Discuss March 2020

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63 participants
64 discussions

SSD for Centos SWAP /tmp & /var/ partition
by Keith Roberts 03 Sep '25

03 Sep '25

Has anyone actually used a SSD in a Centos setup? My little experiment with a s/h WD drive for /tmp and SWAP partitions kicked the bucket on Wednesday, when the poor WD drive caught the click-of-death. It was a s/h drive to start with and lasted about 4 months. But that was without the /var/log/ partition being written to it, as I mounted that back onto /var/log from the original drive. So I had to install another (WD) drive, and repartion it and rebuild my RPM package database, from the backed-up Packages file. That seems to be all OK now. I'm wondering if it would be a good idea to use a new SSD for moving all the disk i/o to, that Linux likes to do so often. Plus putting SWAP onto a decent SSD should speed things up somewhat. Here's a short video of a laptop fitted with a SSD drive booting macOS, compared to a similar laptop booting from the standard HDD. The laptop with the SSD boots and loads some apps in 28 seconds. The other one takes twice as long. http://eshop.macsales.com/shop/SSD/OWC/Mercury_Extreme_Pro_6G/?utm_source=t… Kind Regards, Keith Roberts ----------------------------------------------------------------- Websites: http://www.karsites.net http://www.php-debuggers.net http://www.raised-from-the-dead.org.uk All email addresses are challenge-response protected with TMDA [http://tmda.net] -----------------------------------------------------------------

33 96

Issues booting centos7 [dracut is failing to enable centos/root, centos/swap LVs]
by Yannis Milios 01 Feb '25

01 Feb '25

Hello, I'm having a strange problem booting a new centos7 installation. Below some background on this. [I have attached the tech details at the bottom of this message] I started a new CentOS7 installation on a VM, so far all good, o/s boots fine. Then I decided to increase VM disk size (initially was 10G) to 13G. Powered off the VM, increased the vhd via the hypervisor, booted from CentOS livecd, selected "recover my centos installation". Then I used the following sequence of commands to make the new vhd size "visible" to the o/s ... - ran fdisk /dev/sda and deleted partition 2. (This is the LVM partition where the o/s is stored. The first partition is /boot [xfs] partition *non lvm*.) - created a new partition with same starting sector as before deleting it, but a different ending sector (to reflect to the increased space). - set partition type to 8e (lvm), saved settings and exit. - ran pvresize and lvresize to make new space visible to the o/s.All good, I can see the space increase on 'lvdisplay centos/root'. - ran 'mount /dev/mapper/centos-root /mnt/root' to temporarily mount the o/s partition. - ran 'xfs_growfs /mnt/root' to resize the o/s fs to the new size. It was successful and I could actually chroot to the o/s and verify new disk size. - rebooted and tried to boot from hdd this time. Grub menu shows up and loads default kernel (3.10.0-862.9.1.el7.x86_64). - after initial kernel boot up process, booting continues to initrd and then it's where the problem starts... - looks like dracut has issues locating/enabling /dev/mapper/centos-root (lv) and as a result it cannot boot to the 'real' root fs (/). - while in dracut shell, I execute the following command sequence: 1. lvm lvchange -ay /dev/centos/root 2. lvm lvchange -ay /dev/centos/swap 3. ln -s /dev/mapper/centos-root /dev/root 4. exit ...and the o/s boots fine...so looks like the pv,vg,lv is detected properly while in initrd, but somehow dracut has difficulties enabling the root,swap LVs ? - While in o/s, I rebuild initrd by using: 'dracut -f -v -a lvm' Note, I have to use '-a lvm' as for some reason, if don't, the lvm utils (lvm,lvm_scan) are not being included to the initrd, not sure why this happens. After rebooting, same thing happens, I have to manually boot the system via dracut shell. I'm a bit stuck at this point, any clues what I'm doing wrong in here ? As I previously said, this is a new installation, so I could simply reinstall the whole thing, but I would rather try to find out some answer to why is this happening ... :-) [curiosity] Some additional details: ================== I've attached /run/initramfs/rdsosreport.txt file [generated while in inird] here: https://privatebin.net/?fdc4052c0c402884#gdB/QYR3IeR55SxUbjfrkZPQfJ7jMxiUxq… o/s ver=CentOS Linux release 7.5.1804 (Core) [root@localhost ~]# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sda 8:0 0 13G 0 disk ├─sda1 8:1 0 500M 0 part /boot └─sda2 8:2 0 12.5G 0 part ├─centos-root 253:0 0 11.5G 0 lvm / └─centos-swap 253:1 0 1G 0 lvm [SWAP] [root@localhost ~]# cat /etc/default/grub GRUB_TIMEOUT=5 GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)" GRUB_DEFAULT=saved GRUB_DISABLE_SUBMENU=true GRUB_TERMINAL_OUTPUT="console" GRUB_CMDLINE_LINUX="rd.lvm.lv=centos/root rd.lvm.lv=centos/swap rd.shell rhgb" GRUB_DISABLE_RECOVERY="true"

4 11

MATE 1.20 test build for CentOS 7 available
by Greg Bailey 14 Oct '21

14 Oct '21

Hi everyone, There's been discussions in the past about updating MATE RPMs in EPEL-7: https://bugzilla.redhat.com/show_bug.cgi?id=1436260 https://lists.centos.org/pipermail/centos/2019-August/173154.html (and lots of others...) As a proof-of-concept, I've written some scripts that clone specific commits from the Fedora master branches, and then runs a tool to re-apply RPM scriptlets that are required by EL7 but removed from the Fedora .spec files. The scripts are available at: https://github.com/gebailey/mate-rpms/tree/master/1.20/el7 There's also instructions there if you want to try upgrading to MATE 1.20 w/o rebuilding them yourself. If these packages work for others, perhaps we can revisit the idea of updating the epel7 branches of the Fedora git repos and submitting an official update. There's nothing here (yet) about building MATE 1.22 (which might require a newer gcc for EL7), or building anything on CentOS 8, but thought the CentOS 7 users might find this helpful. -Greg

