Cannot find out what uses space in ZFS dataset
Date: Thu, 18 Sep 2025 10:10:23 UTC
Hello. I've got a urgent trouble I'm trying to solve. I need to take backups of a server: they should be around 4-5 GBs, but the end up close to 100GB!!! The trouble is with the zroot/ROOT/default dataset: > # cd / > # du -d 0 -h -x > 3.3G . Yet: > root@chet:/ # zfs list|grep ROOT > zroot/ROOT 70.9G 1.94T 88K none > zroot/ROOT/default 70.9G 1.94T 62.1G / So ho do we go from 3.3G to 62.1G??? There are snapshots, but I'm using plain "zfs send", so they should not matter... > # zfs get all zroot/ROOT/default > NAME PROPERTY VALUE SOURCE > zroot/ROOT/default type filesystem - > zroot/ROOT/default creation Sun Dec 15 16:58 2019 - > zroot/ROOT/default used 70.9G - > zroot/ROOT/default available 1.94T - > zroot/ROOT/default referenced 62.1G - > zroot/ROOT/default compressratio 1.62x - > zroot/ROOT/default mounted yes - > zroot/ROOT/default quota none default > zroot/ROOT/default reservation none default > zroot/ROOT/default recordsize 128K default > zroot/ROOT/default mountpoint / local > zroot/ROOT/default sharenfs off default > zroot/ROOT/default checksum on default > zroot/ROOT/default compression lz4 inherited from zroot > zroot/ROOT/default atime off inherited from zroot > zroot/ROOT/default devices on default > zroot/ROOT/default exec on default > zroot/ROOT/default setuid on default > zroot/ROOT/default readonly off local > zroot/ROOT/default jailed off default > zroot/ROOT/default snapdir hidden default > zroot/ROOT/default aclmode discard default > zroot/ROOT/default aclinherit restricted default > zroot/ROOT/default createtxg 8 - > zroot/ROOT/default canmount noauto local > zroot/ROOT/default xattr on default > zroot/ROOT/default copies 1 default > zroot/ROOT/default version 5 - > zroot/ROOT/default utf8only off - > zroot/ROOT/default normalization none - > zroot/ROOT/default casesensitivity sensitive - > zroot/ROOT/default vscan off default > zroot/ROOT/default nbmand off default > zroot/ROOT/default sharesmb off default > zroot/ROOT/default refquota none default > zroot/ROOT/default refreservation none default > zroot/ROOT/default guid 13999796839276270198 - > zroot/ROOT/default primarycache all default > zroot/ROOT/default secondarycache all default > zroot/ROOT/default usedbysnapshots 8.76G - > zroot/ROOT/default usedbydataset 62.1G - > zroot/ROOT/default usedbychildren 0B - > zroot/ROOT/default usedbyrefreservation 0B - > zroot/ROOT/default logbias latency default > zroot/ROOT/default objsetid 89 - > zroot/ROOT/default dedup off default > zroot/ROOT/default mlslabel none default > zroot/ROOT/default sync standard default > zroot/ROOT/default dnodesize legacy default > zroot/ROOT/default refcompressratio 1.56x - > zroot/ROOT/default written 1.79M - > zroot/ROOT/default logicalused 114G - > zroot/ROOT/default logicalreferenced 96.6G - > zroot/ROOT/default volmode default default > zroot/ROOT/default filesystem_limit none default > zroot/ROOT/default snapshot_limit none default > zroot/ROOT/default filesystem_count none default > zroot/ROOT/default snapshot_count none default > zroot/ROOT/default snapdev hidden default > zroot/ROOT/default acltype nfsv4 default > zroot/ROOT/default context none default > zroot/ROOT/default fscontext none default > zroot/ROOT/default defcontext none default > zroot/ROOT/default rootcontext none default > zroot/ROOT/default relatime on default > zroot/ROOT/default redundant_metadata all default > zroot/ROOT/default overlay on default > zroot/ROOT/default encryption off default > zroot/ROOT/default keylocation none default > zroot/ROOT/default keyformat none default > zroot/ROOT/default pbkdf2iters 0 default > zroot/ROOT/default special_small_blocks 0 default > zroot/ROOT/default snapshots_changed Thu Sep 18 12:00:02 2025 - > zroot/ROOT/default prefetch all default > zroot/ROOT/default autobackup:auto_zroot true inherited from zroot usedbydataset is 62.1G!!! Where can this come from if du says 3.3??? bye & Thanks av.