mpd5/Netgraph issues after upgrading to 7.4

[Eugene Grosbein]

On 11.04.2011 03:45, Przemyslaw Frasunek wrote:
>> Use command "vmstat -z|egrep 'ITEM|NetGraph'" and check FAILURES column.
>> If you see non-zero values there, you need to increase netgraph memory limits
>> net.graph.maxdata and net.graph.maxalloc using /boot/loader.conf.
> 
> Thanks, indeed it helped a lot. I also noticed that other zones have
> non-zero failure counters:
> 
> UMA Slabs:                 64,        0,     2666,     1051,   128676,
>     127
> 128 Bucket:               524,        0,     1455,      316,    82489,
> 97401821
> g_bio:                    132,        0,        0,     3190, 11471737,
>       3
> ata_request:              192,        0,        0,     1880,  2905852,
>     378
> rtentry:                  124,        0,     2513,     1765,   802803,
>     132
> pffrent:                   16,     5075,      175,     3073, 48983719,
>       6
> pffrag:                    48,        0,       39,     3081, 15699916,
>     216
> 
> I'm quite anxious about "ata_request" failures.

In general, you should not worry about failures here - they are transient and normal.

Afaik, that's only mpd that cannot gracefully recover from such errors (it should).
So, increasing mentioned tunnables is only workaround from mpd's deficiency.

Eugene Grosbein