Re-Enabling Single User Mode :\

From what i understand, the booting up from single user mode (holding down Apple + S on boot up) has been disabled with firmware. This able to be removed by taking the battery out and removing a memory card. But i really don't want to do that.
My question is:
Is there any way to edit the sudoers file (or possibly execute the "visudo" command) using terminal? Or any other way *without administrative acces*.

Another way, though not as easy as the previous suggestion. would be to go
to the following download the appropriate ISO for you system. burn it to cdrom.
Then boot the system from the cdrom, it's will prompt about installing it. read the
notes that are printed to the screen. If memory serves me it, I believe you just need to
type 'shell' to get to a shell prompt, it's tells you in the notes. The mount the system disk and edit the file(s), disks device name are also reported.
http://www.opensource.apple.com/darwinsource/images/darwinppc-801.cdr.gz
http://www.opensource.apple.com/darwinsource/images/darwinx86-801.iso.gz
read the release notes. also, it will not install any software unless you tell it to.
http://www.opensource.apple.com/darwinsource/images/release-notes-8.0.1.txt
Message was edited by: Nils C. Anderson

Similar Messages

Can't enable root user in single user mode

hey, im having a problem. I cant enable the root user in single user mode. This is what I do:
1.boot in single user mode
2.I run the command /sbin/fsck -fy
3.I run the command /sbin/mount -uw /
4.I run the command passwd
5.I type the password and then I retype it, but it gives me an error saying passwd: cant change password for root the account is not enabled (thats not exactly what it said, but you get the point)
this worked in leopard, why dosent it work now? can someone give me an alternative way or tell me what im doing wrong?
P.S. give me an actual answer not a why enable root? and I dont want to use directory utility.

The command is wrong man. Do the following:
Boot into S.U. Mode (Cmd+S).
once the terminal prompt opens, type the following:
mount -uw / ("mount"+space+"-uw"+space+slash)
launchctl load /System/Library/LaunchDaemons/com.apple.opendirectoryd.plist
passwd root
(after you press enter it will ask the password for the root user. Type it, even if it won't show any character. Then type again to confirm. Once you had finished type: exit).
Test it and post the results.

Enable Remote Management in Single-User Mode

Hi,
I would like to know how to enable Remote Management option (System Preferences > Sharing) in single-user mode.
Thanks in advance
Regards

If ssh won't get you where you want and brute-force loading the various plists isn't working for your case (as mentioned, error messages and details might help), then AFAIK, fully remote-managing a Mac usually involves adding a network-capable power switch and an outboard network-capable KVM adapter. (The Xserve was the last box with (limited) remote-management capabilities, and there's not been any indication that Apple might be releasing systems with Intel AMT (iAMT, vPro) support available and enabled.)

Data back up from Single User Mode

Hello,
I have a problem with my 700 MHz iBook, dual USB, with OS X 10.3.9.
Unfortunately the OS doesn't start up because of "overlapped extent allocation" problem...
I would like to re-install the complete OS but before doing it, I would like to back up some directories.
Is it possible to save some data, by connecting an Ipod or some sort of external peripheral, from the Single User mode?
If yes, how can I do it?
Thank you in advance from your kind support.

Before giving up the ghost check out these:
http://docs.info.apple.com/article.html?artnum=25770.
Manually fix Overlapped Extent Allocation Errors without Disk Warrior
Overlapped overlapped extent allocation errors can be the bane of any Mac user's existence. Often, these errors go unnoticed until the problem becomes visible: your Mac might refuse to boot, crash unexpected, or worse, critical data might disappear from the Finder. Disk Utility can detect, but not fix overlapped extent allocation errors, and certain third-party utilities, such as Alsoft Diskwarrior, can fix them, but generally without reporting the consequences.
Overlapped extent allocation error occur when the file system thinks that two files are occupying the same area on the hard disk, hence overlapping on the same "inode," which is the structure which holds the location of the data blocks the file occupies, and also file permissions and flags.
Clearing the "overlapped" or "overallocated" extent allocation essentially means that you'll have to lose some data, because the only way to remove the overlap is to delete the file that's occupying the inode. So, if you suspect, or find out, that the guilty file is a critical system file that resides in one of the hidden system directories such as /etc /var /usr/ or visible system directories such as /System or /Library, and you don't want to reinstall the whole OS (which might not fix the overlapped extent allocation anyway), it's good to have another disk available to copy the files back to your original disk if necessary: a second bootable hard drive or a firewire drive connected to your Mac when you remove the misbehaving file. Just make sure that when you copy the file back to your boot disk that the permissions are correct, so it's best to use the "ditto" command, so that all sticky bits, flags, and permissions are preserved.
In case you didn't know, you don't have to boot from an install CD in order to check for overlapped extent allocations. All you need to do is restart your Mac, while holding down command + S to boot in "single-user mode."
At the command prompt that appears, type:
$ fsck -fy
If you have an overlapped extent allocation, you'll see:
"Overlapped Extent Allocation" (File 123456d)
No matter how many times you run fsck -fy, you'll never be rid of the error.
So, simply issue the following command:
find / -inum 123456 -print
Note the "d" was dropped, or any extra letter that appears after the inode number.
The find will return a file name that matches with the inode number, and the path to that file. If you remove the file then the fsck will not return this error next time you run it.
However, before you can delete the file(s) in single-user mode, you'll need to mount the file system. Type:
$ mount -uw /
When done, issue the "sync" command, and that will flush the write cache so that all pending writes are written from memory to the disk. Also, since most OS X 10.3 Macs use the HFS+ Journaled file system, it might be a good idea to disable the journal before booting into single-user mode by typing:
$ sudo diskutil disableJournal /
then re-enable it when done fixing the overlapped extents and rebooting normally:
$ sudo diskutil enableJournal /
Chris Anderson is a long-time Linux propellerhead who just got his first Mac, an ibook G4, and can't keep his hands off of it. He currently works as a "The Architect" and general visionary for a maker of world-class collectibles.
If you own Disk Warrior then it should be able to repair a drive with overlapped extents.
There are two backup utilities included in Unix - psync and rsync. You will find them in the /usr/bin/ directory. For documentation simply enter: man psync or man rsync. In order to write data while in single-user mode you need to issue the command: /sbin/mount/ -uw / (Note: there is a "space" between the "uw" and the "/".) To mount an external drive you will need to provide the mountpoint for it in place of the "/", e.g., "/Volumes/volname") without the quotes.

