[Samba] No luck with Time Machine and 4.23.5

Stefan Bethke stb at lassitu.de
Fri Jan 30 08:48:59 UTC 2026 

I have a few Macs backup up to my Samba server, and this has worked without a hitch for many years.

While trying to restart a backup on a machine where Time Machine was unhappy, I decided to wipe the share and start over fresh. Since then, Time Machine gets stuck after about 3.8 GB, never progressing any further. Another Mac is happily backing up to the same server.

The server is Debian Trixie with the backport packages (2:4.23.5+dfsg-1~bpo13+1), the Mac is running 26.2.

On the Mac, I'm getting these errors (slightly redacted):

$ printf '\e[3J' && log show --predicate 'subsystem == "com.apple.TimeMachine"' --info --last 30m | grep -F 'eMac' | grep -Fv 'etat' | awk -F']' '{print substr($0,1,19), $NF}'
2026-01-30 09:20:55  Choosing destination volume
2026-01-30 09:20:56  Prepare destination
2026-01-30 09:20:56  mountNetworkURL: smb://stb@REDACTED/Backup%20gray airDiskFlags: 0x0
2026-01-30 09:20:56  NetAuth session for 'smb://stb@REDACTED/Backup%20gray' will use options: {
    AuthType = Time     AuthType = TimeMachine;
2026-01-30 09:20:56  Reporting preparation progress message: 'Mounting “Backup gray” from “REDACTED”…', fractionDone: nil
2026-01-30 09:20:58  NAOpenSessionAsync reports sessionStatus: 0, sessionInfo: {
2026-01-30 09:20:58  Mounting share 'Backup gray' with options: {
    TimeMachineMoun     TimeMachineMount = 1;
2026-01-30 09:20:58  NAMountAsync reports mountStatus: 0, mountInfo: {
2026-01-30 09:20:58  Reporting preparation progress message: 'Checking capabilities of “Backup gray” from “REDACTED”…', fractionDone: nil
2026-01-30 09:20:58  Initial network volume options for 'Backup gray' are {disablePrimaryReconnect: 0, disableSecondaryReconnect: 0, reconnectTimeOut: 0, QoS: 0x0, attributes: 0x1C}
2026-01-30 09:20:58  Setting network volume options for 'Backup gray' to {disablePrimaryReconnect: 0, disableSecondaryReconnect: 1, reconnectTimeOut: 30, QoS: 0x20, attributes: 0x1C}
2026-01-30 09:20:58  Fsctl reported error while setting network volume options for 'Backup gray', error: 7 Argument list too long
2026-01-30 09:20:58  Current network volume options for 'Backup gray' are {disablePrimaryReconnect: 0, disableSecondaryReconnect: 0, reconnectTimeOut: 30, QoS: 0x0, attributes: 0x1C}
2026-01-30 09:20:58  Ignoring E2BIG error while setting network volume options for 'Backup gray
2026-01-30 09:20:59  Stored password in system keychain for account 'stb', url 'smb://stb@REDACTED/Backup%20gray'
2026-01-30 09:20:59  Choosing destination options
...
2026-01-30 09:21:26  User tried to start a backup
2026-01-30 09:21:26  Backup requested to next destination in rotation. specifiedOptions: TMBackupOptions(rawValue: 0)
2026-01-30 09:21:26  lastDestinationID: 976F41AD-BFAE-49A6-BC52-3C534CA920A1; nextDestinationID: 976F41AD-BFAE-49A6-BC52-3C534CA920A1
2026-01-30 09:21:26  Not rotating backup destinations, next destination is the same as the last destination.
2026-01-30 09:21:26  Attempting backup with mode "manual backup"
2026-01-30 09:21:26 > { AssertionType '(null)' (4), Assertion Retain: (1)} - device locking is prevented
2026-01-30 09:21:26  Device locking is prevented.
2026-01-30 09:21:26  Mounting destination 976F41AD-BFAE-49A6-BC52-3C534CA920A1 for backing up
2026-01-30 09:21:26  Rejecting candidate mount point: /Volumes/Backup gray, not owned by root
2026-01-30 09:21:26  Attempting to mount 'smb://stb@REDACTED/Backup%20gray'
2026-01-30 09:21:27  Failed to read capabilities for '/Volumes/Backup gray', error: Operation not permitted
2026-01-30 09:21:27  Failed to read capabilities for '/Volumes/Backup gray', error: Operation not permitted
2026-01-30 09:21:27  Failed to read capabilities for '/Volumes/Backup gray', error: Operation not permitted
2026-01-30 09:21:27  Failed to read capabilities for '/Volumes/Backup gray', error: Operation not permitted
2026-01-30 09:21:27  Mounted 'smb://stb@REDACTED/Backup%20gray' at '/Volumes/.timemachine/REDACTED/8EFC83A6-7B92-4DD7-A168-299E3BCBD023/Backup gray'
2026-01-30 09:21:27  Initial network volume options for 'Backup gray' are {disablePrimaryReconnect: 0, disableSecondaryReconnect: 0, reconnectTimeOut: 0, QoS: 0x0, attributes: 0x1C}
2026-01-30 09:21:27  Setting network volume options for 'Backup gray' to {disablePrimaryReconnect: 0, disableSecondaryReconnect: 1, reconnectTimeOut: 30, QoS: 0x20, attributes: 0x1C}
2026-01-30 09:21:27  Current network volume options for 'Backup gray' are {disablePrimaryReconnect: 0, disableSecondaryReconnect: 0, reconnectTimeOut: 30, QoS: 0x20, attributes: 0x1C}
2026-01-30 09:21:28  attrVolumeWithMountPoint 'file:///Volumes/.timemachine/REDACTED/8EFC83A6-7B92-4DD7-A168-299E3BCBD023/Backup%20gray/' failed, error: Error Domain=NSPOSIXErrorDomain Code=13 "Permission denied"
2026-01-30 09:21:28  Mountpoint '/Volumes/.timemachine/REDACTED/8EFC83A6-7B92-4DD7-A168-299E3BCBD023/Backup gray' is still valid
2026-01-30 09:21:28  Mountpoint '/Volumes/.timemachine/REDACTED/8EFC83A6-7B92-4DD7-A168-299E3BCBD023/Backup gray' supports required network capabilities (4.4 TB of 4.4 TB available)
2026-01-30 09:21:30  attrVolumeWithMountPoint 'file:///Volumes/.timemachine/REDACTED/8EFC83A6-7B92-4DD7-A168-299E3BCBD023/Backup%20gray/' failed, error: Error Domain=NSPOSIXErrorDomain Code=13 "Permission denied"
2026-01-30 09:21:30  Mountpoint '/Volumes/.timemachine/REDACTED/8EFC83A6-7B92-4DD7-A168-299E3BCBD023/Backup gray' is still valid
2026-01-30 09:21:30  Creating an unencrypted sparsebundle diskimage at /Volumes/.timemachine/REDACTED/8EFC83A6-7B92-4DD7-A168-299E3BCBD023/Backup gray/gray 2026-01-30-092130.incomplete
2026-01-30 09:21:31  Using a band size of 1.07 GB (on a volume with size of 4.4 TB)
...
2026-01-30 09:21:44  attrVolumeWithMountPoint 'file:///Volumes/.timemachine/REDACTED/8EFC83A6-7B92-4DD7-A168-299E3BCBD023/Backup%20gray/' failed, error: Error Domain=NSPOSIXErrorDomain Code=13 "Permission denied"
2026-01-30 09:21:45  Failed to find Time Machine volume on '/Volumes/.timemachine/REDACTED/8EFC83A6-7B92-4DD7-A168-299E3BCBD023/Backup gray/gray 2026-01-30-092130.incomplete', found:
2026-01-30 09:21:45  Backup volume device entry did not appear in IOKit registry in a timely manner!
2026-01-30 09:21:45  Erasing 'Backups of gray' as Case-sensitive APFS
2026-01-30 09:21:45  attrVolumeWithMountPoint 'file:///Volumes/.timemachine/REDACTED/8EFC83A6-7B92-4DD7-A168-299E3BCBD023/Backup%20gray/' failed, error: Error Domain=NSPOSIXErrorDomain Code=13 "Permission denied"
2026-01-30 09:21:46  attrVolumeWithMountPoint 'file:///Volumes/.timemachine/REDACTED/8EFC83A6-7B92-4DD7-A168-299E3BCBD023/Backup%20gray/' failed, error: Error Domain=NSPOSIXErrorDomain Code=13 "Permission denied"

