SOLVED Defect 36508 - Windows report cluster size of 1MB used for small file in a SMB share, ZFS says 128kb

[Mark Holtz]

Sigh.... I opened up Defect 36508 about the cluster size being reported as being 1MB. I had included steps to reproduce as well as screen shots. Unfortunately, it got closed last week as "unable to reproduce".

What did I do wrong in filing this defect?

 

[kdragon75]

Are you talking about the ZFS record size? That's variable.

 

[kdragon75]

I think I see what you mean, I have a 90,832 byte file (as reported by windows on a SMB share) and Windows is reporting a size on disk of 3,145,728 bytes. I'm not sure but this may take into account parity, mirrors, and all metadata and once you factor record size...
Mehh that's still WAY off.

 

[MrToddsFriends]

Sigh.... I opened up Defect 36508 about the cluster size being reported as being 1MB.

Presumably a consequence of the default value of 1048576 for the allocation roundup size parameter in Samba. I'm seeing this for ages (with no further bad side effects so far).
https://www.samba.org/samba/docs/current/man-html/smb.conf.5.html

 

[kdragon75]

Yeah I just checked via ssh and the file is no larger than expected on disk.

 

[Mark Holtz]

Aha... I knew it was something in the interconnectivity between SaMBa and FreeBSD. I've updated the defect with the following workaround:

1. Log into Administration Console
2. Go to Services
3. Under SMB, click Stop Now (this will stop Windows shares)
4. Under SMB, click on the Wrench icon for Settings
5. Under Auxiliary parameters:, type
   Code:

   allocation roundup size = 131072

   . This will set the allocation units for all shares to be 128KB (128KB=131072)
6. Clock OK to close out of settings.
7. In the Services menu, under SMB, click on Start Now (this will start Windows shares)

Here is a screen shot of the steps:

 

[Mark Holtz]

I have submitted feature request 38525: Samba: Default allocation roundup size is set to 1048576, should be 131072 (and user adjustable) for this issue. Since it is a newly-submitted issue, it is currently set to Private.

 

[Mark Holtz]

Update on defect 36508: It has been closed and flagged as "behaving as intended".