Why can't I enter single user mode on my Mac Mini for an admin password reset?

Hi,
I recently created a new user account for my mac and deleted the old one, not realising that this was the only account with admin priveleges. As such, I no longer have access to administrator priveleges, and cannot grant them to my new user account.
I have tried to boot in single user mode and recovery mode but neither command results in any reaction on the part of my computer.
This thread follows on from a previous, unrelated disscussion:
BDAqua: If you hold alt key at bootup do you see a lock in the middle?
Yenots: No...what does this mean?
BDAqua: If it did, it would mean Firmware Password Protection was enabled, which prevents booting in other modes, so that's not the problem, are you using a wired Mac KB, or Windows KB?
Yenots: I'm using an 'Apple Keyboard with Numeric Keypad' [ http://store.apple.com/uk/product/MB110B/B/apple-keyboard-with-numeric-keypad-br itish ]
If you find me here BDAqua, hit me with your knowledge!
Any other contributions are welcome and, now we're under the right heading, will hopefully help other users who have encountered this problem.
Thanks, Cristo

Hi,
Thanks for the link to MacPilot, and the sexy screenshot. I found an archived version for 10.4 on the koingosw website. That solves getting into single user/safe mode. Though I'd be interested to see whether sudo nvram boot-args="-s" will result in single user boot.
As for creating administrator priveleges for my new user account, I've found a method which looks good:
     \single user mode\
     cmd-s
     \mount drive\
     mount -uw
     \open 'directory access'\
     lauchctl load /System/Library/LaunchDaemons/com.apple.opendirectory.plist
     \list users\
     ls /Users
     \change password\
     dscl . passwd /Users/<username> <password>
I think that this method intends that if I change the root users password I'll be changing the administrator password (as root is the only user with administrator priveleges), and subsequently be able to change my new user accounts priveleges using 'netinfomanager'. But I'm not 100%. Could you give me your opinion on this?
Furthermore, three keys 'L' 'O' and '(' aren't working on my keyboard, which means I can't try this until I find an intact keyboard to borrow. I was thinking maybe a mod version of the above instructions would work in terminal using sudo, so I could use the keyboard viewer to type the missing characters. If you have any ideas on constructing such a mod I would be interested to hear them.
Otherwise, Thank You for your help BDAqua! And enjoy your summer wherever you are.

MBP starts up in Single User Mode by default..

I restarted the machine because the trackpad was acting up. After file vault reclaimed unused disk space, the computer restarted with a black screen with "localhost :/ root#" in the upper left screen. I know very little unix so please forgive my lack of lingo.
How can I possibly get back to the graphical multi user login? I have tried to restart in safe mode and from the install dvd but they just bring me back to the "localhost :/ root#" black screen. I have also restarted holding down the option key to select a drive, which I set to my drive name, and same thing-- Apple logo on a grey screen, spinning gear, then black screen localhost :/ root#. Only thing I havent tried that im aware of is target mode, but my other computer (Rev A. iMac) which is the machine I am writng this from is on OS 9 with no fire wire and just a 4g drive.
So I need some advice if you have any. Hardware appears fine save for the trackpad and button being touchy. Apple has already replaced my swelling battery. They told me the new mbp's have a barrier between the the battery and trackpad assembly, (a prior neglected, inherent design flaw).
I do have a new USB external hd. Is there any way to login my home folder and completely copy the home folder contents to it in single user mode? If I could do this, I would at least be able to keep my itunes librarys, playlists, keychain data, mail, etc.. Thanks in advance for any help any of you may have

