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vm:proxmox:kvm:linux [2026/07/07 16:41] – niziakvm:proxmox:kvm:linux [2026/07/08 20:55] (current) – niziak
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 ====== Linux Guests ====== ====== Linux Guests ======
 +
 +Enable WriteBack to group small writes into batches.
  
 ===== Filesystem ===== ===== Filesystem =====
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   * BTRFS with single copy of meta, system and data   * BTRFS with single copy of meta, system and data
 +  * metada chunk is 16kb (''--nodesize 16k'') so ''volblock'' size should be >=16kb
   * I/O is better on modern guest Kernel 6.1 (vs 5.10)   * I/O is better on modern guest Kernel 6.1 (vs 5.10)
   * I/O is better whem VM storage is "no cache"   * I/O is better whem VM storage is "no cache"
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 So it is best to fit guest block sizes into ZFS block (16k) sizes: So it is best to fit guest block sizes into ZFS block (16k) sizes:
- +  * btrfs: 
-  * mkfs.btrfs options: ''--nodesize 16k'' +    * mkfs.btrfs options: ''--nodesize 16k'' 
-  * btrfs mount options: ''-o noatime'' +    * btrfs mount options: ''-o noatime'' 
-  * mkfs.ext4 options: ''-b 4096 -E stride=4,stripe-width=8'' +  * ext4: 
-  * ext4 mount options: ''-o noatime,user_xattr''+    * mkfs.ext4 options: 
 +      * volblocksize=16kB ''-b 4096 -E stride=4,stripe-width=8 -O mmp'' 
 +      * volblocksize=64kB ''-b 4096 -E stride=16,stripe-width=16 -O mmp'' 
 +      * volblocksize=128kB ''-b 4096 -E stride=32,stripe-width=32 -O mmp'' 
 +    * ext4 mount options: ''-o discard,noatime,nodiratime,lazytime,user_xattr'' 
 +  * xfs: 
 +    * mkfs.xfs options: '''' 
 +    * xfs mount options: ''-o noatime,logbiaszie=256k''