From cdefd8635de24200b55822fa0b6bc23a638fb87a Mon Sep 17 00:00:00 2001 From: David Teigland Date: Mon, 21 Feb 2022 11:35:58 -0600 Subject: [PATCH 33/54] man lvmcache: mention writecache memory usage --- man/lvmcache.7_main | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/man/lvmcache.7_main b/man/lvmcache.7_main index 48cf7b492..73680235b 100644 --- a/man/lvmcache.7_main +++ b/man/lvmcache.7_main @@ -240,6 +240,18 @@ The writecache block size should be chosen to match the xfs sectsz value. It is also possible to specify a sector size of 4096 to mkfs.xfs when creating the file system. In this case the writecache block size of 4096 can be used. +.P +.SS dm-writecache memory usage +.P +The amount of main system memory used by dm-writecache can be a factor +when selecting the writecache cachevol size and the writecache block size. +.P +.IP \[bu] 2 +writecache block size 4096: each 100 GiB of writecache cachevol uses +slighly over 2 GiB of system memory. +.IP \[bu] 2 +writecache block size 512: each 100 GiB of writecache cachevol uses +a little over 16 GiB of system memory. . .SS dm-writecache settings . -- 2.34.3