Software Archive
Read-only legacy content
17061 Discussions

CentOS 7.3 ... what a pig

Rob_J_
Beginner
553 Views

In preparation for the arrival of my new 7290 system I decided to gain a bit of familiarity with CentOS 7.3 so installed it in parallel with my Windows 7 installation. I used the CentOS-7.3-x86_64-Minimal-1611.iso for this exercise. Below are some of the issues faced:

1. Can't install it at all with an NVidia card in the machine. Workaround is to edit EFI\BOOT\grub.cfg on the install media and add rdblacklist=nouveau nouveau.modeset=0 in the first 10_linux menu entry.

2. Windows didn't appear on the grub2 menu when rebooted. I searched the internet for hours on this one. Many sites showed how to manually add menu entries, but this was a complete red herring. CentOS can't possibly find an NTFS partition without the ntfs-3g-2017.3.23-1.el7.x86_64.rpm package installed, and it simply wasn't included. Even after installing it the menu item doesn't appear. Yes, I can now read NTFS drives. Yes, the menu entry is now visible in boot.cfg but it just refuses to display in the boot menu.

At this point I gave up, to find that my usual trick of rewriting the MBR didn't actually hand back a pristine bootable Windows 7 system. After several more hours of fooling around I managed to recover the original setup, more by luck than skill.

The installation menus were confusing and required much deliberation. Wifi networking didn't work at all. What an utter piece of junk.

Thankfully I won't need to dual boot on the X200 so maybe it will be a better experience. Although frankly I'm inclined to build a Ubuntu 17.1 version of the tools and dispense with the damned thing completely. I hear that Ubuntu runs about 20% faster too.

 

0 Kudos
13 Replies
Rob_J_
Beginner
553 Views

After calming down for a few days and finally taking delivery of my X200 development system I decided to give CentOS 7.3 another chance. After all, this is the standard operating system for those of us too impecunious - or too stingy - to pay for RHEL or SLES so I was just going to have to become accustomed to it, warts and all.

Figuring that many of my troubles were caused by using the minimal version, I downloaded CentOS-7-x86_64-LiveGNOME-1611.iso from the Swedish mirror site, burned it onto a known reliable 8GB stick and rebooted.

And rebooted. And rebooted.

After about five tries I noticed some text flashing by, saying something about squashfs and not being able to find inodes. Damn it, I had a bad download. Got a second copy from another mirror but now my USB stick couldn't be reformatted, so I dredged out an ancient 4GB stick that had seen better days and loaded it onto that.

This time it worked.

Now, setting up partitions under CentOS is a nerve-wracking experience. I've been around since the days of wire core memory and I can't recall a worse piece of software than the CentOS installer, and that includes the bizarre low-level formatting utilities that came with the Sirius 1 / Victor 9000 PC of 1982. I had already installed the minimal version, but now the partitions I made for that were in the way and CentOS had no way to remove them.

Rebooted into good old Ubuntu and fixed it with gparted. And grinned to myself that my prediction of such things happening and installing Ubuntu first had saved me a lot of grief.

This time it all worked. Well, in a fashion. I now have a pretty GUI interface instead of having to remember all those arcane shell commands. However, wireless networking is still as broken in this version as in the minimal build.

I had merely put lipstick on a pig.

 

0 Kudos
Rob_J_
Beginner
553 Views

So as not to interrupt the flow of the above tale I omitted a few side facts. One of them was the intermittent inability to boot with grub on both machines, which took quite a while to figure out. It wasn't until I unplugged both the external SDD drives that it would work, leading me to believe that the stupid thing was assigning the wrong drive to them. If it's trying to boot off sda1 but one of the external drives has been assigned as sda there's no way it will work.

Much as I hate Windows, Linux is far worse. It's purposely obscure, frobbity and wastes productive time.

I won't trouble the reader with the other parallel weirdnesses that occurred; that would just be gilding the lily.

0 Kudos
jimdempseyatthecove
Honored Contributor III
553 Views

Windows has the same shitty problem when doing an install/major update if you mistakenly leave an external (USB in my case) drive plugged in. My wife's computer ended up with the system drive on (as) H: IOW without the USB drive plugged in, a system reboot to the only SATA drive resulted in the system drive being assigned drive letter H:

Jim Dempsey

0 Kudos
Rob_J_
Beginner
553 Views

Not quite the same thing Jim. At least if you assign a drive letter in Windows it sticks and doesn't change between boots. You can easily fix the issue mentioned in the Disk Manager. I always assign optical drives as V (for DVD) and R (for CD-ROM) to keep them out of the low end of the alphabet and leave space for USB sticks.

The larger issue is, of course, how to enable wifi with no cabled connection. Red Hat separated the main network code from wifi years ago and never got around to finishing the job. Seems silly that regular desktop OS builds are more advanced than a so-called "professional" system. The standard fix always starts with "yum install xyz" which does me no good at all here on the yacht with only 4G.

 

0 Kudos
Rob_J_
Beginner
553 Views

Found a solution to the wireless dilemma at last.

There's an ethernet to wifi bridge product available on eBay for AU$24.49 and I just ordered one about half an hour ago. Should be here by the end of the week. With that I can download and install the Network Manager, Network Manager Wifi and all sundry bits to get the USB wifi dongle operational. A handy gadget indeed.

https://www.ebay.com.au/itm/Bridge-VAP11G-300-Cable-Convert-RJ45-Ethernet-Port-to-Wireless-WiFi-AP-Vonets-AU/142626153800?epid=12011472045&hash=item21352e6548:g:x38AAOSwH-daM9ID

 

0 Kudos
Rob_J_
Beginner
553 Views

Tried to install Parallel Studio yesterday. Came to a dead stop when I discovered that GCC isn't even included with CentOS. I'm going to need a network connection for that one, trying to do it manually leads to Linux dependency hell.

