Subject: Serious problem with pax-as-tar: can't restore old big-record backups.
To: None <>
From: Thor Lancelot Simon <>
List: tech-userlevel
Date: 05/24/2003 15:59:35
With GNU tar as the system "tar" , I did backups with "-b 128", which
resulted in a 64K record size on tape.  Our new pax-as-tar accepts
-b 128 on the command line but will never use a buffer larger than 32256
bytes, which results in the kernel being unable to deliver full tape
records to tar, which results in a stream of error messages from at
least some host adapter drivers ("65536-byte tape record too large for
32256-byte user buffer") and unreadable backups.

I understand that ANSI tar allows a maximum blocksize of 32256 -- I
don't understand *why*, but I do understand that that's the standard.

However, it's a serious regression in functionality to not support
larger blocksizes on _read_, leaving people unable to restore old

 Thor Lancelot Simon	                            
   But as he knew no bad language, he had called him all the names of common
 objects that he could think of, and had screamed: "You lamp!  You towel!  You
 plate!" and so on.              --Sigmund Freud