As documented in [1]
If the number next to "GotSomeSpaces" or any of the "GSS*" fields is
greater than 0, then the fileserver ran out of callback space and had
to prematurely revoke callback promises from clients in order to free
up space.
Here's our stats on afs01:
$ xstat_fs_test localhost -collID 3 -onceonly
Starting up the xstat_fs service, no debugging, one-shot operation
------------------------------------------------------------
13547865 DeleteFiles
1849223729 DeleteCallBacks
45049055 BreakCallBacks
2098382037 AddCallBack
174 GotSomeSpaces
7800 DeleteAllCallBacks
20778 nFEs
21184 nCBs
1500000 nblks
43425561 CBsTimedOut
0 nbreakers
8 GSS1
4 GSS2
5 GSS3
169 GSS4
4 GSS5
So as noted, the server ran out of callback spaces a few times.
Raising it takes only a little memory, but will help performance.
Thanks to Jeffrey Altman (auristor) for pointing this out.
[1] https://www.openafs.org/pages/newsletter/newsletter-2013-03-volume004-issue05.html
Change-Id: I2ad33dd8918cb559634d2c5b8c4e4e7f2d6d4051
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