Words fail me.

0 Kudos
Rob_J_
Beginner
553 Views

Today I was working in my Dell T7610 system, which dual boots between Windows 7 and Ubuntu 16.04.4 and the wifi was playing up badly under Win7. As I sometimes do when this happens, I plugged the 4G router into a USB port to use a direct connection. After a while I rebooted into Ubuntu and noticed that I still had a wifi connection. It occurred to me that this might also work under CentOS so I hastily moved the cables around and rebooted into the X200 system.

Today, right now for the first time, I am online from CentOS. Wifi doesn't work but it does recognize ethernet over USB. Looks like I wasted $25 on that other gadget but I'm so happy right now it doesn't matter. Now to install GCC and Parallel Studio.

 

0 Kudos
Rob_J_
Beginner
553 Views

Installed GCC and Parallel Studio, then made the stupid mistake of checking the "Install Pending Upgrades" box when logging off. I got upgraded to CentOS 7.4 on reboot and had to wipe the whole thing and start again. Oh well, it's a good way to become familiar with a new OS I suppose.

Anyhow, I've now achieved my goal for the Easter weekend. It's up and running. I did a quick test with lukminer and found that it runs 12.5% slower than Ubuntu 16.04 at a hashrate of 2,310H/s. Since I don't plan to actually mine with this box it doesn't concern me at all.

The more pressing concern is the 18% speed loss due to the bios, which I'll be following up next week.

 

Installing Parallel Studio was a bit quirky. The install_GUI.sh script wouldn't work for me at all, kept complaining of missing stuff without saying exactly what it needed. The install.sh script went better, at least telling me that it was looking for missing 32-bit libraries and giving the option to carry on anyhow. A bit odd considering 32-bit is no longer supported. Oh, and supplying a path to the licence file didn't work either, I had to open it with gedit and supply the licence key.

Still don't have the wifi dongle working but it's no longer urgent.

0 Kudos
Rob_J_
Beginner
553 Views

Ridiculous CentOS problem of the day:

There are no prebuilt drivers available for the MT7601U wifi dongle. It was added to the kernel at version 4.2 but not back-ported to earlier versions. That in itself isn't much of an issue since I could just build it myself from sources. What is a nuisance is that

/lib/modules/3.10.0-514.el7.x86_64

is an empty directory, and any attempt to install kernel development headers, such as

yum install kernel kernel-headers kernel-devel

gives me the wrong versions, to wit the -693 kernel. In other words, it's trying to silently upgrade me to a later kernel, which I believe may cause issues with Parallel Studio. I also tried requesting the correct version specifically but the repository no longer has it.

It's a good thing I'm a patient man because this is the sort of thing that drives people to drink.

 

0 Kudos
Rob_J_
Beginner
553 Views

With a bit more research I found the correct files at

http://vault.centos.org/7.3.1611/os/x86_64/Packages/

and will install them manually. I hope the dependencies that were updated, notably the kernel firmware and dracut (whatever that is) won't cause any issues.

 

0 Kudos
Rob_J_
Beginner
553 Views

Blast it, the driver wouldn't build. Linux, you gotta hate it.

 

0 Kudos
Rob_J_
Beginner
553 Views

It's now 8:30am here and I've been working on the wifi issue since 8:30pm last night. The level of help on Linux forums is ridiculously low. Everyone has an opinion but they rarely understand the question before setting fingers to keyboard, and thus there are thousands of pages of bogus, unhelpful and often completely erroneous or mischievous responses to almost every issue under the sun. It's like Reddit for nerds.

Eventually I built the driver successfully. Eventually I got it to install, and become visible with iwconfig. Eventually I gave up asking myself why Network Manager thinks it's a hardwired connection and just concentrated on the task.

There is ONE and only ONE way to make wifi work under CentOS, and that's to use wpa_supplicant. If I hadn't been familiar with it through playing about with Raspberry Pis I would have overlooked this option, because it's damned complicated and involves writing scripts and doing superuser stuff. But that was the answer.

If anyone need a driver for the MediaTek / Ralink MT7601U wifi dongle, just ask. I'm using it right now.

 

0 Kudos
Rob_J_
Beginner
553 Views
[coinstash@landing ~]$ ifconfig
enp4s0f0: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
        ether <private>  txqueuelen 1000  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
        device memory 0xfb120000-fb13ffff  

enp4s0f1: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
        ether <private>  txqueuelen 1000  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
        device memory 0xfb100000-fb11ffff  

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1  (Local Loopback)
        RX packets 122  bytes 9620 (9.3 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 122  bytes 9620 (9.3 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

ra0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.1.201  netmask 255.255.255.0  broadcast 192.168.1.255
        inet6 <private>  prefixlen 64  scopeid 0x20<link>
        ether <private>  txqueuelen 1000  (Ethernet)
        RX packets 13575  bytes 5510008 (5.2 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 2892  bytes 724182 (707.2 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
[coinstash@landing ~]$ iwconfig
enp4s0f0  no wireless extensions.

enp4s0f1  no wireless extensions.

ra0       Ralink STA  ESSID:"Optus-4G-E5377-DE79"  Nickname:"MT7601STA"
          Mode:Managed  Frequency=2.437 GHz  Access Point: <private>   
          Bit Rate=65 Mb/s   
          RTS thr:off   Fragment thr:off
          Link Quality=100/100  Signal level:-53 dBm  Noise level:-80 dBm
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

lo        no wireless extensions.

 

0 Kudos
Reply