name Iago Iago is the Cedar disk formatting and maintenance program. It provides commands to prepare disks for operation in a Cedar system, to describe the machine on which it is running, and to effect some simple repairs when things break. Iago can be invoked in two ways: by net booting Cedar or by booting Cedar with the 'l switch and answering 'y to the question "Do you want to use Iago?". Once in Iago, it is only necessary to type a unique prefix followed by a separator, such as blank or carriage-return, to invoke any of the following commands. Many of the commands have their own prompters. Any time the program is expecting keyboard input, DEL will return you to the top level command interpreter. This is not an interrupt: it won't stop a long running command such as format. ExtraIago.df: more tools for finding and fixing disk problems. Includes ExtraIagoDoc.tioga. DiskErrorRecovery.tioga: instructions for using Iago and ExtraIago tools to repair some common disk problems. ¬IagoDoc.Tioga Copyright c 1985 by Xerox Corporation. All rights reserved. Carl Hauser, November 19, 1985 10:04:57 am PST Description Bare Machine Commands Describe Machine Provides info about the processor: serial number, Ethernet address, physical memory Describe Drives Provides info about on-line drives: drive numbers and size in pages of each one Login user provides new user name and password for use by ensuing commands Reserve Alto Regions allocates disk space for use by Alto emulation mode; this must be done before formatting and only pertains to Drive 0 (RD0). Format Disk prepares a disk for further use by the system. Writes a header on each sector of the disk for use by the disk hardware. Writes a random bit pattern in each sector, and verifies it is readable. May make a specifiable number of additional passes writing other random bit patterns and reading them back. At the end, a bad page table is created, and any bad pages that have been discovered are stored in it. Run Diagnostic BCD runs another program and attaches its commands to the list provided by Iago. The default program is ExtraIago. Install Credentials Aks you "Do you want to password-protect this disk?". A 'y answer makes the machine usable only by the currently logged-in user via normal booting. A 'n answer makes the machine available to anyone with Grapevine credentials. Beware: when password-protected a machine is still accessible using net booting. Check Drive scans a disk looking for hard and soft disk errors. At the end, any sectors with hard errors are added to the bad page table. Commands Manipulating Physical and Logical Volumes Create Physical Volume builds data structures representing an entire disk (except Alto regions). Create Logical Volume builds data structures representing an independently named logical volume on a physical volume. A physical volume may contain many logical volumes. As each is created, you are prompted for its size. Describe Logical Volumes, Describe Physical Volumes lists all information about all logical or physical volumes Erase Logical Volume prepares a logical volume for use by File. Writes a label on each sector of the logical volume and builds the Volume Allocation Map (VAM). The label is a free page label, except for a few root files such as the VAM. RecomputeVAM scans a logical volume and ensures that the VAM and the sector labels agree about which sectors are allocated and which are free. The truth is in the labels, and the VAM is made consistent with them. Commands Manipulating FS file systems Attach File, Copy File, Delete Files, Flush Cache, List Cache, List File Info, List Names, Rename, Set Keep just what you would expect Scavenge recreate the FS BTree and VAM of an FS volume. Uses existing BTree, file headers, and sector labels to put an FS file system back together after a semi-catastrophe. By definition a semi-catastrophe is one that Scavenge will fix. If Scavenge can't fix it is a real catasrophe. Booting Commands Boot Logical Volume do a full boot of the installed boot file on a logical volume. Rollback Logical Volume boot using the checkpoint file on a logical volume. (This seems only to work for logical volumes on drive 0). Cedar System Volume manipulations Clear Pseudo Server, List Pseudo Server, Set Pseudo Server, Set Remote Names just what you would expectbut unlike the analogous commands performed in the commander, changes made from Iago are saved in ///RemoteNames.DontDeleteMe as soon as the command is performed, not deferred until a checkpoint is made. Cedar Installation Commands Install Boot File Copies a Cedar boot file, by default from a server, and makes it run as part of the boot sequence. This must be done whenever there is a new release of the boot file (usually whenever there is a new system release or "bounce"). Install Cedar Microcode, Install Germ, Install Initial Microcode Each of these commands copies the appropriate file, by default from a server, and makes it part of the booting sequence. These commands usually need to be done only once per Format of the drive involved. They variously pertain to a disk or a logical volume. Create VM Backing File Creates a file to be used when pages must be swapped out of real memory. Can be on any logical volume. Size should be at least 16000 pages and no more than 32000 pages. Set Physical Boot File, Set Physical Germ, Set Physical Microcode Sets pointers on the disk to these files used in booting. The Install commands do the right thing, so I've never had cause to use these commands. Create User World A macro command that will do all the work to install Cedar on a naked system. Its default values may be out of date these days, but it will tell you what it will do before it does it. This can be quite useful if you have to do the sequence yourself but don't remember it all. Use Create User World to remind you of the steps to be done, hit DEL to quit out of it, and then do them manually. Other Commands Set Working Directory Sets a local variable to the specified string for use in FS manipulations. Quit causes the boot that was interrupted by the "Do you want to use Iago?" question to proceed to the next step. See Also Contact Bob Carl Orr Κχ˜defaultšœ ™ Kšœ Οmœ1™™>—™N™m——š !™!™LN™ζ——š ™™N™δ—™@N™„—™N™ͺ—™AN™”—M™N™‹—š ™™N™J—™N™l——š ™M˜]Mšœo˜o—š ™MšœΟt™,——I pagebreak˜J˜—…—μ