Discuss August 2017

discuss@lists.centos.org

94 participants
72 discussions

Re: [CentOS] BUG: soft lockup - CPU#0 stuck for 36s! [swapper/0:0]
by KM 25 Apr '18

25 Apr '18

All,This happens on all of our CentOS 7 VMs. but as stated in the email trail, the file softlockup_thresh does not exist. Should it be added? What is the best way to get rid of this behavior. Thanks in advance and sorry if I missed something along the way.KM From: correomm <correomm(a)gmail.com> To: CentOS mailing list <centos(a)centos.org> Sent: Thursday, August 18, 2016 1:55 PM Subject: Re: [CentOS] BUG: soft lockup - CPU#0 stuck for 36s! [swapper/0:0] Yes, I tried it, but does not exists: vmguest # cat /proc/sys/kernel/softlockup_thresh cat: /proc/sys/kernel/softlockup_thresh: No such file or directory On Thu, Aug 18, 2016 at 2:06 PM, Carlos A. Carnero Delgado < carloscarnero(a)gmail.com> wrote: > 2016-08-18 12:39 GMT-04:00 correomm <correomm(a)gmail.com>: > > > This bug is reported only on the VM's with CentOS 7 running on on VMware > > ESXi 5.1. > > The vSphere performance graph shows high CPU consume and disk activity > only > > on VM's with CentOS 7. Sometimes I can not connect remotely with ssh > > (timeout error). > > > > I'm also seeing those errors in several servers, running under 5.5. > Currently investigating if this > <https://kb.vmware.com/selfservice/microsites/search. > do?language=en_US&cmd=displayKC&externalId=1009996> > has anything to do (the resource overcommit bit). > > HTH, > Carlos. > _______________________________________________ > CentOS mailing list > CentOS(a)centos.org > https://lists.centos.org/mailman/listinfo/centos > _______________________________________________ CentOS mailing list CentOS(a)centos.org https://lists.centos.org/mailman/listinfo/centos | | Virus-free. www.avg.com |

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kmod-jfs on Centos 6
by H 27 Oct '17

27 Oct '17

I am a bit of a noob with Linux and Centos but would like to be able to access an old external USB disk formatted JFS by OS/2. I have seen there is a kmod-jfs package on elrepo that ought to work with Centos 6 but am unsure how to install kmods without hosing my existing system... If anyone would like to be so kind to give me a short how-to, I would be very grateful. Thank you.

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NFS mount on Centos 7 crashing
by Nikolaos Milas 20 Oct '17

20 Oct '17

Hello, We have a VM (under KVM - a VPS service by our ISP) running CentOS 7. On it we have 2 NFS mounts, one for backup and one as a live file system (where there are two user homes as well): ----------------------------------------------------------------------------------------------------------------------- # cat /etc/fstab /dev/mapper/centos-root / xfs defaults 0 0 UUID=7a3ae70a-8ef3-463b-8f5b-be4e2e7be894 /boot xfs defaults 0 0 /dev/mapper/centos-swap swap swap defaults 0 0 10.201.40.34:/data/col1/noc-bkups-1 /mnt/dd2500-1 nfs auto,noatime,nolock,bg,nfsvers=3,intr,tcp,actimeo=1800 0 0 10.201.40.34:/data/col1/hesperia-mount /hesperiamount nfs auto,noatime,nolock,bg,nfsvers=3,intr,tcp,actimeo=1800 0 0 ----------------------------------------------------------------------------------------------------------------------- This setup has been working fine for over a year, even under significant load, without issues. However, yesterday, the "live" NFS mount (/hesperiamount) has started crashing. When bootingeverything is fine, but very soonafter boot we noticed that we lose communication to the mount, although the remote storage system is accessible(without reporting any errors) and no network issues have occurred. We found that dmesg reports failures with call traces (2 examples): https://pastebin.com/GVSDbxFr https://pastebin.com/WujKQuHG This happens repeatedly/consistently (after several reboots) so we have been forced to replace the NFS mount with a local mount (on a new local virtual hard disk), to restore normal system operation. So the fstab has now become: ------------------------------------------------------------------------------------------------------------------- # cat /etc/fstab /dev/mapper/centos-root / xfs defaults 0 0 UUID=7a3ae70a-8ef3-463b-8f5b-be4e2e7be894 /boot xfs defaults 0 0 /dev/mapper/centos-swap swap swap defaults 0 0 /dev/mapper/vg2-lv1 /hesperiamount xfs defaults 0 0 10.201.40.34:/data/col1/noc-bkups-1 /mnt/dd2500-1 nfs auto,noatime,nolock,bg,nfsvers=3,intr,tcp,actimeo=1800 0 0 # 10.201.40.34:/data/col1/hesperia-mount /hesperiamount nfs auto,noatime,nolock,bg,nfsvers=3,intr,tcp,actimeo=1800 0 0 ------------------------------------------------------------------------------------------------------------------- Note that when I later mounted manually the same NFS share on the same box (in order to copy data from it using rsync), it did not crash (but it only had reads and no writes in this scenario). The share was manually mounted with the following command: # mount -vv -o auto,noatime,nolock,bg,nfsvers=3,intr,tcp,actimeo=1800 -t nfs 10.201.40.34:/data/col1/hesperia-mount /hesperiamount2 Questions: * Is this a known issue/bug? * Have we possibly made any NFS misconfigurations (which however have not caused any errors for about a year now)? * What could we do to prevent the error from occurring again? Please advise. Thanks, Nick

