CentOS7

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MoonWolf
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CentOS7

Post by MoonWolf » 2013/12/13 11:37:24

No, it's not 'when it's out'-like question. It just kicked me yesterday that RHEL7 Beta is out and i'm in the middle of big (as for me of course) migration (about which i maybe post a few word when it's done). So i'm concerned a little. Maybe i should wait until CentOS7 is out? RHEL7 is somewhat like new Fedora (say 17, 18) which i'm using right now and used to it (systemd for example). So it has modern KDE (and desktops also are part of my migration).

I know CentOS6 is stable, usable and cute. But it bugs me that i'm installing 'not newest' system. Also it has issues (old kernel - old drivers, it kicked me once) On the other hand it works, and i may continue using it for (say) next two years and switch to CentOS7 with hardware change. As Fedora (and RH from 7.1) user i'm used to use newest available software - maybe i should get rid of this habit...

Just few words from confused (part-time) admin (;)
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TrevorH
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Re: CentOS7

Post by TrevorH » 2013/12/13 11:42:44

If the RHEL7 beta follows the same course as el5 and el6 then the GA is about 6 months away.
CentOS 6 will die in November 2020 - migrate sooner rather than later!
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
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MoonWolf
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Re: CentOS7

Post by MoonWolf » 2013/12/13 12:03:23

Well, theoretically i could wait.
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assen
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Re: CentOS7

Post by assen » 2013/12/16 20:24:04

Hi,

You can always give RHEL7Beta a try, it is available on RedHat's FTP. A few words of caution from my experience so far:

- It comes with Gnome 3. This is a whole new paradigm for most users - and most users don't like large shifts in their user experience. The so-called 'Classic' Gnome is just a poorly masked Gnome 3 using a Cinnamon-like skin. Expect a lot of rant here (just like if you migrated a Windows user to ver. 8 without the 'classic' Windows interface option).

- It won't work on anything older than 3 years. RedHat have decided to throw away from the kernel a huge number of drivers, so you'll need 2010+ hardware to run RHEL7. It is enough to take a look at which NICs won't work, both wired and wireless (and that's a huge list). This may not only affect your desktop users, but also entry level servers if you have such. Adding the missing drivers back to the kernel will keep many people busy for months after GA.

- It comes with a bunch of new stuff, much more drastic change than from RHEL 5 to 6. Systemd is by far the biggest one, but if you like it, then no problem. Also Apache 2.4 will step in with new authentication/authorization modules which are guaranteed to break any running setup; make a proper evaluation if you don't want to be stuck for days fixing configs (inlc. users' .htaccess files). And yes, the new interface naming convention will surely kill any non-RHEL-provided tools which believe everything under the Sun is ethX, so get ready for this too.

IMHO, the only two good news in RHEL7 are XFS out of the box and Samba 4. But for me. so far then cannot prevail.

WWell,

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MoonWolf
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Re: CentOS7

Post by MoonWolf » 2013/12/17 13:11:20

assen wrote:Hi,

You can always give RHEL7Beta a try, it is available on RedHat's FTP. A few words of caution from my experience so far:

- It comes with Gnome 3. This is a whole new paradigm for most users - and most users don't like large shifts in their user experience. The so-called 'Classic' Gnome is just a poorly masked Gnome 3 using a Cinnamon-like skin. Expect a lot of rant here (just like if you migrated a Windows user to ver. 8 without the 'classic' Windows interface option).
On desktop i prefer KDE, so GNOME is no problem for me.
assen wrote:- It won't work on anything older than 3 years. RedHat have decided to throw away from the kernel a huge number of drivers, so you'll need 2010+ hardware to run RHEL7. It is enough to take a look at which NICs won't work, both wired and wireless (and that's a huge list). This may not only affect your desktop users, but also entry level servers if you have such. Adding the missing drivers back to the kernel will keep many people busy for months after GA.
As for hardware - fortunately my (so-called) servers are quite new - there was/is fedora working on them.
assen wrote:- It comes with a bunch of new stuff, much more drastic change than from RHEL 5 to 6. Systemd is by far the biggest one, but if you like it, then no problem. Also Apache 2.4 will step in with new authentication/authorization modules which are guaranteed to break any running setup; make a proper evaluation if you don't want to be stuck for days fixing configs (inlc. users' .htaccess files). And yes, the new interface naming convention will surely kill any non-RHEL-provided tools which believe everything under the Sun is ethX, so get ready for this too.
Ironically new authentication in apache and samba4 was my primary reasons for dropping Fedora. I found a replacement for apache authentication. And workaround for samba also, but in a way i don't like.

