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SOLVED Guidance re: backing up TimeMachine folders using SMB

Western Digital Drives - The Preferred Drives of FreeNAS and TrueNAS CORE

Constantin

Vampire Pig
Joined
May 19, 2017
Messages
1,380
Good evening,

As I have mentioned elsewhere, I am in the process of switching from FreeNAS 11.3 U5 to TrueNAS. As part of that process, I have left AFP behind and am using SMB-only. Most shares work without a hitch, however, backing up Time Machine shares is still problematic.

Background:
In the past, I assigned each machine / user two logins - one for their "regular" credentials, the second one for time machine. Each time machine account is also part of the time_machine group. This setup allowed my main user account to be the owner of the share while other users backed up using their group credentials. Each user was assigned a separate share with a quota to limit the space that Time Machine could take up. Since I was the owner, it allowed me to back everything up to a external RAID that is readable by my Mac.

Problem:
Since I graduated to SMB, I am having no luck "seeing" the time machine sparsebundles that I know are on the machine. They show up just fine from the CLI by wandering into the pool but when I try to mount the parent directory, all the user-related directories are hidden, and the system creates a separate directory under my user name. Thus, if I started off with two directories ("backup_user_a, backup_user_b), I'll now have three (backup_user_a, backup_user_b, user_a). The system will not allow me to mount the parent directory nor will Samba allow me to back up the time machine sparsebundles, because I cannot mount the associated directories unless I use the backup_user login credentials to mount them.

So, is there a way to structure a SMB share to
  • Have multiple Time Machine shares with individual quotas; and
  • A parent directory share, that allows all the time machine-related subdirectories to be backed up in one rsync operation? I don't need write permissions, etc. I just want to be able to read and traverse the contents to mount the share and all its sub-directories on my MacOS desktop so I can back it all up.
 

Constantin

Vampire Pig
Joined
May 19, 2017
Messages
1,380
With the help of @anodos, I was able to resolve this issue. He guided me through the process of proper share creation, and I also kept SMB off while all the shares, their permissions, etc. were being redone. In particular, for normal shares whose contents you want to share among multiple users, be sure not to select "private shares", etc. but rather start with a clean slate and enable all the settings you want manually.

For a general-access share, there should be no U% prefix. Otherwise, you create private shares / accounts. They are very hard to undo also, so now I get to repopulate my server for the third time.

The posting below is what also happened this afternoon.

I/O suddenly slowed to a crawl. renaming files takes 10+ seconds, even deleting empty files in a share takes over 5 seconds each. My CPU utilization for one core is consistently 100% (SMBD) yet I don't know why the I/O should be slow considering a 10GbE connection, a Optane SLOG, a sVDEV metadata/small files pool, and oodles of free HDD space (pool is 25% full).

Where should I start looking?
 
Last edited:

c77dk

Member
Joined
Nov 27, 2019
Messages
240
Where should I start looking?
Only thing that comes to mind is "gstat" - but it sounds totally strange that it has dropped like that
 

Constantin

Vampire Pig
Joined
May 19, 2017
Messages
1,380
Screen Shot 2021-04-07 at 2.09.38 PM.png


It doesn't look terribly busy. Pool health is good also.
 

Constantin

Vampire Pig
Joined
May 19, 2017
Messages
1,380
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