John Forte wrote: > I am sponsoring this fasttrack for Sumit Gupta. Requested binding is Patch, > timeout is 04/09/2008 > > - John > > > Template Version: @(#)sac_nextcase 1.64 07/13/07 SMI > This information is Copyright 2008 Sun Microsystems > 1. Introduction > 1.1. Project/Component Working Name: > SCSI Block Disk Provider for COMSTAR > 1.2. Name of Document Author/Supplier: > Author: Sumit Gupta > 1.3 Date of This Document: > 01 April, 2008 > 4. Technical Description > SCSI Block Disk Provider for COMSTAR > > > 1. Summary > > This command (sbdadm) and associated driver (sbd) will provide SCSI block disk > device support for COMSTAR (PSARC/2007/523). The command sbdadm(1M) will > provide support for creating logical units utilizing any file or raw block > device as the backing store. Logical units created with sbdadm will be > available to the COMSTAR framework and can be further managed and provisioned > to storage clients in the network using stmfadm(1M). Logical units created > with sbdadm(1M) are persistent across reboots. > > 2. Documentation > > NAME > sbdadm - SCSI Block Disk Command Line Interface > > SYNOPSIS > sbdadm create-lu [-s, --size <size>] <filename> > sbdadm delete-lu <lu_name> > sbdadm import-lu <lu_name> > sbdadm list-lu > sbdadm modify-lu [-s, --size <size>] <lu_name>|<filename> > > > DESCRIPTION > > The sbdadm command provides the ability to create SCSI disk type > Logical Units and register them with the SCSI Target Mode Framework > described by stmf(7D) so that they can be exposed outside of the > Solaris host to other initiators on the storage network. > > The SCSI Logical Unit thus created uses the specified file as its > backing store to store the logical unit data. The size of the > Logical Unit is derived from the size of the file minus 64K > to store the control information for the Logical Unit. The size > of the Logical unit can also be specified by the command line > option in which case it is possible to create Logical Units > without initially occupying any physical storage. The maximum > supported size for a Logical Unit is 8 Exabytes. > > filename Name of an existing file or a fully qualified path to a > raw block device. > > lu_name The 32-byte hexadecimal representation of the logical > unit. This is available in the output of "sbdadm create-lu" > or from "sbdadm list-lu". This 32-byte hexadecimal > representation will also be available using the > stmfadm(1M) > command. > > SUBCOMMANDS > sbdadm -? > > sbdadm create-lu [-s, --size <size>] <filename> > > Create a logical unit that can be registered with stmf(7D). > > -s, --size <size> > > <size> is an integer value which can be followed by > one of the following letters to indicate : > k kilobyte > m megabyte > g gigabyte > t terabyte > p petabyte > e exabyte > > If this option is not specified, <size> defaults to > the size of <filename>. > > The size specified may exceed the size of the file or > device. >
I'm just wondering if there's a piece of potentially useful functionality which is almost, but not quite here, and might be worthy of consideration? I'm thinking of a case where you have taken a copy of an existing disk which is to be retired in the form of a whole disk image (e.g. using dd(1)) into a file, and you want to reprovision this disk image file using iSCSI. It looks to me like I can't quite do that with the existing command set, i.e. bring in an existing raw disk image (not one created with the proposed create-lu subcommand). I could see this as a potentially useful feature during a server consolidation program, to be able to grab images of disks from the individual servers which are to be decommissioned and reprovision these file images from an iSCSI target server. This should go with a reverse function to export the raw disk image (i.e. strip off the 64k control information). If the control information was defined to be at the end of the file/media, in many cases, applications which expect to access disk images could use these files directly too. (Would also make adding and stripping it easy.) This could also be useful to work around the missing disk label support in lofi(7D). -- Andrew Gabriel