So - i think i'll stick with CentOS6 (especially that migration hasn't been completed yet) and consider upgrade with hardware change. Of course install RHEL7 on VM looks like good idea too.
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Re: CentOS7

Post by keithpeter » 2013/12/26 16:09:05

assen wrote:...RedHat have decided to throw away from the kernel a huge number of drivers, so you'll need 2010+ hardware to run RHEL7. ...Adding the missing drivers back to the kernel will keep many people busy for months after GA.
Hello All

Running the RHEL Beta on an old laptop with wifi that needs Ath5k driver so no native wifi. Fortunately the wired connection is fine and a Netgear WG111v3 USB wifi dongle works fine as well (rtl8187 driver present in red hat kernel, even though the rt8187 driver is listed as one of those removed). All seems fine, no odd behaviour or freezes or anything.

Any pointers as to how one goes about adding a driver back into the kernel?

(for now I'm using an EPEL kernel for when I don't want to keep track of the dongle, and the red hat kernel with dongle when actually testing the beta).

PS: I wonder how many client PCs/laptops are new enough to run 64 bit OS but old enough to require a removed driver? Perhaps that could have been part of the thinking behind the removal of a lot of drivers for older cards?

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Re: CentOS7

Post by toracat » 2013/12/26 19:18:53

keithpeter wrote: (for now I'm using an EPEL kernel for when I don't want to keep track of the dongle, ...
Perhaps, you meant ELRepo kernel-ml/kernel-lt? :)
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Re: CentOS7

Post by keithpeter » 2013/12/26 19:39:51

toracat wrote:
keithpeter wrote: (for now I'm using an EPEL kernel for when I don't want to keep track of the dongle, ...
Perhaps, you meant ELRepo kernel-ml/kernel-lt? :)
Oops, yes, I did, well caught. I'm using the lt one

Code: Select all

keith@localhost ~]$ uname -a
Linux localhost.localdomain 3.10.25-1.el6.elrepo.x86_64 #1 SMP Fri Dec 20 15:25:47 EST 2013 x86_64 x86_64 x86_64 GNU/Linux
but I'm hoping an update-proof way of adding in the older drivers appears for the default kernel when CentOS 7 pops out...

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Re: CentOS7

Post by assen » 2014/01/01 14:04:35

Hi,
keithpeter wrote:but I'm hoping an update-proof way of adding in the older drivers appears for the default kernel when CentOS 7 pops out...
This is going to be a little tricky. The main reason is the way RH deliver their kernel: normally (e.g., on Fedora) inside the source RPM you'll find the vanilla kernel plus all patches. However, the source RPM for the RHEL7beta kernel contains an already patched tree. Still, from it one can conclude that RHEL7beta kernel is based on original 3.10.0 kernel. The most suitable way of adding drivers will be using DKMS (see http://wiki.centos.org/HowTos/BuildingK ... 3f927731f0). The path will roughly go like this:

First, get the binary kernel RPM file for your architecture; from it, extract the config file and save it (DKMS will need it)

Next, get the source RPM and install it locally; go to the ~/rpmbuild/SOURCES directory and copy the kernel's tar.xz file somewhere else, e.g., /usr/local/src; unpack it there. You will actually need to build the kernel once (using the extracted config file - don't install it, just build it), because DKMS needs some binary tools which are being built during kernel compilation.

Next, get the vanilla 3.10.0 kernel from kernel.org; unspack it in /usr/local/src too.

Next, in the vanilla kernel tree find the directory with the driver you need and copy it to /usr/local/src. Get inside and create the DKMS config file as per the Wiki above.

Install DKMS (yum install dkms) and read the man page. You will need the --sourcetree, --kernelsourcedir and --config options. The kernel version (-k option) is 3.10.0-54.0.1.el7

If everything goes fine, you should now be able to build off-tree the kernel module you need. You can even automate this task for future kernel updates (note that the version will change with each update, hence change the -k argument to dkms). Thus you'll be always running the latest RH-provided kernel with your custom build module for it.

WWell,

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Re: CentOS7

Post by keithpeter » 2014/01/04 14:11:18

@assen

Thanks for that 'bird's eye view' of the process needed. I used your post as a guide to reading some of the CentOS wiki pages and used the 'rpmbuild' approach. All very educational for me.

I discovered that the srpm for the RHEL kernel actually contains the source code for the ath5k driver, it is just the config file that needed changing (make menuconfig after make oldconfig) at the kernel building point so that ATH5K is being built as a module.

The resulting rebuilt kernel rpm boots ok and recognises the wifi card in this old Thinkpad that I'm using for testing. No significant changes were needed to the kernel.spec file unlike in the CentOS 6 based wiki page, just the adding of the architecture in the first line and an appropriate name in the %define line.

So I'm now doing some more reading and trying to build just the .ko module to add that to the original kernel, and then trying to see if the dkms packages from an el6 repo will install and work.

PS: actually building the kernel on a thinkpad X61s core duo 2 laptop needed about 3 hours and around 15Gb of hard drive space. I was quite surprised about the hard drive space as this system is on quite a small 'testing' partition :twisted:

Thanks

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