Mailinglist Archive: opensuse (1256 mails)

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[opensuse] Re: Is 40 dropped packets out of 300,000 high? This is wired cat5 LAN
Greg Freemyer wrote:

[linda stats]
That's 8300 out of 1.286 billion. Well below 0.1%.

sudo tc -s qdisc ls dev eth0
qdisc mq 0: root
Sent 122904229458 bytes 90249084 pkt backlog 0b 0p requeues 1584046
Sent 122904054398 bytes 90246915 pkt backlog 0b 0p requeues 1584046
Sent 175060 bytes 2169 pkt
backlog 0b 0p requeues 0

So on transmit for eth0 (I believe) there were 90 million packets sent
and about 1.6 million (~1.6%) of them had to be requeued.

That continues to seem high.

---
I would agree, but I don't know what's acceptable.
requeues are ways to "slow" down traffic at a particular level
because that "level", priority or class of traffic has been too
busy.

I haven't changed out any cables, etc. yet.

They deteriorate over time, "sorta", If you have
a spare cable and adapter, might provide useful data to try.

That said, dropped packets can come from things other than
HW probs -- like timing probs (a burst came in when computer
was busy). Do you know how your kernel's preemption model
is set? (zgrep -i preempt /proc/config.gz).

Mostly looking at PREEMPT model:
None - no forced preemption (server)
voluntary kernel preemption (desktop)
preemptible kernel (low-latency desktop)

I wouldn't agree that servers should use 'none', depends
on what you are serving. You don't want a disk-backup
causing stutters when you are streaming video from
the server. But if you had a slowish disk or one that
was dying and needing retries, it might be possible it
was blocking handling bytes. Not real likely, but
possible...

Anyway... do you know what you have?






I didn't see in the prev discussion -- there was
alot of text to wade through, .



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