makedumpfile -v (return code: 0)
makedumpfile: version 1.6.1 (released on 27 Dec 2016) lzo enabled snappy disabled
makedumpfile --help (return code: 0)
LZO support: enabled snappy support: disabled ('-p' option will be ignored.) Usage: Creating DUMPFILE: # makedumpfile [-c|-l|-p|-E] [-d DL] [-e] [-x VMLINUX|-i VMCOREINFO] VMCORE DUMPFILE Creating DUMPFILE with filtered kernel data specified through filter config file or eppic macro: # makedumpfile [-c|-l|-p|-E] [-d DL] -x VMLINUX [--config FILTERCONFIGFILE] [--eppic EPPICMACRO] VMCORE DUMPFILE Outputting the dump data in the flattened format to the standard output: # makedumpfile -F [-c|-l|-p|-E] [-d DL] [-x VMLINUX|-i VMCOREINFO] VMCORE Rearranging the dump data in the flattened format to a readable DUMPFILE: # makedumpfile -R DUMPFILE Split the dump data to multiple DUMPFILEs in parallel: # makedumpfile --split [OPTION] [-x VMLINUX|-i VMCOREINFO] VMCORE DUMPFILE1 DUMPFILE2 [DUMPFILE3 ..] Using multiple threads to create DUMPFILE in parallel: # makedumpfile [OPTION] [-x VMLINUX|-i VMCOREINFO] --num-threads THREADNUM VMCORE DUMPFILE1 Reassemble multiple DUMPFILEs: # makedumpfile --reassemble DUMPFILE1 DUMPFILE2 [DUMPFILE3 ..] DUMPFILE Generating VMCOREINFO: # makedumpfile -g VMCOREINFO -x VMLINUX Extracting the dmesg log from a VMCORE: # makedumpfile --dump-dmesg [-x VMLINUX|-i VMCOREINFO] VMCORE LOGFILE Creating DUMPFILE of Xen: # makedumpfile [-c|-l|-p|-E] [--xen-syms XEN-SYMS|--xen-vmcoreinfo VMCOREINFO] VMCORE DUMPFILE Filtering domain-0 of Xen: # makedumpfile [-c|-l|-p|-E] -d DL -x vmlinux VMCORE DUMPFILE Generating VMCOREINFO of Xen: # makedumpfile -g VMCOREINFO --xen-syms XEN-SYMS Creating DUMPFILE from multiple VMCOREs generated on sadump diskset configuration: # makedumpfile [-c|-l|-p] [-d DL] -x VMLINUX --diskset=VMCORE1 --diskset=VMCORE2 [--diskset=VMCORE3 ..] DUMPFILE Available options: [-c|-l|-p]: Compress dump data by each page using zlib for -c option, lzo for -l option or snappy for -p option. A user cannot specify either of these options with -E option, because the ELF format does not support compressed data. THIS IS ONLY FOR THE CRASH UTILITY. [-e]: Exclude the page structures (vmemmap) which represent excluded pages. This greatly shortens the dump of a very large memory system. The --work-dir option must also be specified, as it will be used to hold bitmaps and a file of page numbers that are to be excluded. The -e option will cause a noncyclic dump procedure. This option is only for x86_64. [-d DL]: Specify the type of unnecessary page for analysis. Pages of the specified type are not copied to DUMPFILE. The page type marked in the following table is excluded. A user can specify multiple page types by setting the sum of each page type for Dump_Level (DL). The maximum of Dump_Level is 31. Note that Dump_Level for Xen dump filtering is 0 or 1 except on x86_64 | non- Dump | zero private private user free Level | page cache cache data page -------+--------------------------------------- 0 | 1 | X 2 | X 4 | X X 8 | X 16 | X 31 | X X X X X [-E]: Create DUMPFILE in the ELF format. This option cannot be specified with the -c, -l or -p options, because the ELF format does not support compressed data. [-x VMLINUX]: Specify the first kernel's VMLINUX to analyze the first kernel's memory usage. The page size of the first kernel and the second kernel should match. [-i VMCOREINFO]: Specify VMCOREINFO instead of VMLINUX for analyzing the first kernel's memory usage. VMCOREINFO should be made beforehand by makedumpfile with -g option, and it contains the first kernel's information. This option is necessary if VMCORE does not contain VMCOREINFO, [-x VMLINUX] is not specified, and dump_level is 2 or more. [-g VMCOREINFO]: Generate VMCOREINFO from the first kernel's VMLINUX. VMCOREINFO must be generated on the system that is running the first kernel. With -i option, a user can specify VMCOREINFO generated on the other system that is running the same first kernel. [-x VMLINUX] must be specified. [--config FILTERCONFIGFILE]: Used in conjunction with -x VMLINUX option, to specify the filter config file that contains filter commands to filter out desired kernel data from vmcore while creating DUMPFILE. [--eppic EPPICMACRO]: Used in conjunction with -x VMLINUX option, to specify the eppic macro file that contains filter rules or directory that contains eppic macro files to filter out desired kernel data from vmcore while creating DUMPFILE. When directory is specified, all the eppic macros in the directory are processed [-F]: Output the dump data in the flattened format to the standard output for transporting the dump data by SSH. Analysis tools cannot read the flattened format directly. For analysis, the dump data in the flattened format should be rearranged to a readable DUMPFILE by -R option. [-R]: Rearrange the dump data in the flattened format from the standard input to a readable DUMPFILE. [--split]: Split the dump data to multiple DUMPFILEs in parallel. If specifying DUMPFILEs on different storage devices, a device can share I/O load with other devices and it reduces time for saving the