The permission denied error then repeats until I cancel the backup. Time Machine reports that it wrote about 3.8 GB, then it never progresses.

Share filesystem permission:
# ls -al /shared/backup/gray/
total 101
drwxr-xr-x  3 stb root         4 Jan 30 08:40 .
drwxrwxr-x 16 stb lassitude   16 Jan 29 23:42 ..
-rw-r--r--  1 stb lassitude 6148 Jan 29 17:28 .DS_Store
drwxr-xr-x  4 stb lassitude   13 Jan 30 08:40 gray.sparsebundle

(I've not set any ACLs).

smb.conf:
[global]
   workgroup = LASSITUDE
   server string = REDACTED
   security = user
   ; load printers = yes
   ; printing = cups
   max log size = 50
   interfaces = 44.128.77.1/26
   ;log level = 3
   log file = /var/log/samba/smb-%m.log
   min protocol = SMB2
   vfs objects = fruit streams_xattr
   fruit:metadata = stream
   fruit:model = MacSamba
   fruit:posix_rename = yes
   fruit:veto_appledouble = no
   fruit:wipe_intentionally_left_blank_rfork = yes
   fruit:delete_empty_adfiles = yes
   fruit:aapl = yes
   fruit:copyfile = yes
   hide files = /.DS_Store/Network Trash Folder/TheFindByContentFolder/TheVolumeSettingsFolder/Temporary Items/.TemporaryItems/.VolumeIcon.icns/Icon?/.FBCIndex/.FBCLockFolder/

[Backup gray]
    path = /shared/backup/gray
    writeable = yes
    vfs objects = fruit streams_xattr
    fruit:time machine = yes


Any suggestions?



-- 
Stefan Bethke <stb at lassitu.de>   Fon +49 175 3288861

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 488 bytes
Desc: Message signed with OpenPGP
URL: <http://lists.samba.org/pipermail/samba/attachments/20260130/0ff3f67b/signature.sig>

More information about the samba mailing list