NAME¶
zgetdump - Tool for copying and converting System z dumps
SYNOPSIS¶
zgetdump [OPTIONS] [DUMP/DUMPDEV] [DIR]
DESCRIPTION¶
The
zgetdump tool reads or converts a dump. The dump can be located
either on a dump device or on a file system. By default the dump content is
written to standard output, which you can redirect to a specific file. You can
also mount the dump content, print dump information, or check whether a DASD
device contains a valid dump tool.
OPTIONS¶
- -h or --help
- Print usage information, then exit.
- -v or --version
- Print version information, then exit.
- -m <DUMP> <DIR> or --mount
<DUMP> <DIR>
- Mount the DUMP to mount point DIR and generate a virtual
target dump file instead of writing the content to standard output. The
virtual dump file gets the name "dump.FMT", where FMT is the
name of the specified dump format (see "--fmt" option).
- -u <DIR> or --umount <DIR>
- Unmount the dump that is mounted at mount point DIR. This
option is a wrapper for "fusermount -u". Instead of DIR also the
the DUMP (e.g. /dev/dasdd1) can be specified.
- -d <DUMPDEV> or --device
<DUMPDEV>
- Check DASD device DUMPDEV for valid dump tool and print
information about it.
- -i <DUMP> or --info <DUMP>
- Print the dump header information reading from the DUMP and
check if the dump is valid. See chapter DUMP INFORMATION below for more
information.
- -f <FMT> or --fmt <FMT>
- Use the specified target dump format FMT when writing or
mounting the dump. The following target dump formats are supported:
- elf: Executable and Linking Format core dump (64 bit only)
- s390: s390 dump (default)
- DUMP
- This parameter specifies the file, partition or tape device
node where the dump is located:
- - Regular dump file (e.g. /testdir/dump.0)
- - DASD partition device node (e.g. /dev/dasdc1)
- - DASD device node for multi-volume dump (e.g.
/dev/dasdc)
- - Tape device node (e.g. /dev/ntibm0)
Note: For DASD multi-volume dump it is sufficient to specify only one of the
multi-volume DASD partitions as DUMP.
- DUMPDEV
- When using the "--device" option, DUMPDEV must be
the DASD device node of the dump disk that should be verified.
COPY DUMP¶
The default action of zgetdump is to copy the DUMP to standard output. Read the
examples section below for more information.
MOUNT DUMP¶
Instead of writing the dump content to standard output you can also mount the
dump using the "--mount" option. With that option it is possible to
convert the dump without the need of copying it. The zgetdump tool generates a
virtual target dump file that contains the dump in the requested target
format. The virtual dump file is generated by mounting the source dump as a
user space file system to the directory specified by the "--mount"
option. The virtual target dump file is called dump.<FMT> where FMT
denotes the format of the target dump. The virtual dump file exists as long as
the directory containing the file is not unmounted.
Mounting can be useful when you want to process the dump with a tool that cannot
read the original dump format. To do this, mount the dump and specify the
required target dump format with the "--fmt" option. Mounting is
also for useful for multi-volume DASD dumps. After a multi-volume dump has
been mounted, it is shown as a single dump file that can be accessed directly
with dump processing tools like "makedumpfile", "crash" or
"lcrash".
Mounting is implemented with "fuse" (file system in user space).
Therefore the "fuse" kernel module must to be loaded on the system
before the "--mount" option can be used.
A DASD dump can be mounted e.g. with "zgetdump /dev/dasdd1 -m /mnt"
and unmounted with either "zgetdump -u /mnt", "fusermount -u
/mnt" or "umount /mnt" (root only).
zgetdump supports the following dump formats:
- s390
- This dump format is System z specific and is used for DASD
and tape dumps.
- elf
- Executable and Linking Format core dump. This dump format
is also used for Linux user space core dumps. The zgetdump tool supports
this dump format only for 64 bit.
- lkcd
- This dump format has been used by the Linux Kernel Crash
Dumps (LKCD) project and is used on System z for the vmconvert and zfcp
(SCSI) dump tool. The zgetdump tool supports "lkcd" only as
source format.
- The default target format of zgetdump is "s390".
Use the "--fmt" option to change the target format.
-
When calling zgetdump with the "--info" option depending on the dump
format the following dump attributes are available:
- Dump format
- Name of the dump format.
- Version
- Version number of the dump format.
