added troubleshoot stuff plus few format fixes

Author: Marian Zvada

docs/admin/configure-cache-auth.md

@@ -119,9 +119,6 @@ It is very important to keep CRL list updated from cron:
         [root@client ~]$ systemctl daemon-reload
 
 
-### RHEL6
-...to be added
-
 ### Add Authfile for authenticated cache
 Authfile for authenticated cache may differ from `/etc/xrootd/Authfile-noauth` defined in [non-authenticated cache configuration](configure-cache.md). Example:
 ```

docs/admin/configure-cache.md

@@ -113,13 +113,12 @@ In Authfile you want to allow local reads below `$(cachedir)` defined in the mai
 
 ### RHEL7
 On RHEL7 system, you need to run following systemd unit:
+
 * `systemctl start xrootd@stashcache-cache-server.service`
+
 * `systemctl start condor.service`
 
 Please, refer to [start services document](../ops/start.md) for more information.
 
-### RHEL6
-...to be added, old doc for RHEL6 configuration resides temporarily [here](https://twiki.grid.iu.edu/bin/view/Documentation/Release3/InstallStashCache).
-
 When ready with configuration, please [register](../ops/register.md) and [start](../ops/start.md) your StashCache Cache server.
 If you'd like to configure in addition authenticated cache instance, please follow [this](configure-cache-auth.md) document.

docs/ops/troubleshoot.md

@@ -8,9 +8,9 @@ Common settings on the system:
 
 First you need to activate xrootd to create core file when process exits unexpectedly:
 
-* set env variable upon cmsd/xrootd start `DAEMON_COREFILE_LIMIT="unlimited"`
-    RHEL6: env set in `/etc/sysconfig/xrootd`
-    RHEL7: you can use `/etc/sysconfig/xrootd` but prepare override file `/etc/systemd/system/cmsd@clustered.service.d/override.conf` with content:
+* set environment variable upon cmsd/xrootd start `DAEMON_COREFILE_LIMIT="unlimited"`
+  * RHEL6: variable set in `/etc/sysconfig/xrootd` or set as root `ulimit -c unlimited`
+  * RHEL7: you can use `/etc/sysconfig/xrootd` but prepare override file `/etc/systemd/system/cmsd@clustered.service.d/override.conf` with content:
 ```
      [Service]
      EnvironmentFile=-/etc/sysconfig/xrootd
@@ -27,3 +27,6 @@ $ gdb --pid=PID_NR
 ```
 `$ gcore $(pidof xrootd)`
 ```
+
+### Core from not running process:
+* by default, XRootD should leave `core file` in the `/var/spool/xrootd/` when it crashes