AFP connections dropping on 10.8.5 Server

Question

We are experiencing a very odd problem when AFP connections to our server are dropping part way through, which often then makes the client machine crash and force a hard reboot.
AFP logs on the server show nothing, but the /var/log/system.log events below show the disconnection as it happens.
Note I have installed the 10.8.5 Combo Updater, reinstalled the Server.app from the AppStore, experienced the same on various client machines, and seen the same problem.
We have plenty of disk space on both sides and the folder in question are about 40GB.
Disk Warrior on both ends has been used already, nothing interesting found.
Oddly enough connecting via SMB does not cause these problems.
Originally I thought it might be network related, but I tried connecting an Ethernet cable directly between client and server (bypassing the switch) and saw the same problem.
I can only surmise a recent OSX update (not sure if this problem is on the server end or client end) caused this problem.
Here are the log details:
Oct  7 18:28:14 frankie.example.com KernelEventAgent[46]: tid 00000000 received event(s) VQ_NOTRESP (1)
Oct  7 18:28:14 frankie.example.com KernelEventAgent[46]: tid 00000000 type 'afpfs', mounted on '/Volumes/INCOMING', from '//[email protected]/INCOMING', not responding
Oct  7 18:28:14 frankie kernel[0]: ASP_TCP Disconnect: triggering reconnect by bumping reconnTrigger from curr value 0 on so 0xffffff801e112ef0
Oct  7 18:28:14 frankie kernel[0]: AFP_VFS afpfs_DoReconnect started /Volumes/INCOMING prevTrigger 0 currTrigger 1
Oct  7 18:28:14 frankie kernel[0]: AFP_VFS afpfs_DoReconnect:  doing reconnect on /Volumes/INCOMING
Oct  7 18:28:14 frankie kernel[0]: AFP_VFS afpfs_DoReconnect:  posting to KEA EINPROGRESS for /Volumes/INCOMING
Oct  7 18:28:14 frankie kernel[0]: AFP_VFS afpfs_DoReconnect:  Max reconnect time: 30 secs, Connect timeout: 15 secs for /Volumes/INCOMING
Oct  7 18:28:14 frankie kernel[0]: AFP_VFS afpfs_DoReconnect:  connect to the server /Volumes/INCOMING
Oct  7 18:28:14 frankie kernel[0]: AFP_VFS afpfs_DoReconnect:  Logging in with uam 10 /Volumes/INCOMING
Oct  7 18:28:14 frankie.example.com KernelEventAgent[46]: tid 00000000 found 1 filesystem(s) with problem(s)
Oct  7 18:28:14 frankie kernel[0]: AFP_VFS afpfs_DoReconnect:  Restoring session /Volumes/INCOMING
Any ideas, suggestions appreciated!

Answer 1

Please take each of the following steps until the problem is resolved. Back up all data before making any changes.
Step 1
Delete all sharepoints in the File Sharing tab of the Sharing preference pane. Recreate them one at a time and test each one.
Step 2
Boot into Recovery mode, launch Disk Utility, select the startup volume, and run Repair Disk (not  Repair Permissions.) If any problems are found, repeat. Then reboot as usual.
If any sharepoints are on a different volume, repair it too.
Step 3
Boot the server in safe mode and test. Note: If FileVault is enabled on some models, or if a firmware password is set, or if the boot volume is a software RAID, you can’t do this. After testing, reboot as usual and verify that you still have the problem.
Step 4
Triple-click anywhere in the line below on this page to select it:
/Library/Preferences/com.apple.ByteRangeLocking.plist
Right-click or control-click the line and select 
Services ▹ Reveal
from the contextual menu.* A folder should open with an item selected. Move the selected item to the Trash. Repeat with this line:
/var/db/BRLM.db
Reboot.
*If you don't see the contextual menu item, copy the selected text to the Clipboard (command-C). In the Finder, select
Go ▹ Go to Folder...
from the menu bar, paste into the box that opens (command-V). You won't see what you pasted because a line break is included. Press return.
Step 5
Reinstall the OS. You don't need to erase the startup volume, and you won't need your backup unless something goes wrong. If your Mac was upgraded from an older version of OS X, you’ll need the Apple ID and password you used to upgrade.
If you installed the Java runtime distributed by Apple and still need it, you'll have to reinstall it.