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Update of cloud-init in CentOS 7 Extras
by Pierre Riteau 14 Sep '17

14 Sep '17

Hello, The version of cloud-init packaged in CentOS 7 Extras is rather old (0.7.5, which was released in 2014). It is missing some functionality that we would like to use, as well as important bug fixes. Before I tackle rebuilding the package myself, I would like to know if there is a plan to update extras to a newer cloud-init version, or if has anyone has already updated cloud-init and would be happy to share the spec? Many thanks, Pierre Riteau Chameleon Lead DevOps Engineer

2 4

system slowdown
by Larry Martell 13 Sep '17

13 Sep '17

I have a CentOS 6 system that has suddenly starting significantly slowing down. It runs a django app with an Apache server and MySQL server. There is plenty of disk space and no process seems to be hogging the memory or CPU. But operations that used to take 5 minutes are now taking hours and hours. Coinciding with this slow down I see these messages in /var/log/messages (this is hand typed, as I can't copy/paste or send email from this system, although for a change I do have remote access via 2 VPN hops): kernel: BUG: soft lockup - CPU#5 stuck for 67s! [khungtaskd] kernel: BUG: soft lockup - CPU#7 stuck for 67s! [khugepaged] These messages started appearing today around 7 AM, which is when users started reporting the slowdown. They are still occurring periodically and the system is still slow. Are these messages caused by the slowdown or are they the reason for it? Are they useful in tracking down the problem?

2 3

Simple OCSP server ??
by Alice Wonder 05 Sep '17

05 Sep '17

Hello list, I'm contemplating running my own CA to implement the new proposed ISP for validation of S/MIME certificates via DANE. I already use self-signed for my MX servers (with 3 1 1 dane records on TCP port 25) but I don't want to use self-signed for S/MIME for user specific x.509 certs because A) That's potentially a lot of DNS records B) That requires a hash of the e-mail addresses in DNS Instead, I will be using a wildcard in DNS with an intermediary that signs the user x.509 certificates. Using an intermediary to sign their certificates though means I can't just revoke their certificates by removing the DNS certificate, I'll need to provide an OCSP server for when one of their private keys gets compromised. I found https://access.redhat.com/documentation/en-US/Red_Hat_Certificate_System/8.… but it looks like that is intended for enterprise, more complex than I need. Anyone know of a good simple script for providing OCSP ?? -=- Not relevant to question but just important for me to note, I will *not* be asking people to install my root certificate in their e-mail clients. I think it is a bad practice to get users in the habit of installing root certificates. I think the PKI system has way way way to many root certificates as it is. I want a world where DANE validates most certificates, and only a few root certificates are needed for things like banks where EV certificates are a must. DANE as a way to validate S/MIME I think will be a godsend to e-mail security, I hope clients implement it.

