0x8007003B timeout copying large file to Samba server

PROBLEM: 0x8007003B timeout copying large file to Samba server

SOLUTION: This is an SMB.CONF issue, solved / fixed with this line:

strict allocate = no

DESCRIPTION: I had this issue for a long time, and mostly the web mocks people, tells them to do stupid things, or generally is unhelpful.  Lots of 2GB, or “your network” or “your firewall” or “turn off DPI” or whatever, none of it applicable to me.  I just accepted it, but decided to dig a little deeper today.

The exact amount of data written before it fails would vary, but the size from LS would always be the full file size.  Higher performance filesystems such as XFS, EXT4, JFS, all of them on NVMe arrays, I found I could get about 55GB allocated before timeout.  On spinning disk, it was much less, which is probably why many people fell down the rabbit hole of claiming 2GB limits, etc.

Strict Allocate = YES tells it to allocate the whole file upon request, which is what Windows does.  Samba says “OK, hold on”, and then times out.  Some people used powershell on a client to change the smbclient timeout to 600 seconds, or whatever, but that’s not really ideal, since it does not scale.

Strict Allocate = NO says to use normal UNIX semantics, where the file has no pre-allocated blocks, and allocates blocks only as the data comes in.  This starts with a fully sparse file, and data copy status on the windows client shows it processing immediately.  This is what we want for large files.  If it was only small files, then we don’t care.

I made this a global change.  I don’t need fully pre-allocated, non-sparse files on my file server.  It’s possible someone writing databases might need this, and you’d want to make sure you didn’t feed data faster than the kernel can allocate blocks.  Another one of those multiple filesystems kind of solutions.

When you play with tunables, you run into things that people don’t really know how to troubleshoot.  That’s what this is for, just so it shows up in web searches.

Outlook and huge internet calendars

The PST for Internet Calendars does not automatically compact.
Every sync is an entire, new copy saved into the PST.
I found my file is 42GB (I have about 10 calendars).

To see if you have the issue, check

If you have nothing gargantuan, then all’s well.

If your Internet Calendar Subscriptions.pst is huge:
1) you can compact it for now:
* Outlook
* File
* Account Settings
* Data Files
* Click on Internet Calendar Subs
* Click on Settings
* Compact now
* It takes 4-5 seconds per meg on SSD…

2) You can change how often this downloads.
* Outlook
* File
* Options
* Advanced
* Scroll down to Send and Receive
* Click Send/Receive button
* Edit your send/receive groups to sync Internet Calendars less frequently

3) You can set Outlook to automatically compact on close.
The drawback is that if you left it running a long time,
close might take hours. It’s also a registry change.
Because of this, I’m not listing steps for it,
but Uncle Google can help.