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--- pfsense:squid:options_which_affect_the_cache [2020/03/30 11:01] – [Memory Cache Size (cache_mem)] peter
+++ pfsense:squid:options_which_affect_the_cache [2020/07/15 09:30] (current) – external edit 127.0.0.1
@@ Line 22: / Line 22: @@
 ----
-===== Low-Water Mark in % =====
+===== Low-Water Mark in % (cache_swap_low) =====
 The low-water mark for AUFS/UFS/diskd cache object eviction by the cache_replacement_policy algorithm.
   * Default: **90**.
 This defines when the replacement should take place.
@@ Line 37: / Line 36: @@
 If utilization is close to the low-water mark less replacement is done each time.
-Defaults are 90% and 95%.  If you have a large cache, 5% could be hundreds of MB.  If this is the case you may wish to set these numbers closer together.
+<WRAP important>
+**WARNING:**  If you have a large cache, 5% could be hundreds of MB. If this is the case you may wish to set this number closer together.
+</WRAP>
 ----
-===== High-Water Mark in % =====
+===== High-Water Mark in % (cache_swap_high) =====
 The high-water mark for AUFS/UFS/diskd cache object eviction by the cache_replacement_policy algorithm.
@@ Line 55: / Line 57: @@
 If utilization is close to the low-water mark less replacement is done each time.
-Defaults are 90% and 95%.  If you have a large cache, 5% could be hundreds of MB.  If this is the case you may wish to set these numbers closer together.
+<WRAP important>
+**WARNING:**  If you have a large cache, 5% could be hundreds of MB.  If this is the case you may wish to set these numbers closer together.
+</WRAP>
 ----
@@ Line 143: / Line 148: @@
-<WRAP info>
-**NOTE:**  This tag does not specify the maximum process size.
+<WRAP important>
+**WARNING:**  This tag does not specify the maximum process size.
 It places a limit on one aspect of squid's memory usage.
@@ Line 151: / Line 158: @@
 Process will probably become twice or three times bigger than the value put here.
+While deciding the RAM space for caching, we should be neither greedy nor paranoid.  If we specify a large percentage of RAM for caching, the overall system performance will suffer as the system will start swapping processes in case there is no free RAM left for other processes.  If we use a very low percentage of RAM for caching, then we’ll not be able to take full advantage of Squid’s caching mechanism.
 </WRAP>