Presentation on theme: "CMS Formatter for Linux Virtual Software Systems, Inc. Session 9155 SHARE in Orlando - February 2008."— Presentation transcript:
CMS Formatter for Linux Virtual Software Systems, Inc. Session 9155 SHARE in Orlando - February 2008
CMS Formatter for Linux LXFMT is a CMS formatter to format 3390 disks for Linux use. LXFMT is a CMS-based utility for preparing minidisks intended to be used by Linux systems in virtual machines. It allows placing a Linux CDL format disk label and partition table on a minidisk from the CMS command line. It does not currently create a Linux filesystem but suppresses errors from the Linux boot process when a system is presented with a fresh minidisk.
LXFMT Distribution Files The files included in a VMARC distribution file are as follows: LXFMT ASSEMBLE – The assemble file for the formatter. LXFMT TEXT – The text output from an HLASM assembly. LXFMT MODUILE – The module file created from the above text file. LXFMT HELPCMS – LXFMT CMS help file. LXASM EXEC – An assembly exec that uses VMFHLASM to assemble LXFMT. LNXVM CNTRL – An assembly control file for the assembly. LXFMT README – The information in this presentation. LXVMARC EXEC – Exec to build the LXFMT VMARC file. LXFMT1 LXCONFIG – Configuration file to define partitions for ECKD disks.
LXFMT Command The format of the LXFMT command is: LXFMT vdev ( -B blksize -C filespec -F -K -M -N -S -TS -U -Y -P1 start end -P2 start end -P3 start end
LXFMT Command Parameters (1 of 4) vdev The virtual device number (address) of a disk to be formatted for use by Linux. Required. volser An optional volume serial to be used in the volume label. The default is 0Xvdev, where vdev is the virtual device number. blksize The size of the blocks (in bytes or K bytes) to use for the format. Choices are 4096, 2048, 1024, 512, 4K, 2K, 1K. Defaults to 4096 (4K) bytes.
LXFMT Command Parameters (2 of 4) -C filespec The file name and optionally the file type and mode for a config file containing starting and ending tracks for up to 3 partitions to create on a ECKD disk. The file type defaults to LXCONFIG. The format of the file is the same as the format for the FDASD Linux command. The words FIRST and LAST can be used for the first and last tracks on the disk. The following sample file would create 3 partitions: first, , ,last -F Format all tracks or blocks on the disk. If -F is not specified, only tracks 0 and 1 on ECKD and blocks 0-3 on FBA will be altered. If you do not specify the -F option for an ECKD disk that has never been formatted, you will not be able to write the label and VTOC with LXFMT. ECKD disks are formatted in CDL format and a z/OS format VTOC. FBA disks are formatted in CDL format and a DSO/VSE VTOC.
LXFMT Command Parameters (3 of 4) -K Keep existing volume serial. -M Show periodic format progress messages. A message will be issued after each 250 cylinders or 360,000 FBA blocks (45,000 4K blocks). If -M is not specified, you can determine the format progress by entering #CP EXT 41 on the CMS console at any time during the format for ECKD or zeroing for FBA. -N Do not create partitions. -S Shows a map of the current disk allocation.
LXFMT Command Parameters (4 of 4) -TS Creates a single swap type partition on the disk. -U Recreate label and VTOC tracks using existing partition sizes. -Y Format immediately without prompting for confirmation. -P1 start end Provides the starting and ending tracks for partition 1 for ECKD disk. -P2 start end Provides the starting and ending tracks for partition 2 for ECKD disk. -P3 start end Provides the starting and ending tracks for partition 3 for ECKD disk.
LXFMT Usage Notes (1 of 2) Partitions Partitions are validated to start above track 1 and be within the size of the disk. They are also check for overlaps. Gaps between partitions are allowed and not checked. Working with pre-formatted disks When you run LXFMT against an ECKD disk that is formatted, LXFMT will read a count field from track 2 and the last track to verify the format. If an I/O error occurs reading either count field, LXFMT will exit with an error message. If the block size in the two count fields is different, LXFMT will exit with an error message. If the block size from the count fields does not match the block size specified on the LXFMT command, you will be prompted to select which block size to use. If you select the block size entered on the command, the block size in the format 1 DSCB for the partitions will not match the format block size.
LXFMT Usage Notes (2 of 2) CMS Access After formatting an ECKD or FBA disk with LXFMT, it can be accessed as a CMS mode letter. The CMS LISTDC command with the FORMAT or EXTENT options can then be used to display VTOC information. If you run LXFMT against a disk that is already accessed by CMS, you must re-access the disk to see the changes with LISTDS.
LXFMT Sample Session Formatting a Mod-3 lxfmt 312b LXFMT - Linux disk formatter Version 2.1 assembled 01/02/ Format disk on 312B(0X312B)? Enter YES (1) or NO (0) 1 Formatting disk 312B(0X312B) CP EXT Blocks formatted on 312B(0X312B) 11% complete CP EXT Blocks formatted on 312B(0X312B) 40% complete Blocks formatted on 312B(0X312B) 100% complete LXFMT complete Ready; T=0.24/ :39:54
LXFMT License This software is available at no charge under the terms of the GNU General Public License version 3 (GPLv3) as available from the OSI (Open Source Initiative) website.
CMS Formatter for Linux Virtual Software Systems, Inc.