6 17

Brother HL-L2360DW printing quality
by H 23 Jul '20

23 Jul '20

I have the above printer but have not been able to resolve issues with the printing quality in CentOS 7. The test page prints fine but when I print PDF-documents, most recently using Chinese fonts, it is lacking and the pages very hard to read. The settings in the Mate Cups configuration panel are fine and set to 600 dpi, the settings in the printer menu are all OK yet it prints more like maybe 150 or even 75 dpi. Any suggestion what might be wrong?

3 7

bcc tools and bpftrace packages misbuilt?
by Eric Zuck 15 Apr '20

15 Apr '20

After upgrading to 8.1.1911, bcc-tools and bpftrace seem to be broken. Current package versions I have: bpftrace-0.9-3.el8.x86_64 and bcc-tools-0.8.0-4.el8.x86_64 Both of these seem to be pulling in LLVM version 7, rather than the version 8 that is in 8.1.1911: [root@localhost ~]# bpftrace bpftrace: error while loading shared libraries: libclangFrontend.so.7: cannot open shared object file: No such file or directory [root@localhost ~]# /usr/share/bcc/tools/opensnoop Traceback (most recent call last): File "/usr/share/bcc/tools/opensnoop", line 19, in <module> from bcc import ArgString, BPF File "/usr/lib/python3.6/site-packages/bcc/__init__.py", line 27, in <module> from .libbcc import lib, bcc_symbol, bcc_symbol_option, _SYM_CB_TYPE File "/usr/lib/python3.6/site-packages/bcc/libbcc.py", line 17, in <module> lib = ct.CDLL("libbcc.so.0", use_errno=True) File "/usr/lib64/python3.6/ctypes/__init__.py", line 343, in __init__ self._handle = _dlopen(self._name, mode) OSError: libclangFrontend.so.7: cannot open shared object file: No such file or directory Looking through the CentosBug tracker, I see https://bugs.centos.org/view.php?id=16922: qt5-doctools-5.11.1-9.el8 from CentOS CR/8-stream is misbuilt https://bugs.centos.org/view.php?id=16930: rust-1.37.0-1.module_el8.1.0+246+1f1fd47e built against old libLLVM-7.so So, I gather that bcc-tools and bpftrace are not the only packages affected by an LLVM mismatch. Short of downloading and rebuilding the packages, does anyone have any suggestions about workarounds? Regards, -EricZ

1 1

CentOS 8.1 cron does not send mail
by Tobias Kirchhofer 06 Apr '20

06 Apr '20

Hi, we experience difficulties with crond behaviour sending mail since CentOS 8.1. The cron job is the same like we used in CentOS 7. crontab -l /usr/bin/python3 -c 'import random; import time; time.sleep(random.random() * 3600)' && /usr/local/bin/backup.sh backup.sh writes the backup to the remote backup server. There are around 30 machines with the same cron job. The python part spreads the jobs over an hour so that the backup server is not struck at once from about 30 machines. The change in behaviour is that crond sends no mail anymore. It is because of the logical and (&&). Without this crond sends mails. What has changed in CentOS 8 and does anyone has an idea how we could fix it? Thank you! Tobias -- collect(a)shift.agency

5 12

centos 6 vs 7
by Divine Tanyingoh 02 Apr '20

02 Apr '20

Issue: After installing vms on vmware, I noticed a difference in behavior between centos 6 vs 7. On centos 6 I cannot ping the hostname and get a reply without first resolving in the /etc/hosts file by adding a new entry: 192.168.0.47 server1.example.com. But for centos 7 I am able to ping the hostname and get a reply even when I have not made any changes to the /etc/hosts file. Why is there this difference between centos 6 vs 7. Thank you for your assistance.

3 3

Qemu guest(s) in bridge mode cannot see host machine.
by Jerry Geis 31 Mar '20

31 Mar '20

Hi All - I have a Win10 and Centos 8 guest both that bridge mode does not see the host- other computers seem ok. They cannot even ping the host. My host is CentOS 7. I did some searching - I see the issue - but not what was done to resolve it ? Thanks, Jerry

1 0

mlocate-updatedb.timer not working?
by Frank Cox 31 Mar '20

31 Mar '20

I set this computer up with Centos 8 a few days ago. "systemctl status mlocate-updatedb.timer" says "Active (waiting)". But the mlocate database hasn't been updated since the last time I ran updatedb manually. # ls -l /var/lib/mlocate/* -rw-r-----. 1 root slocate 22944208 Feb 29 10:30 /var/lib/mlocate/mlocate.db What have I missed? -- MELVILLE THEATRE ~ Real D 3D Digital Cinema ~ www.melvilletheatre.com

2 2

Problem installing bind-dyndb-ldap
by Michal Zacek 31 Mar '20

31 Mar '20

Hello, is there a way, how to avoid this stupid "module" problem? Google didn't help, except it is quite common at Centos 8.1. [root@centos8 ~]# dnf install bind-dyndb-ldap ..... Running transaction check No available modular metadata for modular package 'bind-dyndb-ldap-11.1-14.module_el8.1.0+253+3b90c921.x86_64', it cannot be installed on the system [root@centos8 ~]# cat /etc/redhat-release CentOS Linux release 8.1.1911 (Core) Thanks, MZa

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Discuss March 2020