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.

LED 0088 on NIM install & Upgrade

RE: LED 0088 on NIM install & Upgrade
When performing a NIM restore + upgrade at the same time, you have to run no-prompt.
You do this my editing the bosinst.data file from the mksysb,
then you define and allocate that as a NIM resource.

One of the things you have to do is provide the target disks.
If the target disks do not exist, such as only one LUN when you thought there were two, the LPAR will HANG with LED 0088

You might see something like this on the console:
Cannot run a 64-bit program until the 64-bit
environment has been configured. See the system administrator.
eval /usr/lpp/bosinst/bi_io -c < /dev/console Erasing Disks Please wait... Approximate Elapsed time % tasks complete (in minutes) 0042-008 NIMstate: Request denied - Method_req Or you might see

but nothing more. It will just hang there indefinitely.

Give it 30 mins before you call it hung, but you might want to do an RTE install so you can go to the menus and verify you have the right disks listed.