setblocksize

Overview

This is a tool to reformat a SCSI disk with new block size.

You need such a tool if you want to use a disk from an IBM machine that uses 520Byte/block or 524Byte/block for a standard PC. setblocksize reformats the disk to a blocksize of 512Byte (which can be handled by any PC OS) or any other supported size smaller than 64KiByte that is supported by the disk.

setblocksize requires GNU/Linux with sg driver installed - connect the disk to a machine running this OS to reformat it.

Description

There are two ways to change the blocksize of a SCSI disk: Changing the blocksize parameter on the Format page (03h) or sending a blockdescriptor with the new blocksize. All disks that I have seen cannot handle different sizes of their logical blocks on a high level ('on the fly'). They need to low-level reformat their media to change the blocksize. Many disks do not allow you to change the format page blocksize parameter directly. Therefore setblocksize use the second method (the blockdescriptor). setblocksize send the following SCSI commands to the disk:

• MODE SELECT with a blockdescriptor that contains the specified blocksize
• FORMAT UNIT

Now the format page should show the new blocksize.

This tool can be used for all Seagate disks that support different block sizes. I got reports that it work for IBM disks too. Recently I got a success report for FibreChannel disks.

Download:

setblocksize V0.0 (bzip2 compressed tar archive) [Size: 45KiByte]
setblocksize V0.1 (bzip2 compressed tar archive) [Size: 46KiByte]
setblocksize V0.2 (bzip2 compressed tar archive) [Size: 46KiByte]

Changelog:

V0.0

• First released version.
• Formatting is started immedeately.

V0.1

• Controlling host adapter, SCSI channel, ID, LUN, manufacturer, model and type of the selected SCSI device are printed and must be confirmed before data is lost.
• The 'FORMAT UNIT' command is only supported by SCSI devices of type 0 (Direct access / Disk) or 7 (Optical disk). If a device with other type is specified, the program aborts.
• LUN constant of former version was ignored by sg driver because LUN is already selected via sg device => LUN constant removed.
• Tested to work with Linux 2.2 and 2.4.

V0.2

• Blocksize and Timeout can now be specified on the command line.
• Tested to work with Linux 2.6.