diff options
Diffstat (limited to 'nixpkgs/nixos/modules/tasks/filesystems/zfs.nix')
| -rw-r--r-- | nixpkgs/nixos/modules/tasks/filesystems/zfs.nix | 546 |
1 files changed, 546 insertions, 0 deletions
diff --git a/nixpkgs/nixos/modules/tasks/filesystems/zfs.nix b/nixpkgs/nixos/modules/tasks/filesystems/zfs.nix new file mode 100644 index 000000000000..37a19fb9fc8c --- /dev/null +++ b/nixpkgs/nixos/modules/tasks/filesystems/zfs.nix @@ -0,0 +1,546 @@ +{ config, lib, pkgs, utils, ... }: +# +# todo: +# - crontab for scrubs, etc +# - zfs tunables + +with utils; +with lib; + +let + + cfgZfs = config.boot.zfs; + cfgSnapshots = config.services.zfs.autoSnapshot; + cfgSnapFlags = cfgSnapshots.flags; + cfgScrub = config.services.zfs.autoScrub; + + inInitrd = any (fs: fs == "zfs") config.boot.initrd.supportedFilesystems; + inSystem = any (fs: fs == "zfs") config.boot.supportedFilesystems; + + enableAutoSnapshots = cfgSnapshots.enable; + enableAutoScrub = cfgScrub.enable; + enableZfs = inInitrd || inSystem || enableAutoSnapshots || enableAutoScrub; + + kernel = config.boot.kernelPackages; + + packages = if config.boot.zfs.enableUnstable then { + spl = null; + zfs = kernel.zfsUnstable; + zfsUser = pkgs.zfsUnstable; + } else { + spl = kernel.spl; + zfs = kernel.zfs; + zfsUser = pkgs.zfs; + }; + + autosnapPkg = pkgs.zfstools.override { + zfs = packages.zfsUser; + }; + + zfsAutoSnap = "${autosnapPkg}/bin/zfs-auto-snapshot"; + + datasetToPool = x: elemAt (splitString "/" x) 0; + + fsToPool = fs: datasetToPool fs.device; + + zfsFilesystems = filter (x: x.fsType == "zfs") config.system.build.fileSystems; + + allPools = unique ((map fsToPool zfsFilesystems) ++ cfgZfs.extraPools); + + rootPools = unique (map fsToPool (filter fsNeededForBoot zfsFilesystems)); + + dataPools = unique (filter (pool: !(elem pool rootPools)) allPools); + + snapshotNames = [ "frequent" "hourly" "daily" "weekly" "monthly" ]; + + # When importing ZFS pools, there's one difficulty: These scripts may run + # before the backing devices (physical HDDs, etc.) of the pool have been + # scanned and initialized. + # + # An attempted import with all devices missing will just fail, and can be + # retried, but an import where e.g. two out of three disks in a three-way + # mirror are missing, will succeed. This is a problem: When the missing disks + # are later discovered, they won't be automatically set online, rendering the + # pool redundancy-less (and far slower) until such time as the system reboots. + # + # The solution is the below. poolReady checks the status of an un-imported + # pool, to see if *every* device is available -- in which case the pool will be + # in state ONLINE, as opposed to DEGRADED, FAULTED or MISSING. + # + # The import scripts then loop over this, waiting until the pool is ready or a + # sufficient amount of time has passed that we can assume it won't be. In the + # latter case it makes one last attempt at importing, allowing the system to + # (eventually) boot even with a degraded pool. + importLib = {zpoolCmd, awkCmd, cfgZfs}: '' + poolReady() { + pool="$1" + state="$("${zpoolCmd}" import 2>/dev/null | "${awkCmd}" "/pool: $pool/ { found = 1 }; /state:/ { if (found == 1) { print \$2; exit } }; END { if (found == 0) { print \"MISSING\" } }")" + if [[ "$state" = "ONLINE" ]]; then + return 0 + else + echo "Pool $pool in state $state, waiting" + return 1 + fi + } + poolImported() { + pool="$1" + "${zpoolCmd}" list "$pool" >/dev/null 2>/dev/null + } + poolImport() { + pool="$1" + "${zpoolCmd}" import -d "${cfgZfs.devNodes}" -N $ZFS_FORCE "$pool" + } + ''; + +in + +{ + + ###### interface + + options = { + boot.zfs = { + enableUnstable = mkOption { + type = types.bool; + default = false; + description = '' + Use the unstable zfs package. This might be an option, if the latest + kernel is not yet supported by a published release of ZFS. Enabling + this option will install a development version of ZFS on Linux. The + version will have already passed an extensive test suite, but it is + more likely to hit an undiscovered bug compared to running a released + version of ZFS on Linux. + ''; + }; + + extraPools = mkOption { + type = types.listOf