On Aug 10, 2009, at 3:43 PM, Carlos André wrote:
No, i'm just using packages from CentOS repo...
And u're right about expo retries... with tcpdump i've monitored
traffic and i got SYN retries in 3, 6, 12, 24, 48, 96 secs on port
2049...
I tried use "retry=1" option on mount without any change...
That won't have any effect on the kernel's TCP connect behavior. It
is simply used by the mount command to know when to stop redriving
mount(2) system calls. The current mount command doesn't actually
interrupt the mount(2) system call if it's taking longer than the
specified "retry=" setting.
I don't want change source or tcp timers... just NFSv4 client.
I don't know of any way to effect a change in the kernel's TCP connect
behavior short of a code change, and that would affect all RPC/TCP
programs.
Basically the server is down. I suppose the client's kernel can
detect this is the case as soon as the ARP request for the server's
MAC address times out, but normally we retry TCP connects for a while
(even in this case) because we assume the server is coming back up as
quickly as it can, and want to catch it as quickly as possible.
But we can't shorten this timeout in the general case, I don't think.
It could take quite a while on a busy network or if a long round trip
is involved for a TCP connect to complete.
2009/8/10 Chuck Lever <chuck.lever@xxxxxxxxxx>:
On Aug 10, 2009, at 2:29 PM, Carlos André wrote:
Bruce, no... you're right. I'm describing a situation where my
server
died... i need mount fail faster (10 or 15 secs max) than 3 minutes
and 9 seconds...
The 189 second timeout is likely how long it takes the kernel to
give up
trying to connect a TCP socket to the server (6 SYN attempts with
exponential retries, or something like that). For stock CentOS
5.3, I think
user space does only a DNS lookup for normal NFSv4 mounts -- the
kernel just
tries to connect a TCP socket to port 2049, with no preceding rpcbind
request.
Carlos, let us know if you have replaced any NFS-related CentOS
components
(kernel, nfs-utils) with something you've built yourself.
2009/8/7 J. Bruce Fields <bfields@xxxxxxxxxxxx>:
On Fri, Aug 07, 2009 at 09:42:18AM +0300, Benny Halevy wrote:
On Aug. 07, 2009, 3:18 +0300, Carlos André <candrecn@xxxxxxxxx>
wrote:
Anyone ?
2009/7/29 Carlos André <candrecn@xxxxxxxxx>:
PPL, I need put a CentOS 5.3 (updated) NFSv4 server to work with
Kerberos
and AutoFS, but i got a problem: If NFS server goes down i get a
LOOOOOOONG
mount timeout on CentOS 5.3 (updated) NFSv4 client...
Since i need mount some (3 to 6) dirs at user logon process,
if mount
hangs,
user logon hangs. Then i want configure it to timeout (if
server down)
after
10-15 secs (MAX) on each mount attempt.
I already make a lab and tried a LOT of combinations, there my
findings
(server DOWN IP: 172.16.0.10 / client IP: 172.16.1.10) using
basic
command
(time mount 172.16.0.10:/remotedir /localdir/ -t nfs4 -o
sec=krb5,proto=<tcp/udp>) from NFS client:
- Once i try access mount point using AutoFS (proto=tcp OR
proto=udp)
it
hangs for 189 secs (3m9s: real 3m9.001s) until show error
(mount:
mount to
NFS server '172.16.0.10' failed: timed out (giving up))
Sounds like you're hitting the server's grace period.
I thought he was describing a situation where the server the server
is completely gone and isn't coming back, and wondering how to
make the
mount fail faster. But I may be misunderstanding.
--b.
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Chuck Lever
chuck[dot]lever[at]oracle[dot]com
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chuck[dot]lever[at]oracle[dot]com
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