NetNews Usenet Archive 1992 #18/NN_1992_18.iso/spool/comp/sys/sgi/12416

Text File | 1992-08-14 | 1.9 KB | 43 lines

Newsgroups: comp.sys.sgi
Path: sparky!uunet!utcsri!torn!csd.unb.ca!morgan.ucs.mun.ca!agouldng
From: [e-mail] (Allan Goulding)
Subject: Re: Problem reading a tar file on exabyte
Message-ID: <[e-mail]>
Organization: Memorial University of Newfoundland
References: <[e-mail]> <[e-mail]>
Date: Fri, 14 Aug 1992 16:46:02 GMT
Lines: 32

In article <[e-mail]> [e-mail] (Dave Olson) writes:
>In <[e-mail]> [e-mail] (Allan Goulding) writes:
>| I am having a problem reading a tar file on an exabyte tape.
>| % tar xovqqbf 10240 /dev/exabnrnsv
>| myio(read): wanted 5242880 bytes, got -1
>|         errno is 12: Not enough spacetar: tape read error: Not enough space
>| exiting myio, firsttape 1
>| exiting from done, n 2
>
>Since for some reason tar doesn't seem to be figuring out
>the block size correctly, try specifying it explictly (10240
>is wrong, that is 10240*512, you want 20).

Thanks Dave, 20 is indeed the correct blocksize. The correct incantation is
  tar xovfb /dev/exabnrnsv 20

I'm guilty of assuming that the b argument to tar and bru are the same.
bru b is bytes by default, tar b is blocks. I also just noted in the tar man
page the caveat of the argument order, f before b. It is amazing how you
can still miss these little details after reading them so often.

BTW, mt -t /dev/exabnrnsv blksize says:
 Recommended tape I/O size: 131072 bytes (256 512-byte blocks)
 Minimum block size: 1 byte(s)
 Maximum block size: 245760 bytes
 Current block size: Variable

--
=============================================================================
Allan Goulding, Physical Oceanography group !    [e-mail]
Physics Dept., Memorial Univ. of Nfld.      ! or [e-mail]
St. John's, NF. Canada, A1B 3X7             !