types.str; + default = []; + example = [ "tank" "data" ]; + description = '' + Name or GUID of extra ZFS pools that you wish to import during boot. + + Usually this is not necessary. Instead, you should set the mountpoint property + of ZFS filesystems to <literal>legacy</literal> and add the ZFS filesystems to + NixOS's <option>fileSystems</option> option, which makes NixOS automatically + import the associated pool. + + However, in some cases (e.g. if you have many filesystems) it may be preferable + to exclusively use ZFS commands to manage filesystems. If so, since NixOS/systemd + will not be managing those filesystems, you will need to specify the ZFS pool here + so that NixOS automatically imports it on every boot. + ''; + }; + + devNodes = mkOption { + type = types.path; + default = "/dev/disk/by-id"; + example = "/dev/disk/by-id"; + description = '' + Name of directory from which to import ZFS devices. + + This should be a path under /dev containing stable names for all devices needed, as + import may fail if device nodes are renamed concurrently with a device failing. + ''; + }; + + forceImportRoot = mkOption { + type = types.bool; + default = true; + description = '' + Forcibly import the ZFS root pool(s) during early boot. + + This is enabled by default for backwards compatibility purposes, but it is highly + recommended to disable this option, as it bypasses some of the safeguards ZFS uses + to protect your ZFS pools. + + If you set this option to <literal>false</literal> and NixOS subsequently fails to + boot because it cannot import the root pool, you should boot with the + <literal>zfs_force=1</literal> option as a kernel parameter (e.g. by manually + editing the kernel params in grub during boot). You should only need to do this + once. + ''; + }; + + forceImportAll = mkOption { + type = types.bool; + default = true; + description = '' + Forcibly import all ZFS pool(s). + + This is enabled by default for backwards compatibility purposes, but it is highly + recommended to disable this option, as it bypasses some of the safeguards ZFS uses + to protect your ZFS pools. + + If you set this option to <literal>false</literal> and NixOS subsequently fails to + import your non-root ZFS pool(s), you should manually import each pool with + "zpool import -f <pool-name>", and then reboot. You should only need to do + this once. + ''; + }; + + requestEncryptionCredentials = mkOption { + type = types.bool; + default = config.boot.zfs.enableUnstable; + description = '' + Request encryption keys or passwords for all encrypted datasets on import. + Dataset encryption is only supported in zfsUnstable at the moment. + For root pools the encryption key can be supplied via both an + interactive prompt (keylocation=prompt) and from a file + (keylocation=file://). Note that for data pools the encryption key can + be only loaded from a file and not via interactive prompt since the + import is processed in a background systemd service. + ''; + }; + + }; + + services.zfs.autoSnapshot = { + enable = mkOption { + default = false; + type = types.bool; + description = '' + Enable the (OpenSolaris-compatible) ZFS auto-snapshotting service. + Note that you must set the <literal>com.sun:auto-snapshot</literal> + property to <literal>true</literal> on all datasets which you wish + to auto-snapshot. + + You can override a child dataset to use, or not use auto-snapshotting + by setting its flag with the given interval: + <literal>zfs set com.sun:auto-snapshot:weekly=false DATASET</literal> + ''; + }; + + flags = mkOption { + default = "-k -p"; + example = "-k -p --utc"; + type = types.str; + description = '' + Flags to pass to the zfs-auto-snapshot command. + + Run <literal>zfs-auto-snapshot</literal> (without any arguments) to + see available flags. + + If it's not too inconvenient for snapshots to have timestamps in UTC, + it is suggested that you append <literal>--utc</literal> to the list + of default options (see example). + + Otherwise, snapshot names can cause name conflicts or apparent time + reversals due to daylight savings, timezone or other date/time changes. + ''; + }; + + frequent = mkOption { + default = 4; + type = types.int; + description = '' + Number of frequent (15-minute) auto-snapshots that you wish to keep. + ''; + }; + + hourly = mkOption { + default = 24; + type = types.int; + description = '' + Number of hourly auto-snapshots that you wish to keep. + ''; + }; + + daily = mkOption { + default = 7; + type = types.int; + description = '' + Number of daily auto-snapshots that you wish to keep. + ''; + }; + + weekly = mkOption { + default = 4; + type = types.int; + description = '' + Number of weekly auto-snapshots that you wish to keep. + ''; + }; + + monthly = mkOption { + default = 12; + type = types.int; + description = '' + Number of monthly auto-snapshots that you wish to keep. + ''; + }; + }; + + services.zfs.autoScrub = { + enable = mkOption { + default = false; + type = types.bool; + description = '' + Enables periodic scrubbing of ZFS pools. + ''; + }; + + interval = mkOption { + default = "Sun, 02:00"; + type = types.str; + example = "daily"; + description = '' + Systemd calendar expression when to scrub ZFS pools. See + <citerefentry><refentrytitle>systemd.time</refentrytitle> + <manvolnum>7</manvolnum></citerefentry>. + ''; + }; + + pools = mkOption { + default = []; + type = types.listOf types.str; + example = [ "tank" ]; + description = '' + List of ZFS pools to periodically scrub. If empty, all pools + will be scrubbed. + ''; + }; + }; + }; + + ###### implementation + + config = mkMerge [ + (mkIf enableZfs { + assertions = [ + { + assertion = config.networking.hostId != null; + message = "ZFS requires networking.hostId to be set"; + } + { + assertion = !cfgZfs.forceImportAll || cfgZfs.forceImportRoot; + message = "If you enable boot.zfs.forceImportAll, you must also enable boot.zfs.forceImportRoot"; + } + { + assertion = cfgZfs.requestEncryptionCredentials -> cfgZfs.enableUnstable; + message = "This feature is only available for zfs unstable. Set the NixOS option boot.zfs.enableUnstable."; + } + ]; + + virtualisation.lxd.zfsSupport = true; + + boot = { + kernelModules = [ "zfs" ] ++ optional (!cfgZfs.enableUnstable) "spl"; + extraModulePackages = with packages; [ zfs ] ++ optional (!cfgZfs.enableUnstable) spl; + }; + + boot.initrd = mkIf inInitrd { + kernelModules = [ "zfs" ] ++ optional (!cfgZfs.enableUnstable) "spl"; + extraUtilsCommands = + '' + copy_bin_and_libs ${packages.zfsUser}/sbin/zfs + copy_bin_and_libs ${packages.zfsUser}/sbin/zdb + copy_bin_and_libs ${packages.zfsUser}/sbin/zpool + ''; + extraUtilsCommandsTest = mkIf inInitrd + '' + $out/bin/zfs --help >/dev/null 2>&1 + $out/bin/zpool --help >/dev/null 2>&1 + ''; + postDeviceCommands = concatStringsSep "\n" (['' + ZFS_FORCE="${optionalString cfgZfs.forceImportRoot "-f"}" + + for o in $(cat /proc/cmdline); do + case $o in + zfs_force|zfs_force=1) + ZFS_FORCE="-f" + ;; + esac + done + ''] ++ [(importLib { + # See comments at importLib definition. + zpoolCmd = "zpool"; + awkCmd = "awk"; + inherit cfgZfs; + })] ++ (map (pool: '' + echo -n "importing root ZFS pool \"${pool}\"..." + # Loop across the import until it succeeds, because the devices needed may not be discovered yet. + if ! poolImported "${pool}"; then + for trial in `seq 1 60`; do + poolReady "${pool}" > /dev/null && msg="$(poolImport "${pool}" 2>&1)" && break + sleep 1 + echo -n . + done + echo + if [[ -n "$msg" ]]; then + echo "$msg"; + fi + poolImported "${pool}" || poolImport "${pool}" # Try one last time, e.g. to import a degraded pool. + fi + ${lib.optionalString cfgZfs.requestEncryptionCredentials '' + zfs load-key -a + ''} + '') rootPools)); + }; + + boot.loader.grub = mkIf inInitrd { + zfsSupport = true; + }; + + environment.etc."zfs/zed.d".source = "${packages.zfsUser}/etc/zfs/zed.d/"; + + system.fsPackages = [ packages.zfsUser ]; # XXX: needed? zfs doesn't have (need) a fsck + environment.systemPackages = [ packages.zfsUser ] + ++ optional enableAutoSnapshots autosnapPkg; # so the user can run the command to see flags + + services.udev.packages = [ packages.zfsUser ]; # to hook zvol naming, etc. + systemd.packages = [ packages.zfsUser ]; + + systemd.services = let + getPoolFilesystems = pool: + filter (x: x.fsType == "zfs" && (fsToPool