diff options
| author | Rick Macklem <rmacklem@FreeBSD.org> | 2021-09-18 21:38:43 +0000 |
|---|---|---|
| committer | Rick Macklem <rmacklem@FreeBSD.org> | 2021-09-18 21:38:43 +0000 |
| commit | ad6dc365202390edffb14d725155e230b96f59ae (patch) | |
| tree | 7d7f3093f1c1d51283e456f4c15ad0aa996c7e57 /release | |
| parent | 7b2ac8eb9be76c96356b6e9a7c06a8080ea841ae (diff) | |
| download | src-ad6dc365202390edffb14d725155e230b96f59ae.tar.gz src-ad6dc365202390edffb14d725155e230b96f59ae.zip | |
nfscl: Use vfs.nfs.maxalloclen to limit Deallocate RPC RTT
Unlike Copy, the NFSv4.2 Allocate and Deallocate operations do not
allow a reply with partial completion. As such, the only way to
limit the time the operation takes to provide a reasonable RPC RTT
is to limit the size of the allocation/deallocation in the NFSv4.2
client.
This patch uses the sysctl vfs.nfs.maxalloclen to set
the limit on the size of the Deallocate operation.
There is no way to know how long a server will take to do an
deallocate operation, but 64Mbytes results in a reasonable
RPC RTT for the slow hardware I test on.
For an 8Gbyte deallocation, the elapsed time for doing it in 64Mbyte
chunks was the same (within margin of variability) as the
elapsed time taken for a single large deallocation
operation for a FreeBSD server with a UFS file system.
Diffstat (limited to 'release')
0 files changed, 0 insertions, 0 deletions