Date: Thu, 15 Apr 1999 15:32:09 -0600 (MDT) From: "Kenneth D. Merry" <ken@plutotech.com> To: mjacob@feral.com Cc: freebsd-scsi@FreeBSD.ORG Subject: Re: I/O distributed across multiple SCSi busses, same hba... Message-ID: <199904152132.PAA04943@panzer.plutotech.com> In-Reply-To: <Pine.LNX.4.04.9904151409440.4563-100000@feral-gw> from Matthew Jacob at "Apr 15, 1999 2:12:20 pm"
next in thread | previous in thread | raw e-mail | index | archive | help
Matthew Jacob wrote...
>
> Here's a case of a two-channel Qlogic 1240 (two independent Ultra channels
> on the same controller card)- I'm doing lmdd's reading from a drive on
> either bus simultaneously. There's a very wierd distrbution of I/O from
> bus to bus. Anyone have a quick notion as to why? It's not a controller
> hw queue resource issue as this is raw access... it might be f/w but I'd
> kinda doubt it. Is it a VM thingie perhaps? I wouldna think so....
There's definitely something wrong here.
> tty da0 da1 cpu
> tin tout KB/t tps MB/s KB/t tps MB/s us ni sy in id
> 1 26 0.00 0 0.00 0.00 0 0.00 4 0 13 6 77
> 0 12 8.00 3 9.87 8.00 1262 9.86 2 0 68 20 11
> 0 12 8.00 5 9.80 8.00 1249 9.76 1 0 71 17 12
> 0 12 8.00 1255 9.80 8.00 1243 9.71 2 0 67 19 13
> 0 12 8.00 6 9.89 8.00 1265 9.88 2 0 70 18 10
> 0 12 8.00 1267 9.90 8.00 1258 9.83 3 0 68 18 11
> 0 12 8.00 263 9.87 8.00 1253 9.79 2 0 70 19 10
> 0 12 8.00 1265 9.88 8.00 1230 9.61 3 0 68 16 13
> 0 12 8.00 64 9.87 8.00 1240 9.69 3 0 65 18 14
> 0 12 8.00 1259 9.83 8.00 1236 9.66 2 0 66 22 10
> 0 12 8.00 263 9.87 8.00 1240 9.68 3 0 68 17 11
> 0 12 8.00 3 9.87 8.00 1239 9.68 2 0 68 19 11
> 0 12 8.00 1261 9.85 8.00 1239 9.68 2 0 66 21 11
> 0 12 8.00 1262 9.86 8.00 1239 9.68 2 0 71 17 11
> 0 12 8.00 7 9.90 8.00 1226 9.58 2 0 67 17 13
> 0 12 8.00 1261 9.86 8.00 1239 9.68 2 0 71 16 12
> 0 12 8.00 1259 9.83 8.00 1239 9.68 3 0 69 16 12
> 0 12 8.00 1251 9.77 8.00 1239 9.68 4 0 66 18 13
> 0 12 8.00 252 9.78 8.00 1239 9.68 2 0 67 19 13
> 0 12 8.00 1252 9.78 8.00 1219 9.52 3 0 65 19 13
> tty da0 da1 cpu
> tin tout KB/t tps MB/s KB/t tps MB/s us ni sy in id
> 0 36 8.00 1252 9.78 8.00 1214 9.48 3 0 65 17 14
This looks like some sort of printf-type bug. I think, in some of the
cases, you're only getting a few of the digits. Notice that the megabytes
per second is consistent all the way down. The transaction size is as
well.
But the transactions per second field varies widely. I think it may be
that some of the digits aren't getting shown. Like it'll only show the
last 1, 2, or 3 digits sometimes.
Obviously, (MB/sec * 1024) / KB/t == (or should equal) transfers per second.
Here's the relevant code from iostat(8). It's worked fine up until now. I
take it this is a -current box with egcs? Alpha or i386?
else {
total_mb = total_bytes;
total_mb /= 1024 * 1024;
printf(" %5.2Lf %3.1qu %5.2Lf ",
kb_per_transfer,
total_transfers,
total_mb);
}
Ken
--
Kenneth Merry
ken@plutotech.com
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-scsi" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199904152132.PAA04943>