manager 4.3: limit cache dir size to about 60% of free space (#3700)

* SUSE/spacewalk#26396
* #3693

* Update modules/specialized-guides/pages/large-deployments/tuning.adoc
* Apply suggestions from code review

.changelog

@@ -4,8 +4,10 @@
 # - Fixed error in Bat section of Upgrade Guide (bsc#1234567)
 # For guidelines: https://en.opensuse.org/openSUSE:Creating_a_changes_file_(RPM)#Changelog_section_.28.25changelog.29
 
-- Corrected server SSL self-signed certificates renewal procedure in Administration
-  Guide (bsc#1235696)
+- Added note to limit Squid's cache_dir size to 60% of available
+  free space in Installation and Upgrade Guide
+- Corrected server SSL self-signed certificates renewal procedure in
+  Administration Guide (bsc#1235696)
 - Clarify functionality of CLM package/patch allow filters
   (bsc#1236234)
 - Improved documentation on CLM filters in Administration Guide

modules/installation-and-upgrade/pages/hardware-requirements.adoc

@@ -140,6 +140,7 @@ For more information about managing a large number of clients, see xref:speciali
 ====
 
 
+[[proxy-hardware-requirements]]
 == Proxy Hardware Requirements
 
 [cols="1,1,1", options="header"]
@@ -188,6 +189,15 @@ As a result of this behavior:
     For a guide to size estimation, see the <<server-hardware-requirements>> section.
 
 
+[NOTE]
+====
+In general, {suse} recommends to adjust the value for the cache directory to about 60 % of available free space.
+Users can set the [option]``cache_dir`` option in the [path]``squid.conf`` manually.
+
+For more information, see xref:specialized-guides:large-deployments/tuning.adoc#tune_proxy[].
+====
+
+
 
 [[install-hardware-requirements-storage]]
 == Storage Devices and Permissions

modules/specialized-guides/pages/large-deployments/tuning.adoc

@@ -741,3 +741,29 @@ pidstat -p ALL -r --human 1 60 | tee pidstat-memory.log
 ----
 
 This command will save a copy of displayed data in the `pidstat-memory.log` file for later analysis.
+
+
+[[tune_proxy]]
+== Proxy
+
+[[cache_dir]]
+=== `cache_dir`
+
+[cols="1,1"]
+|===
+| Description          | The amount of storage space for the squid cache directory.
+| Tune when            | More than the default storage space is required.
+| Value default        | 100
+| Value recommendation | 60 % of available free space
+| Location             | [path]``/etc/squid/squid.conf``
+| Example              | cache_dir aufs /var/cache/squid 15000 16 256
+| After changing       | 
+| More information     | [path]``/etc/squid/squid.conf.documented''
+|===
+
+
+[NOTE]
+====
+In general, {suse} recommends to adjust the value for the cache directory to about 60 % of available free space.
+Users can set the [option]``cache_dir`` option in the [path]``squid.conf`` manually.
+====