<div dir="ltr"><br><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Nov 13, 2017 at 2:27 AM, Robie Basak <span dir="ltr"><<a href="mailto:robie.basak@ubuntu.com" target="_blank">robie.basak@ubuntu.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Hi Mark,<br>
<span class="gmail-"><br>
On Tue, Nov 07, 2017 at 08:11:27PM +0000, Mark Stosberg wrote:<br>
> Some time around the 15.04 release, a policy change was made to quit<br>
> making some logging persistent by default.<br>
<br>
</span>To help me understand the problem, exactly what logging was persistent<br>
previously, and isn't persistent now? Can you please give us an example?<br></blockquote><div><br></div><div>Any data in systemd-journal that is not flush to /var/log/* is gone forever on power fail due</div><div>to the journal being hosted on ephemeral tmpfs (/run/log/journal); </div><div><br></div><div><div># lsb_release -a</div><div>No LSB modules are available.</div><div>Distributor ID:<span style="white-space:pre"> </span>Ubuntu</div><div>Description:<span style="white-space:pre"> </span>Ubuntu 14.04.5 LTS</div><div>Release:<span style="white-space:pre"> </span>14.04</div><div>Codename:<span style="white-space:pre"> </span>trusty</div><div>root@t-nonvocational-azzie:/var/log# ls -al /var/log/</div><div>total 500</div><div>drwxrwxr-x 8 root syslog 4096 Nov 13 15:19 .</div><div>drwxr-xr-x 12 root root 4096 Nov 10 20:43 ..</div><div>drwxr-xr-x 2 root root 4096 Nov 10 20:43 apt</div><div>-rw-r----- 1 syslog adm 2884 Nov 13 15:19 auth.log</div><div>-rw-r--r-- 1 root root 7678 Nov 13 15:12 boot.log</div><div>-rw-rw---- 1 root utmp 0 Nov 10 20:43 btmp</div><div>-rw-r--r-- 1 syslog adm 153678 Nov 13 15:12 cloud-init.log</div><div>-rw-r--r-- 1 root root 3870 Nov 13 15:12 cloud-init-output.log</div><div>drwxr-xr-x 2 root root 4096 Nov 30 2016 dist-upgrade</div><div>-rw-r--r-- 1 root adm 30483 Nov 13 15:12 dmesg</div><div>-rw-r--r-- 1 root root 0 Nov 13 15:12 dmesg.0</div><div>drwxr-xr-x 2 root root 4096 Nov 10 20:41 fsck</div><div>-rw-r----- 1 syslog adm 52797 Nov 13 15:13 kern.log</div><div>drwxr-xr-x 2 landscape root 4096 Nov 13 15:12 landscape</div><div>-rw-rw-r-- 1 root utmp 292292 Nov 13 15:19 lastlog</div><div>-rw-r----- 1 syslog adm 55736 Nov 13 15:17 syslog</div><div>-rw-r--r-- 1 root root 148851 Nov 13 15:12 udev</div><div>drwxr-xr-x 2 root root 4096 May 8 2017 unattended-upgrades</div><div>drwxr-xr-x 2 root root 4096 Nov 13 15:19 upstart</div><div>-rw-rw-r-- 1 root utmp 5376 Nov 13 15:19 wtmp</div></div><div><br></div><div><br></div><div><div>$ lsb_release -a</div><div>No LSB modules are available.</div><div>Distributor ID:<span style="white-space:pre"> </span>Ubuntu</div><div>Description:<span style="white-space:pre"> </span>Ubuntu 16.04.3 LTS</div><div>Release:<span style="white-space:pre"> </span>16.04</div><div>Codename:<span style="white-space:pre"> </span>xenial</div><div>ubuntu@x-undiluvial-edith:/var/log$ ls -al /var/log/</div><div>total 312</div><div>drwxrwxr-x 7 root syslog 4096 Nov 13 15:15 .</div><div>drwxr-xr-x 13 root root 4096 Nov 10 14:25 ..</div><div>drwxr-xr-x 2 root root 4096 Nov 10 14:24 apt</div><div>-rw-r----- 1 syslog adm 3181 Nov 13 15:17 auth.log</div><div>-rw------- 1 root utmp 0 Nov 10 14:24 btmp</div><div>-rw-r--r-- 1 syslog adm 127616 Nov 13 15:15 cloud-init.log</div><div>-rw-r--r-- 1 root root 4271 Nov 13 15:15 cloud-init-output.log</div><div>drwxr-xr-x 2 root root 4096 Oct 20 10:35 dist-upgrade</div><div>drwxr-xr-x 2 root root 4096 Nov 10 14:22 fsck</div><div>-rw-r----- 1 syslog adm 52555 Nov 13 15:15 kern.log</div><div>-rw-rw-r-- 1 root utmp 292292 Nov 13 15:16 lastlog</div><div>drwxr-xr-x 2 root root 4096 Aug 23 02:06 lxd</div><div>-rw-r----- 1 syslog adm 82360 Nov 13 15:17 syslog</div><div>drwxr-x--- 2 root adm 4096 Sep 20 14:13 unattended-upgrades</div><div>-rw-rw-r-- 1 root utmp 2688 Nov 13 15:16 wtmp</div></div><div><br></div><div>boot.log includes services that start on boot, </div><div><br></div><div>These service starts are not part of syslog; ssh for example in boot.log shows</div><div>it starting (but any service may include more information here in case of failure).</div><div><br></div><div><div># grep -i openssh boot.log </div><div> * Starting OpenSSH server [ OK ]</div></div><div><br></div><div><div>$ journalctl -o short-precise --no-pager -u ssh</div><div>-- Logs begin at Mon 2017-11-13 15:15:13 UTC, end at Mon 2017-11-13 15:17:01 UTC. --</div><div>Nov 13 15:15:33.816052 x-undiluvial-edith systemd[1]: Starting OpenBSD Secure Shell server...</div><div>Nov 13 15:15:33.846646 x-undiluvial-edith sshd[1249]: Server listening on 0.0.0.0 port 22.</div><div>Nov 13 15:15:33.847790 x-undiluvial-edith sshd[1249]: Server listening on :: port 22.</div><div>Nov 13 15:15:33.848100 x-undiluvial-edith systemd[1]: Started OpenBSD Secure Shell server.</div><div>Nov 13 15:16:35.015383 x-undiluvial-edith sshd[1317]: Accepted publickey for ubuntu from 10.5.0.10 port 54030 ssh2: RSA SHA256:0cuEJGbgH9aUy12t0jKluNEwLeAF4SIbvimjeM1OLWw</div><div>Nov 13 15:16:35.018911 x-undiluvial-edith sshd[1317]: pam_unix(sshd:session): session opened for user ubuntu by (uid=0)</div></div><div><br></div><div>/var/log/udev is another.</div><div><br></div><div>In general when systems fail to boot, users may not have console access but may retain power control.</div><div>Issuing a shutdown or even hard stop will still preserve data that's been written to the filesystem for later</div><div>inspection. With the bulk if boot and service status and output information included in the journald held in</div><div>tmpfs; we lose that data unless there is some way to flush that data to persistent storage.</div><div><br></div><div>I'm +1 for having journald be persistent by default; it certainly makes debugging boot failures</div><div>much easier since one has actual logs to examine versus nothing at all.</div><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<br>
Thanks,<br>
<br>
Robie<br>
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