On Tue, Aug 06, 2019 at 05:27:54AM -0600, Warren Young wrote: > On Aug 5, 2019, at 6:57 PM, Fred Smith <fre...@fcshome.stoneham.ma.us> wrote: > > > > no core file (yes, ulimit is configured)
yeah, I meant "ulimit -c unlimited" is in effect. I had no idea systemd had made such a drastic change. or is it that someone at RH decided to make it (nearly) impossible to do? I fail to see how it is beneficial to anyone to make it so hard to get core dump files. but thanks for the details! Fred > > That’s nowhere near sufficient. To restore classic core file dumps on CentOS > 7, you must: > > 1. Remove Red Hat’s ABRT system, which wants to catch all of this and handle > it directly. Say something like “sudo yum remove abrt*” > > > 2. Override the default sysctl telling where core dumps land by writing this > file, /etc/sysctl.d/10-core.conf: > > kernel.core_pattern = /tmp/core-%e-%p > kernel.core_uses_pid = 1 > fs.suid_dumpable = 2 > > Then apply those settings with “sudo sysctl —system”. > > I don’t remember what the default is, which this overrides, but I definitely > didn’t want it. > > You can choose any pattern you like, just remember what permissions the > service runs under, because that’s the permission needed by the process that > actually dumps the core to make the file hit the disk. That’s why I chose > /tmp in this example: anyone can write there. > > > 3. Raise the limits by writing the following to > /etc/security/limits.d/10-core.conf: > > * hard core unlimited > * soft core unlimited > > If this is what you meant by “ulimit,” then great, but I suspect you actually > meant “ulimit -c unlimited”, but I believe until you do the above, the ulimit > CLI app can have no effect. You have to log out and back in to make this > take effect. > > Once the above is done, “ulimit -c unlimited” can take effect, but it’s of no > value at all in conjunction with systemd services, for example, since those > don’t run under a standard shell, so your .bash_profile and such aren’t even > exec’d. > > > 4. If your program is launched via systemd, then you must edit > /etc/systemd/system.conf and set > > DefaultLimitCORE=infinity > > then say “sudo systemctl daemon-reeexec” > > Case matters; “Core” won’t work. Ask me how I know. :) > > > 5. If you have a systemd unit file for your service, you have to set a > related value in there as well: > > LimitCore=infinity > > You need both because #4 sets the system-wide cap, while this sets the > per-service value, which can go no higher than the system cap. > > > 6. Restart the service to apply the above two changes. > > > Yes, it really is that difficult to enable classic core dumps on CentOS 7. > You’re welcome. :) > _______________________________________________ > CentOS mailing list > CentOS@centos.org > https://lists.centos.org/mailman/listinfo/centos -- ---- Fred Smith -- fre...@fcshome.stoneham.ma.us ----------------------------- "For him who is able to keep you from falling and to present you before his glorious presence without fault and with great joy--to the only God our Savior be glory, majesty, power and authority, through Jesus Christ our Lord, before all ages, now and forevermore! Amen." ----------------------------- Jude 1:24,25 (niv) ----------------------------- _______________________________________________ CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos
