CDUMP(8S)

NAME
cdump - standalone compress memory dumper

SYNOPSIS
From the powerup monitor:

on SCED-based systems:
* b 80 dv(un,su) stand/cdump dumpdev offset dynixname [ size ] [ -o ]

or

* b 80 dv(un,su) stand/cdump -f dumplist dynixname [ -o ]

on SSM-based systems:
---> bh '88 dv(un,su) stand/cdump dumpdev offset dynixname [ size ] [ -o ]'

or

---> bh '88 dv(un,su) stand/cdump -f dumplist dynixname [ -o ]'

DESCRIPTION
Cdump dumps a compressed image of memory. The compressed image is of a form which is readable by crash(8) "on-the-fly". Cdump writes the compressed image at offset blocks (specified as a decimal integer) past the beginning of device dumpdev (specified in standalone file notation; see boot(8S)). Dynixname should be the name of the same device as dumpdev expressed as a DYNIX file (usually beginning with /dev/).

The -f flag allows multiple dump devices to be specified. The dumplist file name must be specified in standalone notation, and dynixname should be the DYNIX equivalent of the standalone filename dumplist. Each line in the dumplist file has the format:

    dumpdev offset dynixname [ size ]

Each line of the file describes where a section of the dump will placed.

By default, all of memory is dumped, up to the size of the disk partition of a VTOC disk, or 16 Mbytes for a compatability disk, minus the offset. Other memory sizes (smaller or larger) may be specified with the size parameter, measured in 512-byte sectors (as a decimal integer). The value of size is rounded down to the nearest mutiple of 32 Kbytes. If the disk has a VTOC, the size of the disk partition will be used as a limit on the value of size. Dump sizes are treated as the space available on a device, for the compressed image, and not as the amount of memory to be saved on that device.

Cdump normally aborts if an attempt is made to overwrite an existing dump. If -o is specified, cdump will proceed with the dump even if a previous dump has not been cleared.

The wn1 powerup monitor command, or the n1= option of the bootflags(8) command, can be used to store a permanent dump invocation, so that DYNIX can automatically generate dumps. The standard /etc/rc.local already invokes bootflags to do this. A typical invocation of cdump looks like:

    b 80 sd(0,0)stand/cdump sd(0,1) 1000 /dev/sd0b

    or

    bh '88wd(0,0)stand/cdump wd(0,1) 1000 /dev/wd0b'

A typical use of cdump specifying multiple dump partitions looks like:

    b 80 sd(0,0)stand/cdump -f sd(0,0)etc/DUMPLIST /etc/DUMPLIST

An example of /etc/DUMPLIST looks like:

    sd(0,1) 1000 /dev/sd0b 33440
    sd(8,1) 0 /dev/sd1b 33440
    zd(0,1) 0 /dev/zd0b 67716

Note: An equivalent compressed image of the memory can also be obtained by taking a regular dump (Using dump), and then invoking savecore with the "-C" option. This is normally a faster method because savecore does compression in parallel. Cdump is slower but requires less swap space.

SEE ALSO
boot(8S), savecore(8), DYNIX System Administration Guide