Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!ut-emx!ibmchs!auschs!awdprime!aixwiz.austin.ibm.com!johnson From: johnson@aixwiz.austin.ibm.com (Fred L. Johnson) Newsgroups: comp.unix.aix Subject: Re: "rdump" only writes half as much data as "backup" Message-ID: <8445@awdprime.UUCP> Date: 13 Jun 91 15:04:32 GMT References: Sender: news@awdprime.UUCP Reply-To: johnson@aixwiz.austin.ibm.com (Fred L. Johnson) Organization: IBM Lines: 33 In article , henkel%nepjt@ncsuvx.ncsu.edu (Chuck Henkel) writes: ... > Context: Two RS/6000 Model 320s running 3001. > Tape drive configured for 512 byte blocks, no ECC > ... > And, why doesn't this work: > > backup -0 -b 126 -f - /u | rsh rs2 dd of=/dev/rmt0 obs=126 > > The dd dies immediately with "invalid argument to system call" or > somesuch. In fact, I can't get dd to write on the tape at all. The dd is dying because of the obs=126. This is telling dd to use 126 byte blocks for its write system call. The 1/4" tape only accepts i/o requests in multiples of 512 bytes, hence the EINVAL returned to dd from the write system call. Using 126b would tell dd to use a block size of 126, 512 byte blocks, and this should make the tape device driver happier. - Fred My remarks and opinions are mine alone... ____________________________________________________________________________ | | | | Fred L. Johnson | Internet: johnson@aixwiz.austin.ibm.com | | IBM Personal Systems Programming | inet: johnson@tanstaafl.austin.ibm.com | | AIX BOS Field Quality | vnet: FJOHNSON at AUSVMQ | | 11400 Burnet Road, 994/3401 | phone: (512) 823-4706 | | Austin, TX 78758-3493 | tie line: 793-4706 | |__________________________________|_________________________________________|