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linux:fs:zfs:tuning [2026/03/20 07:20] – niziaklinux:fs:zfs:tuning [2026/03/20 07:51] (current) – niziak
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 # apt install zfsutils-linux # apt install zfsutils-linux
  
-# arcstat+# zarcstat
     time  read  miss  miss%  dmis  dm%  pmis  pm%  mmis  mm%  size     c  avail     time  read  miss  miss%  dmis  dm%  pmis  pm%  mmis  mm%  size     c  avail
 16:47:26     3     0      0     0    0     0    0     0    0   15G   15G   1.8G 16:47:26     3     0      0     0    0     0    0     0    0   15G   15G   1.8G
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 </code> </code>
  
 <code bash> <code bash>
-# arc_summary+# zarcsummary -s arc
  
 ARC size (current):                                    98.9 %   15.5 GiB ARC size (current):                                    98.9 %   15.5 GiB
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         Dnode cache size (hard limit):                 10.0 %    1.2 GiB         Dnode cache size (hard limit):                 10.0 %    1.2 GiB
         Dnode cache size (current):                     5.3 %   63.7 MiB         Dnode cache size (current):                     5.3 %   63.7 MiB
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 </code> </code>
  
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   * ''zfs_arc_max'': Maximum size of ARC in bytes. If set to 0 then the maximum size of ARC is determined by the amount of system memory installed (50% on Linux)   * ''zfs_arc_max'': Maximum size of ARC in bytes. If set to 0 then the maximum size of ARC is determined by the amount of system memory installed (50% on Linux)
   * ''zfs_arc_min'': Minimum ARC size limit. When the ARC is asked to shrink, it will stop shrinking at ''c_min''  as tuned by ''zfs_arc_min''.   * ''zfs_arc_min'': Minimum ARC size limit. When the ARC is asked to shrink, it will stop shrinking at ''c_min''  as tuned by ''zfs_arc_min''.
-  * ''zfs_arc_meta_limit_percent'': Sets the limit to ARC metadata, arc_meta_limit, as a percentage of the maximum size target of the ARC, ''c_max''. Default is 75.+  * ''zfs_arc_meta_balance'': Balance between metadata and data on ghost hits. Values above 100 increase metadata caching by proportionally reducing effect of ghost data hits on target data/metadata rate. [[https://openzfs.github.io/openzfs-docs/man/master/4/zfs.4.html#zfs_arc_meta_balance]] 
 Proxmox recommends following [[https://pve.proxmox.com/wiki/ZFS_on_Linux#sysadmin_zfs_limit_memory_usage|rule]]: Proxmox recommends following [[https://pve.proxmox.com/wiki/ZFS_on_Linux#sysadmin_zfs_limit_memory_usage|rule]]:
 <code> <code>
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 echo "$[4 * 1024*1024*1024]" >/sys/module/zfs/parameters/zfs_arc_max echo "$[4 * 1024*1024*1024]" >/sys/module/zfs/parameters/zfs_arc_max
 echo "$[128     *1024*1024]" >/sys/module/zfs/parameters/zfs_arc_min echo "$[128     *1024*1024]" >/sys/module/zfs/parameters/zfs_arc_min
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 </code> </code>
  
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 options zfs zfs_arc_min=134217728 options zfs zfs_arc_min=134217728
 options zfs zfs_arc_meta_limit_percent=75 options zfs zfs_arc_meta_limit_percent=75
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 </code> </code>