc/init.d/mysqld {start|stop|status|restart|condrestart|try-restart|reload|force-reload}

~~~
ck2
configtest and graceful are "commands" used by other scripts such as httpd
(apache) and nginx scripts which can take alternate signals to do other
actions

but even in your example, condrestart, try-restart, those aren't supported by
pure systemd scripts - however if you were using the init.d version you could
do the easy-to-remember/type _service mysqld condrestart_

Fortunately with 7.0 you can keep using the old init.d scripts and custom
commands, hopefully that will never go away with any of the later 7.x versions
(I don't see why).

------
kureikain
I always scare of CentOS/Fedora. Whenever I updated something, it will be very
old packages. Leading to use 3rd repo, and without any kind of document, the
next sysadmin will be in trouble. I used to install Gearman on Centos 5.9 and
it was a nightmare: the original 3rd repo didn't have gearman and I have to
use other repo which is complain about PHP-Common conflicting. Remi and
webtactic did help at the end.

It's hard to keep Centos Update to date with latest software IMHO.

I'm not an SysAdmin but I think the idea of APT and YUM is same but why it's
so hard/trouble to use YUM?

~~~
heroprotagonist
Besides using third party repos, you can also use Red Hat Software Collections
for the official Red Hat offering of more recent packages (requires RHN, not
available for CentOS).

[https://access.redhat.com/documentation/en-
US/Red_Hat_Softwa...](https://access.redhat.com/documentation/en-
US/Red_Hat_Software_Collections/1/html/1.1_Release_Notes/chap-RHSCL.html)

As another approach to mitigating dependency hell, you might consider using
Docker containers for your services.

~~~
sciurus
Software Collections are available for CentOS.

[http://wiki.centos.org/AdditionalResources/Repositories/SCL](http://wiki.centos.org/AdditionalResources/Repositories/SCL)

~~~
heroprotagonist
Very nice, thank you.

------
dimitar
"CentOS is an Enterprise-class Linux Distribution derived from sources freely
provided to the public by Red Hat." ?

It used to be from a "Prominent North American Enterprise Linux Vendor".
Something changed at some point.

~~~
andcase
They got official support is what changed.

[http://www.redhat.com/about/news/press-archive/2014/1/red-
ha...](http://www.redhat.com/about/news/press-archive/2014/1/red-hat-and-
centos-join-forces?utm_source=rss&utm_medium=rss&utm_campaign=red-hat-and-the-
centos-project-join-forces-to-speed-open-source-innovation)

------
btbuilder
I must say that compared with the CentOS 6 release CentOS 7 is a breath of
fresh air. I'll assume for the moment that this is because of Red Hat's
involvement in the process. Specically the availability of build scripts and
the openness of communication throughout the process.

The delay in releasing CentOS 6 and the delays in updates had me worried about
the future of CentOS.

~~~
greglindahl
The CentOS team completely re-did their build system at the start of CentOS 6,
and that was cause of the delay. This build system still has nothing in common
with Red Hat's build system, and it worked pretty well for CentOS 7!

------
scurvy
Now there are 2 kernel boot parameters required to get old style "eth#"
interface names. net.ifnames=0 and biosdevname=0

CentOS 6 only required biosdevname=0

~~~
ck2
Thank you for this! I was going crazy trying to figure out how to get "eth0"
back. Works perfect.

 _yum install net-tools_ is also a must

I think I've spent the first dozen hours with centos 7.0 just trying to get it
to behave more like 6.5

Having to remember to run a script every time I edit grub configuration is
annoying as hell too.

    
    
        grub2-mkconfig -o /boot/grub2/grub.cfg
    

I mean that is so natural and easy to remember, lol - I had to make "update-
grub" (like debian) an alias for it

------
sliverstorm
_512MB is the minimum memory requirement for CentOS-7_

Well. Dangit. Grumble grumble...

~~~
topbanana
There are quite a few choices of lightweight Linux distro. This isn't aimed at
that market

~~~
sliverstorm
Oh, I know, but I've been happily using CentOS 6 on my 128MB box, and was
looking forward to CentOS 7.

~~~
voltagex_
When I'm building tiny Debian images, I use debootstrap, which doesn't seem to
use much RAM at all.

There used to be a Fedora equivalent called febootstrap, but it looks like
it's mutated a bit since then:
[http://people.redhat.com/~rjones/supermin/](http://people.redhat.com/~rjones/supermin/)

You may be able to work around it that way.

Out of interest, what machine are you using CentOS 6 on? I find 128mb kinda
tight - although I've recently found a VPS provider who's managed to get
Debian Jessie working in 96!

~~~
stevekemp
Once upon the time I created "rinse" which is an RPM-using debootstrap-like
tool.

I've handed that off now, but the project is still very much alive:

[http://collab-maint.alioth.debian.org/rinse/](http://collab-
maint.alioth.debian.org/rinse/)

------
ck2
I can learn to adjust to systemd

But wow I cannot stand grub2, what a mess.

