Messages in this thread | | | Date | Fri, 18 Sep 1998 10:36:46 -0400 (EDT) | From | David Mansfield <> | Subject | aha152x in 2.1.121 causes dropped ppp packets |
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Hello,
This an annoyance that I've seen since 2.0.3x that I decided to mention in case in can or should be fixed.
SUMMARY: aha152x with DAT combined with IDE activity (i.e. tar) blocks PPP. If I am accessing a SCSI-DAT drive (HP SureStore) via my aha152x card AND writing data to IDE disk, the system loses the ability to process serial port information.
Before the backup begins, ifconfig shows the following stats for ppp0:
ppp0 Link encap:Point-to-Point Protocol inet addr:x.x.x.z P-t-P:x.x.x.y Mask:255.255.255.255 UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1500 Metric:1 RX packets:11463 errors:0 dropped:0 overruns:0 frame:0 TX packets:7863 errors:0 dropped:0 overruns:0 carrier:0 collisions:0
Now. Let's say I have a nice big tar on sitting on the tape. If I do:
bash# tar -tvf /dev/nst0 >/dev/null 2>&1 &
No problems. However, if I simply change this to:
bash# tar -tvf /dev/nst0 >tar.log 2>&1 &
Most packets get dropped. Note that tar.log is being created on an old WD IDE hard drive. Pinging from the local machine causes the SD modem light to blink, the RD light blinks (about 100 ms later :-) and no ICMP reply shows up. About 2 in 10 get through. ifconfig now reports:
ppp0 Link encap:Point-to-Point Protocol inet addr:x.x.x.z P-t-P:x.x.x.y Mask:255.255.255.255 UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1500 Metric:1 RX packets:12076 errors:83 dropped:0 overruns:0 frame:83 TX packets:8309 errors:0 dropped:0 overruns:0 carrier:0 collisions:0
(note that there was some activity between these two ifconfig reports that occurred without the tape drive running, so I can't say exactly x out of y packets were dropped). Trying to access the other end of the link involves a 15-20 second latency for any data.
Bug or feature?
-- /==============================\ | David Mansfield | | david@cobite.com | | | | (212) 536-9115 | \==============================/
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