- Dump created/ended
- Time when the dump process was started or ended. The dump
time information is printed in your local time zone. E.g. "Wed, 03
Feb 2010 10:47:37 +0100" shows the time at your location. The meaning
of "+0100" is that your time zone is one hour behind GMT
(Greenwich Mean Time). You can use the "TZ" environment variable
or use the "tzselect" tool to change the time zone. For example,
if you know that the dump has been created in Hawaii, you can get the
correct time information with:
# TZ='Pacific/Honolulu' zgetdump -i DUMP
- Dump CPU ID
- Identifier of the CPU that executed the dump tool.
- Build arch
- Architecture (s390 or s390x) on which the dump tool was
built.
- System arch
- Architecture (s390 or s390x) of the dumped Linux
system.
- CPU count (online)
- Number of online CPUs.
- CPU count (real)
- Number of total CPUs (online and offline).
- Dump memory range
- Memory range that was dumped. This value is the difference
between the last dumped and the first dumped memory address.
- Real memory range
- Memory range that was available on system. This value is
the difference between the last and the first memory address of the dumped
system. The "real memory range" can differ from the "dump
memory range" when the SIZE parameter was used when preparing the
dump device with the zipl tool (see man zipl).
- Memory map
- Available memory chunks in the dump. Depending on the dump
tool there can be multiple memory chunks, when a system with memory holes
is dumped.
When calling zgetdump with the "--device" option depending on the dump
tool the following attributes are available:
- Dump tool
- Name of the dump tool.
- Version
- Version of the dump tool.
- Architecture
- Architecture (s390 or s390x) of the dump tool.
- DASD type
- Type of the DASD where the dump tool is installed (ECKD or
FBA).
- Dump size limit
- If this attribute is set, the dump tool will dump memory
only up to that limit even if there is more memory available.
- Force specified
- If that attribute is set to "yes", the
multi-volume DASD dump tool will not verify the dump signature on dump
partitions. This can be useful, if the dump partition is also used for
swap.
EXAMPLES¶
- Copy single volume DASD dump
-
The DASD partition /dev/dasdx1 was prepared for dump with:
# zipl -d /dev/dasdx1
The corresponding single-volume dump tool was IPLed. The respective zgetdump
call to copy the dump from the DASD partition to file dump.s390 is:
# zgetdump /dev/dasdx1 > dump.s390
- Copy multi-volume DASD dump
-
DASD partitions /dev/dasdx1 and /dev/dasdy1 contained in file dev_list.conf
were prepared for multi-volume dump with:
# zipl -M dev_list.conf
The corresponding multi-volume dump tool was IPLed. The respective zgetdump
call to copy the dump from the DASD partitions to file dump.s390 is:
# zgetdump /dev/dasdx > dump.s390
- Copy tape dump
-
Tape device /dev/ntibm0 was prepared with:
# zipl -d /dev/ntibm0
The corresponding tape dump tool was IPLed. The respective zgetdump call to
copy the dump from the tape to file dump.s390 is:
# zgetdump /dev/ntibm0 > dump.s390
- Using pipes for network transfer
-
You can redirect standard output to tools like ftp or ssh in order to
transfer the dump over the network without copying it into the file system
first.
Copy DASD dump using ssh:
# zgetdump /dev/dasdd1 | ssh user@host "cat > dump.s390"
Copy and compress DASD dump using ftp and gzip (note that not all ftp
clients can do this):
# ftp host
ftp> put |"zgetdump /dev/dasdd1 | gzip" dump.s390.gz
The same effect can also be achieved by using the "--mount" option
and run scp or ftp directly on the mounted virtual dump file.
- Using the --mount option
-
Mount multi-volume DASD dump, process it with the "crash" tool and
unmout it with zgetdump afterwards.
# zgetdump -m -f elf /dev/dasdx /dumps
# crash vmlinux /dumps/dump.elf
# zgetdump -u /dumps
Convert an ELF dump to an s390 dump by mounting it with the
"--fmt" option, process it with lcrash and unmount it with
fusermount afterwards.
# zgetdump -m -f s390 dump.elf /dumps
# lcrash System.map /dumps/dump.s390 Kerntypes
# fusermount -u /dumps
- Print dump information (--info)
-
Print information on DASD dump on /dev/dasdd1:
# zgetdump -i /dev/dasdd1
- Print DASD dump tool information (--device)
-
Print information on DASD dump tool on /dev/dasdd:
# zgetdump -d /dev/dasdd
SEE ALSO¶
zipl(8),
crash(8),
lcrash(8),
dumpconf(8),
vmconvert(8),
vmur(8)