~~~
rando289
Agreed. Config files 100 times bigger and more complicated. Why? Go to it's
home page and find a link that says "differences between GRUB Legacy and GRUB"
which simply goes to the grub .97 manual which says absolutely nothing about
differences between the 2 versions. They really care about their users, that's
for sure.

~~~
mercurial
On Debian you usually stick to changing options in /etc/default/grub and don't
touch anything in /etc/grub.d.

------
freehunter
Is there something notable about this beyond just a new version?

~~~
geerlingguy
RHEL 7 was released on June 10[1], but many people (myself included) don't
have a RedHat subscription and run CentOS, the 'community' edition of RedHat.

Up until today, CentOS 6.5 was the latest release... so I can start using
CentOS 7 now and enjoy the benefits that RedHat introduced in RHEL 7. You can
see that the delay before CentOS releases a community version of RHEL has been
much improved in recent years in this Wikipedia chart[2].

Also, iirc, this is the first major CentOS release with the CentOS project
more or less under RedHat's wing[3].

[1] [http://www.redhat.com/about/news/press-archive/2014/6/red-
ha...](http://www.redhat.com/about/news/press-archive/2014/6/red-hat-unveils-
rhel-7)

[2]
[http://en.wikipedia.org/wiki/CentOS#Versioning_and_releases](http://en.wikipedia.org/wiki/CentOS#Versioning_and_releases)

[3] [http://www.infoworld.com/t/linux/red-hat-stamps-its-
influenc...](http://www.infoworld.com/t/linux/red-hat-stamps-its-influence-
centos-7-245673)

------
priteau
You can go to [https://git.centos.org](https://git.centos.org) which is
hosting all the sources used to build the system. Of course for RPM packages
that is only metadata, not the actual upstream software source.

~~~
justin66
Just out of curiosity, since it sounds like you might know: on ubuntu I can do
something like _sudo apt-get source packagename_ and the system will just
download the associated source code if a source repo is setup in the system's
sources list. Does RHEL/CentOS have a similar capability?

~~~
priteau
Yes it does. "yumdownloader --source package_name" will download the source
RPM. yumdownloader is part of the yum-utils package.

------
topbanana
I've never used RHEL. It doesn't seem prohibitively expensive. What advantages
are there over Centos, other than support?

~~~
derekp7
The support goes both directions. It is a way to get the organization you work
for to indirectly donate to a variety of free software projects, and your
company also gets the contractual safety net that they want.

~~~
Ologn
Yes. If you have RHEL installed on hundreds (or thousands) of HP/Dell servers
at a Fortune 1000 company, you'll have someone to call if the kernel on some
production machine keeps dumping.

I can see a bootstrapped company using CentOS, or a company running on
angel/seed money. Once a company gets Series A funding though, you have to
start wondering why they wouldn't upgrade to Red Hat. The message from the
company basically is they'd prefer the sysadmin to spend their nights and
weekends figuring out problems, instead of making a small payment for support
service. This is the type of position you want to run, not walk from.

On a job interview, a good question for a sysadmin to ask an interviewer when
they say "do you have any questions to ask me?", is, "Will I support any
machines, operating systems or applications that are not under a vendor
support contract?" Inevitably there will be one or two legacy machines or
applications, but if you get a laundry list in response, run.

~~~
mgkimsal
"The message from the company basically is they'd prefer the sysadmin to spend
their nights and weekends figuring out problems, instead of making a small
payment for support service."

So... if there's a friday night problem, you'd prefer staff to just be
hanging, chillin' at home, and then when pressed, say "we created a ticket
with redhat, nothing more to do!" ?

Critical breakages should keep people working until stuff is fixed. If you
want to also pay a bit extra and involve external support people, that's fine,
but it's not a magic bullet that just 'fixes' everything. You've now got to
account for time to manage working with external support staff, making sure
you can get them in to the affected systems, etc.

~~~
scott_karana
That's a false comparison.

If a machine is kernel dumping, and Red Hat is trying to diagnose and fix the
machines, nobody said your sysadmins will automatically just go home.

Instead, they can use their time more productively: making a
secondary/workaround, or figuring out ways to re-architect your solution
around the failure points.

------
pippop
I have loaded centos 7 onto laptop and I can't get into it its asking for
localhost and password when I put it in it repeats

~~~
keithpeter
Post the link to the ISO you installed from.

------
stplsd
Will I still be able to run commands like service mysqld start, etc?

------
pippop
Can't get into cent is 7

------
qstyk
Am I missing something? This was submitted two hours ago, yet the images
(CentOS-6.5-x86_64-bin-DVD1.iso) are the same that I had downloaded on
6/20/2014\. The release notes list the new image names, but they don't appear
to be pushed out to the mirrors.

~~~
pgl
Check here:
[http://isoredirect.centos.org/centos/7/isos/x86_64/](http://isoredirect.centos.org/centos/7/isos/x86_64/)

There's quite a few mirrors with images. However, they do recommend torrenting
the images:

[http://lists.centos.org/pipermail/centos-
announce/2014-July/...](http://lists.centos.org/pipermail/centos-
announce/2014-July/020393.html)

