ZFS: Difference between revisions

Achooie (talk | contribs)
m →‎boot.zfs.devNodes in virtual machines: this can happen in native NixOS installs as well
Rework encrypted zfs tutorial
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Under manual partitioning [https://nixos.org/manual/nixos/stable/#sec-installation-manual-partitioning] do this instead:
Under manual partitioning [https://nixos.org/manual/nixos/stable/#sec-installation-manual-partitioning] do this instead:


'''Partition your disk with an boot and an zfs partition with your favorite partition tool.'''
'''Partition your disk with your favorite partition tool.'''


Eg. 1G for boot partion, rest for zfs.
We need the following partitions:
 
* 1G for boot partition with "boot" as the partition label (also called name in some tools) and ef00 as partition code
* 10G for a swap partition with "swap" as the partition label and 8200 as partition code
* The rest of disk space for zfs with "root" as the partition label and 8300 as partition code (default code)
 
Reason for swap partition: ZFS does use a caching mechanism that is different from the normal Linux cache infrastructure.
In low-memory situations, ZFS therefore might need a bit longer to free up memory from its cache. The swap partition will help with that.


Example output from fdisk:
Example output from fdisk:


<syntaxhighlight lang="bash">
<syntaxhighlight lang="bash">
sudo gdisk /dev/nvme0n1
GPT fdisk (gdisk) version 1.0.9.1
...
Command (? for help): p
Disk /dev/nvme0n1: 500118192 sectors, 238.5 GiB
Sector size (logical/physical): 512/512 bytes
Disk identifier (GUID): CA926E8C-47F6-416A-AD1A-C2190CF5D1F8
Partition table holds up to 128 entries
Main partition table begins at sector 2 and ends at sector 33
First usable sector is 34, last usable sector is 500118158
Partitions will be aligned on 2048-sector boundaries
Total free space is 2669 sectors (1.3 MiB)


fdisk /dev/nvme0n1
Number  Start (sector)    End (sector) Size      Code  Name
Command (m for help): p
  1            2048        2099199  1024.0 MiB  EF00  boot
  2        2099200        23070719  10.0 GiB    8200  swap
  3        23070720      500117503  227.5 GiB  8300  root


Disk /dev/nvme0n1: 931.51 GiB, 1000204886016 bytes, 1953525168 sectors
Command (? for help):  
...
Device          Start        End    Sectors  Size Type
/dev/nvme0n1p1    2048    2099199    2097152    1G EFI System
/dev/nvme0n1p2 2099200 1953523711 1951424512 930.5G Linux filesystem
</syntaxhighlight>
</syntaxhighlight>
'''Note:''' Remember to set boot partition (first partition) to "EFI System" type


'''Make zfs pool with encryption and mount points:'''
'''Make zfs pool with encryption and mount points:'''
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zpool create -O encryption=on -O keyformat=passphrase -O keylocation=prompt -O compression=on -O mountpoint=none -O xattr=sa -O acltype=posixacl -o ashift=12 zpool /dev/nvme0n1p2
zpool create -O encryption=on -O keyformat=passphrase -O keylocation=prompt -O compression=on -O mountpoint=none -O xattr=sa -O acltype=posixacl -o ashift=12 zpool /dev/nvme0n1p2


zfs create -o mountpoint=legacy zpool/root
zfs create zpool/root
zfs create -o mountpoint=legacy zpool/nix
zfs create zpool/nix
zfs create -o mountpoint=legacy zpool/var
zfs create zpool/var
zfs create -o mountpoint=legacy zpool/home
zfs create zpool/home


mkdir /mnt/root
mkdir /mnt/root
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mkdir /mnt/nix /mnt/var /mnt/home
mkdir /mnt/nix /mnt/var /mnt/home


mount -t zfs zpool/nix /mnt/nix
mount -t zfs zpool/nix /mnt/nix -o zfsutil
mount -t zfs zpool/var /mnt/var
mount -t zfs zpool/var /mnt/var -o zfsutil
mount -t zfs zpool/home /mnt/home
mount -t zfs zpool/home /mnt/home -o zfsutil
</syntaxhighlight>
</syntaxhighlight>


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mkfs.fat -F 32 -n boot /dev/nvme0n1p1
mkfs.fat -F 32 -n boot /dev/nvme0n1p1
</syntaxhighlight>
</syntaxhighlight>


'''Installation:'''
'''Installation:'''
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   };
   };


   fileSystems."/" =
   # for local disks that are not shared over the network, we don't need this to be random
    { device = "zpool/root";
  networking.hostId = "8425e349";
      fsType = "zfs";
    };


   fileSystems."/nix" =
   fileSystems."/" = {
     { device = "zpool/nix";
     device = "zpool/root";
      fsType = "zfs";
    fsType = "zfs";
     };
     options = [ "zfsutil" ];
  };


   fileSystems."/var" =
   fileSystems."/nix" = {
     { device = "zpool/var";
     device = "zpool/nix";
      fsType = "zfs";
    fsType = "zfs";
     };
     options = [ "zfsutil" ];
  };


   fileSystems."/home" =
   fileSystems."/var" = {
     { device = "zpool/home";
     device = "zpool/var";
      fsType = "zfs";
    fsType = "zfs";
     };
     options = [ "zfsutil" ];
  };


   fileSystems."/boot" =
   fileSystems."/home" = {
     { device = "/dev/disk/by-uuid/2A11-F4EF";
    device = "zpool/home";
      fsType = "vfat";
    fsType = "zfs";
    };
     options = [ "zfsutil" ];
  };
 
  fileSystems."/boot" = {  
  device = "/dev/disk/by-partlabel/boot";
  fsType = "vfat";
  options = [ "zfsutil" ];
  };


   swapDevices = [ ];
   swapDevices = [{
    device = "/dev/disk/by-partlabel/swap";
    randomEncryption = true;
  }];
}
}
</syntaxhighlight>
</syntaxhighlight>