Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!rutgers!sri-spam!ames!ptsfa!dual!forbrk!mats From: mats@forbrk.UUCP (Mats Wichmann) Newsgroups: comp.unix.wizards Subject: Re: Size of SysV "block" Message-ID: <348@forbrk.UUCP> Date: Tue, 30-Jun-87 09:44:42 EDT Article-I.D.: forbrk.348 Posted: Tue Jun 30 09:44:42 1987 Date-Received: Sat, 11-Jul-87 01:43:08 EDT References: <218@astra.necisa.oz> Reply-To: mats@forbrk.UUCP (Mats Wichmann) Distribution: world Organization: Fortune Systems / SCI Technology (Berkeley, CA) Lines: 23 Keywords: blocks sectors In article <218@astra.necisa.oz> dave@astra.necisa.oz (Dave Horsfall) writes: >Can anyone tell me in an unambiguous manner just how many bytes >are in the following System V (2.?) "blocks"? > ls -s du df tar -b cpio -B mkfs fsck fsdb All of the preceding are 512 byte "blocks" and refer to "disk" blocks; it is left at 512 to avoid having to change things around on systems which support different logical block sizes on different file systems and just for general consistency (let's see, this is a Frozzboz 1000, the blocks must 875 bytes each, unlike the 1500, where they are 950 each...). > BUFSIZ This is the stdio buffer size and varies from system to system, although it seems to be 1024 for most V.2 implementations - should be the same size as the largest allowable file system logical block. Note that there are programs, such as CPIO, which take an argument (-B in the case of cpio) which seems to indicate that the block size is changed; really this sets the "blocking factor" - how many blocks to collect before doing the physical write/read. The number reported by cpio when it finishes is still in terms of 512-byte blocks. Mats Wichmann