Low level format an scsi disk device
scsiformat [-options...] device
Low level formats the SCSI device identified by the scsi disk or generic scsi device node device. You must be root to perform this operation. scsiformat will ask a simple question to get your confirmation and check if partitions on device are still mounted. Possible swap spaces on device are swapoff(8)'ed prior to formatting.
During formatting a file like /tmp/scsiformat.xx:xx:xx:xx:xxxxxxxx is used to hold some status information.
scsiformat supports the following option switches:
-b n
block during the format operation. This makes any display of real progress indicators impossible. However, cheesy SCSI devices will need it. Scsiformat assumes that the operation will need about n seconds and provides some progress indication according to that. -b0 does not print any process indication, just sits and blocks until formatting completes.
Read the BUGS section below!
-T
just check for a running format command and output statistics. A file /tmp/scsiformat.* is used to hold the starting time of the format operation. If formatting completed, this file is removed by the formatting scsiformat call (which forks of a child just for this purpose). The exit state of scsiformat is true as long as the format operation is still in progress. A left over /tmp/scsiformat.* file will make scsiformat think a program still runs. It will not accept and remove files older than 48h nevertheless.
-t n
check progress every n seconds (default is 5). -t0 makes scsiformat return without displaying progress.
-i n
sets the sector interleave factor to be used. Usually you should stick with the default -i0 which selects a vendor specific default.
By default the target will initialise the formatted sectors with a vendor specific test pattern.
-I sequence of bytes in hex
the bytes given in hex characters are repeated and used to init all blocks on the device.
-L
The first four bytes of each logical block are set to the number of the logical block.
-P
The first four bytes of each physical block are set to the number of logical block, it will occur in.
-e
Erase the grown defect list prior to formatting. You can issue new defects for the grown defect list nevertheless and media certification may add defects too.
-p
Ignore the vendor's primary defect list. This is not recommended as the vendor probably had a reason to specify these primary defects.
-c
Do not perform a media surface certification. This may speed up formatting but is also not recommended.
-s
Stop when unable to access primary or grown defects due to some internal error in the target device. When not given, formatting continues but returns a recovered error upon completion. (Which is probably not well supported by scsiformat).
-S
Erase MODE SELECT settings stored in NVRAM. These are those you can set with scsiinfo(8) or scsi-config(8).
-d int, ...
A comma separated list of logical blocks to mark as defect. Using this defect format is discouraged as there no clear concept of what a logical block is here because the format command may move around logical blocks and change the number of available blocks.
The number can be preceded by 0 or 0x for octal or hexadecimal notation.
-D int:int:int, ...
A comma separated list of expressions of the form C:H:S specifying a defect at physical location Cylinder:Head:Sector. A Sector S of -1 marks the whole track as bad.
The number can be preceded by 0 or 0x for octal or hexadecimal notation.
-B int:int:int, ...
A comma separated list of expressions of the from C:H:B specifying defects at Cylinder:Head:Bytes from Index. Again, a Bytes from Index value B of -1 marks the whole track as bad.
The number can be preceded by 0 or 0x for octal or hexadecimal notation.
You can specify more than one of the -d, -D, -B options but you must stick to one defect format!
For your convenience, scsiformat allow to preset the partition table in a simple way which often suffices for removable medias. This is not intended as a replacement for fdisk(8) though.
-f arg
perform simple partitioning. -fdos sets up begin and start of the partition on cylinder boundaries. -ftight does use as much of the disk as possible (but may confuse OS's other than Linux).
If you do not specify -f at all, scsiformat will not initialise the partition table. As it has to tell the kernel that the disk was reformatted and the kernel will try to to read the partition table, you are like to get some kernel warnings then.
-G headsxsectors
set the disk geometry (Heads x Sectors) as DOS will see it for use in the partition table. If you don't specify it, scsiformat will ask the kernel what it thinks DOS will get from the adapters BIOS. This call might fail or return bogus data though. A wrong setting will not affect linux, but other OS's and esp. DOS and the BIOS (for booting).
-y type
set the type for the partition to set. type is a two digit hex number. See fdisk(8),command t for a list. Defaults to 83 (Linux native).
-M size
Create a primary partition number 1 of maximal size sizeMB. When size is 0, no partition is created, and thus the partition table is simply initialised to be valid (but empty). If the size exceeds the disk capacity, a partition as large as possible is made. Defaults to 99999.
-H
print some command line help to stdout.
-v
print version information.
-F arg
forced operation, do not ask prior to format. arg must be 'Ene Mene Meck, und Du bist weg!' with proper spaces and capitalisation. (this is a German child rhyme kissing someone goodbye...)
-V
print some debugging information.
-X
all output is printed in numerics, useful for GUI interfaces like tk_scsiformat(8). Also makes all operations non blocking. (By forking of a child process for those scsi operations which would block).
-o
The settings of the flags -c, -p, -s, -S, -I, -L, -P are obeyed. If you specify one of these, -o is silently added. Without -o or one of these flags some factory default is used. Specifying -o explicitly will allow you to not use any of these options which might not be the default chosen by the target device otherwise.
Apart from the codes returned by the -T flag, scsiformat will generally return 1 for system errors, 2 for user errors, and 0 for successful operation.
Old status files in /tmp will confuse the -T option. However, they are removed after 48 hours.
I was unable to get hold of a disk supporting querying the progress status (and which I could stand to lose all data on). Therefore I commented out the support for this from the source code using a BLOCKING_ONLY#define. You are welcome to try and make this work.
Restrictions of the SCSI_IOCTL_SEND_COMMAND ioctl(2) call for the sd(4) device make it impossible to issue a FORMAT_UNIT command with more than 4096 bytes of arguments. This could be avoided by using the proper generic scsi device /dev/sg* instead, at least where the kernel is compiled to support it. Most of the time this is not needed though and thus I'm myself to lazy to do it.
/tmp/scsiformat.xx:xx:xx:xx:xxxxxxxx
/dev/sd*
/dev/sg*
tk_scsiformat(8), scsiinfo(8), scsi-config(8), fdisk(8), sd(4).
Michael Weller <[email protected]>