dump data. The file size of each DUMPFILE is smaller than the system memory size which is divided by the number of DUMPFILEs. This feature supports only the kdump-compressed format. [--num-threads THREADNUM]: Using multiple threads to read and compress data of each page in parallel. And it will reduces time for saving DUMPFILE. Note that if the usable cpu number is less than the thread number, it may lead to great performance degradation. This feature only supports creating DUMPFILE in kdump-comressed format from VMCORE in kdump-compressed format or elf format. [--reassemble]: Reassemble multiple DUMPFILEs, which are created by --split option, into one DUMPFILE. dumpfile1 and dumpfile2 are reassembled into dumpfile. [-b <order>] Specify the cache 2^order pages in ram when generating DUMPFILE before writing to output. The default value is 4. [--cyclic-buffer BUFFER_SIZE]: Specify the buffer size in kilo bytes for bitmap data. Filtering processing will be divided into multi cycles to fix the memory consumption, the number of cycles is represented as: num_of_cycles = system_memory / (BUFFER_SIZE * 1024 * bit_per_bytes * page_size) The lesser number of cycles, the faster working speed is expected. By default, BUFFER_SIZE will be calculated automatically depending on system memory size, so ordinary users don't need to specify this option. [--splitblock-size SPLITBLOCK_SIZE]: Specify the splitblock size in kilo bytes for analysis with --split. If --splitblock N is specified, difference of each splitted dumpfile size is at most N kilo bytes. [--work-dir]: Specify the working directory for the temporary bitmap file. If this option isn't specified, the bitmap will be saved on memory. Filtering processing has to do 2 pass scanning to fix the memory consumption, but it can be avoided by using working directory on file system. So if you specify this option, the filtering speed may be bit faster. [--non-mmap]: Never use mmap(2) to read VMCORE even if it supports mmap(2). Generally, reading VMCORE with mmap(2) is faster than without it, so ordinary users don't need to specify this option. This option is mainly for debugging. [--xen-syms XEN-SYMS]: Specify the XEN-SYMS to analyze Xen's memory usage. [--xen-vmcoreinfo VMCOREINFO]: Specify the VMCOREINFO of Xen to analyze Xen's memory usage. [--xen_phys_start XEN_PHYS_START_ADDRESS]: This option is only for x86_64. Specify the XEN_PHYS_START_ADDRESS, if the xen code/data is relocatable and VMCORE does not contain XEN_PHYS_START_ADDRESS in the CRASHINFO. [-X]: Exclude all the user domain pages from Xen kdump's VMCORE, and extract the part of Xen and domain-0. [--diskset=VMCORE]: Specify multiple VMCOREs created on sadump diskset configuration the same number of times as the number of VMCOREs in increasing order from left to right. [--message-level ML]: Specify the message types. Users can restrict output printed by specifying Message_Level (ML) with this option. The message type marked with an X in the following table is printed. For example, according to the table, specifying 7 as ML means progress indicator, common message, and error message are printed, and this is a default value. Note that the maximum value of message_level is 31. Message | progress common error debug report Level | indicator message message message message ---------+------------------------------------------------------ 0 | 1 | X 2 | X 4 | X * 7 | X X X 8 | X 16 | X 31 | X X X X X [--vtop VIRTUAL_ADDRESS]: This option is useful, when user debugs the translation problem of virtual address. If specifing the VIRTUAL_ADDRESS, its physical address is printed. [--dump-dmesg]: This option overrides the normal behavior of makedumpfile. Instead of compressing and filtering a VMCORE to make it smaller, it simply extracts the dmesg log from a VMCORE and writes it to the specified LOGFILE. If a VMCORE does not contain VMCOREINFO for dmesg, it is necessary to specfiy [-x VMLINUX] or [-i VMCOREINFO]. [--mem-usage]: This option is only for x86_64. This option is used to show the page numbers of current system in different use. It should be executed in 1st kernel. By the help of this, user can know how many pages is dumpable when different dump_level is specified. It analyzes the 'System Ram' and 'kernel text' program segment of /proc/kcore excluding the crashkernel range, then calculates the page number of different kind per vmcoreinfo. So currently /proc/kcore need be specified explicitly. [-D]: Print debugging message. [-f]: Overwrite DUMPFILE even if it already exists. [-h, --help]: Show help message and LZO/snappy support status (enabled/disabled). [-v]: Show the version of makedumpfile. VMLINUX: This is a pathname to the first kernel's vmlinux. This file must have the debug information of the first kernel to analyze the first kernel's memory usage. VMCORE: This is a pathname to the first kernel's memory core image. This argument is generally /proc/vmcore. DUMPFILE: This is a pathname to a file created by this command. XEN-SYMS: This is a pathname to the xen-syms. This file must have the debug information of Xen to analyze Xen's memory usage.