x) == pool) config.system.build.fileSystems; + + getPoolMounts = pool: + let + mountPoint = fs: escapeSystemdPath fs.mountPoint; + in + map (x: "${mountPoint x}.mount") (getPoolFilesystems pool); + + createImportService = pool: + nameValuePair "zfs-import-${pool}" { + description = "Import ZFS pool \"${pool}\""; + requires = [ "systemd-udev-settle.service" ]; + after = [ "systemd-udev-settle.service" "systemd-modules-load.service" ]; + wantedBy = (getPoolMounts pool) ++ [ "local-fs.target" ]; + before = (getPoolMounts pool) ++ [ "local-fs.target" ]; + unitConfig = { + DefaultDependencies = "no"; + }; + serviceConfig = { + Type = "oneshot"; + RemainAfterExit = true; + }; + script = (importLib { + # See comments at importLib definition. + zpoolCmd="${packages.zfsUser}/sbin/zpool"; + awkCmd="${pkgs.gawk}/bin/awk"; + inherit cfgZfs; + }) + '' + poolImported "${pool}" && exit + echo -n "importing ZFS pool \"${pool}\"..." + # Loop across the import until it succeeds, because the devices needed may not be discovered yet. + for trial in `seq 1 60`; do + poolReady "${pool}" && poolImport "${pool}" && break + sleep 1 + done + poolImported "${pool}" || poolImport "${pool}" # Try one last time, e.g. to import a degraded pool. + if poolImported "${pool}"; then + ${optionalString cfgZfs.requestEncryptionCredentials "\"${packages.zfsUser}/sbin/zfs\" load-key -r \"${pool}\""} + echo "Successfully imported ${pool}" + else + exit 1 + fi + ''; + }; + + # This forces a sync of any ZFS pools prior to poweroff, even if they're set + # to sync=disabled. + createSyncService = pool: + nameValuePair "zfs-sync-${pool}" { + description = "Sync ZFS pool \"${pool}\""; + wantedBy = [ "shutdown.target" ]; + unitConfig = { + DefaultDependencies = false; + }; + serviceConfig = { + Type = "oneshot"; + RemainAfterExit = true; + }; + script = '' + ${packages.zfsUser}/sbin/zfs set nixos:shutdown-time="$(date)" "${pool}" + ''; + }; + createZfsService = serv: + nameValuePair serv { + after = [ "systemd-modules-load.service" ]; + wantedBy = [ "zfs.target" ]; + }; + + in listToAttrs (map createImportService dataPools ++ + map createSyncService allPools ++ + map createZfsService [ "zfs-mount" "zfs-share" "zfs-zed" ]); + + systemd.targets."zfs-import" = + let + services = map (pool: "zfs-import-${pool}.service") dataPools; + in + { + requires = services; + after = services; + wantedBy = [ "zfs.target" ]; + }; + + systemd.targets."zfs".wantedBy = [ "multi-user.target" ]; + }) + + (mkIf enableAutoSnapshots { + systemd.services = let + descr = name: if name == "frequent" then "15 mins" + else if name == "hourly" then "hour" + else if name == "daily" then "day" + else if name == "weekly" then "week" + else if name == "monthly" then "month" + else throw "unknown snapshot name"; + numSnapshots = name: builtins.getAttr name cfgSnapshots; + in builtins.listToAttrs (map (snapName: + { + name = "zfs-snapshot-${snapName}"; + value = { + description = "ZFS auto-snapshotting every ${descr snapName}"; + after = [ "zfs-import.target" ]; + serviceConfig = { + Type = "oneshot"; + ExecStart = "${zfsAutoSnap} ${cfgSnapFlags} ${snapName} ${toString (numSnapshots snapName)}"; + }; + restartIfChanged = false; + }; + }) snapshotNames); + + systemd.timers = let + timer = name: if name == "frequent" then "*:0,15,30,45" else name; + in builtins.listToAttrs (map (snapName: + { + name = "zfs-snapshot-${snapName}"; + value = { + wantedBy = [ "timers.target" ]; + timerConfig = { + OnCalendar = timer snapName; + Persistent = "yes"; + }; + }; + }) snapshotNames); + }) + + (mkIf enableAutoScrub { + systemd.services.zfs-scrub = { + description = "ZFS pools scrubbing"; + after = [ "zfs-import.target" ]; + serviceConfig = { + Type = "oneshot"; + }; + script = '' + ${packages.zfsUser}/bin/zpool scrub ${ + if cfgScrub.pools != [] then + (concatStringsSep " " cfgScrub.pools) + else + "$(${packages.zfsUser}/bin/zpool list -H -o name)" + } + ''; + }; + + systemd.timers.zfs-scrub = { + wantedBy = [ "timers.target" ]; + after = [ "multi-user.target" ]; # Apparently scrubbing before boot is complete hangs the system? #53583 + timerConfig = { + OnCalendar = cfgScrub.interval; + Persistent = "yes"; + }; + }; + }) + ]; +} |