2 5

Problem with IPTABLES logging message to the screen/console
by Jobst Schmalenbach 05 Sep '17

05 Sep '17

Hi I am not sure how to solve this. I am constantly getting messages that should go into the kern/message log printed on screen - MOSTLY from iptables. The messages are ALSO logged to the syslog files. It still prints those message onto the console screen even if I am logged off (security issue). When logged in on the console its anoying as I constantly have to hit CTRL-L to refresh the screen to get rid of those messages. However it does NOT happen when I ssh into the machine. How can I solve this that those messages are NOT printed. thanks Jobst -- Share your knowledge. It's a way to achieve immortality. | |0| | Jobst Schmalenbach, jobst(a)barrett.com.au, General Manager | | |0| |0|0|0| +61 3 9532 7677, POBox 277, Caulfield South, 3162, Australia

2 2

rkhunter and prelink
by m.roth＠5-cent.us 02 Sep '17

02 Sep '17

Can't remember if I posted this before... We're getting warnings from rkhunterWarning: Checking for prerequisites [ Warning ] All file hash checks will be skipped because: This system uses prelinking, but the hash function command does not look like SHA1 or MD5. Now, googling, I find people saying to rm /etc/prelink.cache, then run rkhunter --propupd. Works. And then, prelink runs in the middle of the night, via /etc/cron.daily, and when the cron job of rkhunter runs, it's back to complaining. Anyone have any ideas what's going on here? I don't see anything in the prelink.conf, or any options in the prelink manpage to tell is what hash to use. mark

5 7

spice client?
by hw 01 Sep '17

01 Sep '17

Hi, how do I connect to a VM running on a removte machine with some sort of spice client? There doesn´t seem to be any spice client available in Centos 7 that works.

3 7

Syncronize systemctl status with reality?
by Leroy Tennison 30 Aug '17

30 Aug '17

The particular issue is with puppetmaster (which admittedly takes 4 minutes to actually start, setting TimeoutStartSec=300 in it's unit file stopped the false timeout report) but I have seen it one other time (don't remember the details). systemctl status puppetmaster ● puppetmaster.service - Puppet master Loaded: loaded (/lib/systemd/system/puppetmaster.service; enabled; vendor preset: enabled) Active: failed (Result: resources) since Tue 2017-08-29 11:24:36 CDT; 22min ago Process: 897 ExecStart=/usr/bin/puppet master (code=exited, status=0/SUCCESS) Aug 29 11:22:39 puppetmaster02 systemd[1]: Starting Puppet master... Aug 29 11:24:36 puppetmaster02 puppet-master[1233]: Reopening log files Aug 29 11:24:36 puppetmaster02 puppet-master[1233]: Starting Puppet master version 3.8.5 Aug 29 11:24:36 puppetmaster02 puppet-master[1233]: Could not run: Address already in use - listen(2) Aug 29 11:24:36 puppetmaster02 systemd[1]: puppetmaster.service: PID 1233 read from file /run/puppet/master.pid does not exist or is a zombie. Aug 29 11:24:36 puppetmaster02 systemd[1]: Failed to start Puppet master. Aug 29 11:24:36 puppetmaster02 systemd[1]: puppetmaster.service: Unit entered failed state. Aug 29 11:24:36 puppetmaster02 systemd[1]: puppetmaster.service: Failed with result 'resources'. However, ps -ef | grep puppet (run just after the above) returns puppet 1380 1 0 11:26 ? 00:00:08 Passenger RubyApp: /usr/share/puppet/rack/puppetmasterd root 2015 1341 0 11:48 pts/0 00:00:00 grep --color=auto puppet Earlier ps .. also reported puppet 1355 1166 3 11:26 ? 00:00:01 Passenger AppPreloader: /usr/share/puppet/rack/puppetmasterd And, the "bottom line", puppet agent -t on a client works. It reports finishing the catalog run and the client's yaml files on puppetmaster are up to date. Is there a command to tell systemd to re-scan running state and update its understanding on what it finds? I tried systemctl daemon-reload just to be sure that didn't solve the problem before posting this.

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Discuss August 2017