barrett@jhunix.HCF.JHU.EDU (Dan Barrett) (07/16/90)
In article <5814@jhunix.HCF.JHU.EDU> I wrote: > I attempted to use rdump to backup our VAX 8530 (Ultrix 2.0) >onto the tape drive (TU81+) on our DECsystem 5400 (Ultrix 3.1d). > > DUMP: Protocol to remote tape server botched (code @?). > Lost connection to remote host. A few more points to follow-up my original posting: o Yes, I know about the "o" compatibility switch for rdump and rrestore. It doesn't work when dumping from a 2.0 machine to a 3.1 machine, as far as I can tell. (I assume it works the other way around.) 2.0 has no "o" switch at all. o I did manage to back up our VAX by doing: On VAX: rdump 0uf server:/tmp/root.dump / On DS5400: dd if=/tmp/root.dump of=/dev/rmt1h bs=10k Not ideal, but it works. (But I cannot rrestore from the tape drive anyway... gotta go back to disk first, then rrestore from the file.) :-( Still flailing... Dan //////////////////////////////////////\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ | Dan Barrett, Department of Computer Science Johns Hopkins University | | INTERNET: barrett@cs.jhu.edu | | | COMPUSERVE: >internet:barrett@cs.jhu.edu | UUCP: barrett@jhunix.UUCP | \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\/////////////////////////////////////
D. Allen [CGL]) (07/16/90)
Some timings you might be interested in.
Ultrix dump of root to nowhere:
bandicoot# time dump 0f - / >/dev/null
[dump stuff deleted]
16% real=0:22 usr=0.9 sys=2.7 rd=8 wr=4 mem=332 pg=0 rec=0 sw=0
sig=0 cs=959
BSD dump of root to nowhere:
bandicoot# /software/dumpster/maintenance/dump 0f - / >/dev/null
[dump stuff deleted]
6% real=0:31 usr=1.0 sys=1.2 rd=10 wr=14 mem=252 pg=10 rec=46 sw=0
sig=0 cs=582
Ultrix rdump of root to nowhere:
bandicoot# time /bin/rdump -0f bandicoot:/dev/null /
[dump stuff deleted]
39% real=0:55 usr=2.8 sys=19.1 rd=2 wr=6 mem=282 pg=3 rec=60 sw=0
sig=0 cs=4533
BSD rdump of root to nowhere:
bandicoot# time /software/dumpster/maintenance/rdump
-0f bandicoot:/dev/null /
[dump stuff deleted]
33% real=0:39 usr=1.9 sys=11.2 rd=10 wr=17 mem=283 pg=12 rec=64 sw=0
sig=0 cs=5002
Ultrix rdump of root to a real tape:
bandicoot# time rdump -0f recorder:/dev/nrmt0h /
[dump stuff deleted]
[I hit break after 6 minutes when dump estimated the dump
would take another 20 minutes]
BSD rdump of root to a real tape:
bandicoot# time /software/dumpster/maintenance/rdump
-0f recorder:/dev/nrmt0h /
[dump stuff deleted]
[I hit break after 7 minutes when dump estimated the dump
would take another 13 minutes]
Ultrix dump of root to rsh/dd to a tape:
bandicoot# time dump 0f - / | rsh rec dd bs=32k rbuf=2 wbuf=2 of=/dev/rmt0h
[dump stuff deleted]
7% real=1:31 usr=1.0 sys=6.0 rd=2 wr=4 mem=351 pg=0 rec=3 sw=0
sig=0 cs=4900
15% real=2:48 usr=2.5 sys=24.1 rd=15 wr=7 mem=206 pg=0 rec=3
sw=0 sig=0 cs=10300
BSD dump of root to rsh/dd to a tape:
bandicoot# time /software/dumpster/maintenance/dump 0f - /
| rsh rec dd bs=32k rbuf=2 wbuf=2 of=/dev/rmt0h
[dump stuff deleted]
2% real=1:31 usr=1.0 sys=1.1 rd=5 wr=16 mem=216 pg=2 rec=54 sw=0
sig=0 cs=534
13% real=2:53 usr=2.7 sys=20.7 rd=11 wr=16 mem=159 pg=2 rec=54
sw=0 sig=0 cs=6983
What I learned:
Don't use rdump. It's an order of magnitude slower than a pipe to dd.
In fact, even dump is slower than dump to stdout piped into dd with
wbuf=2, because of bugs in the Ultrix nbuf code. At least Ultrix dd
handles multiple tapes and multi-buffer writes; isn't that convenient?
--
-IAN! (Ian! D. Allen) idallen@watcgl.uwaterloo.ca idallen@watcgl.waterloo.edu
[129.97.128.64] Computer Graphics Lab/University of Waterloo/Ontario/Canada