Ok, I did the dmesg command at the prompt. Here is word for word what it spit out:
localhost:/ root# dmesg
hi mem tramps at 0xffe00000
PRE enabled
standard timeslicing quantum 10000 us
vmpagebootstrap:513016 free pages
migtable_maxdispl = 71
Enabling XMM register save/restore and SSE/SSE2 opcodes
96 prelinked modules
ACPI CA 20060421
AppleIntelCPUPowerManagement: ready
AppleACPICPU: ProcessorApicId=0 LocalApicId=0 Enabled
AppleACPICPU: ProcessorApicId=1 LocalApicId=1 Enabled
Copyright (c) 1982, 1986, 1989, 1991, 1993
The Regents of The University of California. All Rights Reserved.
using 10485 buffer headers and 4096 cluster IO buffer headers
Enabling XMM register save/restore and SSE/SSE2 opcodes
Started CPU 01
IOAPIC: Version 0x20 Vectors 64:87
ACPI: System State [S0 S3 S4 S5] (S3)
Security auditing service present
BSM Auditing Present
disabled
rooting via boot-uuid from /chosen: 00001B5D-7D26-0000-2F5D-000090200000
Waiting on <dict ID="0"><key>IOProviderClass</key><string ID="1">IOResources</string><key>IOResourceMatch</key><string ID="2">boot-uuid-media</string></dict>
USB caused wake event (EHCI)
FireWire (OHCI) Lucent ID 5811 PCI now active, GUID 0016cbfffe523440; max speed s400.
Got boot device =IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/SATA@1F,2/AppleAHCI/PRT 2@2/IOAHCIDevice@0/AppleAHCIDiskDriver/IOAHCIBlockStorageDevice/IOBlockStorageDr iver/ST9100824AS Media/IOGUIDPartitionScheme/Customer02
BSD root: disk0s2, major 14, minor 2
CSRHIDTransitionDriver::probe:
CSRHIDTransitionDriver::start before command
CSRHIDTransitionDriver::stop
IOBluetoothHCIController::start Idle Timer Stopped
disk0s2: 0xe0030005 (UNDEFINED).
localhost:/ root#
A couple of things to note:
1. I did have an external bootable drive, which does work properly when selected as the Startup Disk, but still registers when not plugged in the machine.
2 File Vault is turned on. And let me tell you. If you ever use more than half your drive space, as most people do, you will have a humbling experience. File Vault is overkill. I am angry that Apple could not come up with a "fail-safe" for legitimate, password bearing rightful owners.
I just want one chance to get in my home folder to get what I want (my music, photos, mail, passwords, widgets, etc.)

How to mount USB & CDROM drives from single user mode - Solaris boot disk?

Hi All,
I need to carry out ufsrestore on a single newly replaced system disk (no redundancy / mirroring) from either USB or CDROM drives from the following steps:
( i ) GRUB => e, e, cdrom –s, Enter, b (boot from Solaris 10 x86 media).
( ii ) Choose menu 1 for Install Solaris Interactive Mode to reach single user mode.Below are the commands that I have tried in single user mode without success:
mount –r –F pcfs /dev/dsk/c1t0d0p0 /cdrom (after unmount Solaris CD)
mount: /dev/dsk/c1t0d0p0 is not a DOS filesystem.
svcadm –v enable smserver
svcadm: Pattern ‘smserver’ doesn’t match any instances
svcadm enable autofs
svcadm: Pattern ‘autofs’ doesn’t match any instances
devfsadm
devfsadm: mkdir failed for /dev 0s1ed: Read-only file system
mkdir /mnt
mkdir: Failed to make directory “/mnt”; Read-only file systemPart of the problem is due to the current READ ONLY filesystems which does not allow the creation of mount point such as /mnt.
I have been able to create both / root (/dev/dsk/c1t0d0s0) and /export/home (/dev/dsk/c1t0d0s0) filesystems with newfs that are awaiting for restore using ufsrestore.
The only option I am left with is to attach a secondary disk to install Solaris 10 on either of them before bring the system to multi-user mode so that service such as volmgt, autofs, volfs are available to access USB & CDROM drives.
Any suggestion on how to resolve this issue?
Many thanks,
Jack

Hi JKGN,
Is the directory a located under the root filesystem. ie /a? Are there any other mount point for say USB drive as well? I am not in a position to try it out right now but will get back
to you soon on whether /a exist or not.
Btw, the last thing I managed to do on this system at the time was added a secondary 1TB internal disk with the intention to restore both / and /export/home data onto this disk while
making use of all the disk device management services such as the following services only available in a fully installed Solaris system (both single & multi-user modes) installed on the
primary disk:
# svcs smserver
STATE          STIME    FMRI
online         Jun_08   svc:/network/rpc/smserver:default
# svcs autofs
STATE          STIME    FMRI
online         Jun_08   svc:/system/filesystem/autofs:default
# devfsadm
# iostat -En
c1t0d0           Soft Errors: 0 Hard Errors: 0 Transport Errors: 0
Vendor: ATA      Product: SAMSUNG HD321KJ Revision: 0-11 Serial No:
Size: 320.07GB <320072932864 bytes>
Media Error: 0 Device Not Ready: 0 No Device: 0 Recoverable: 0
Illegal Request: 41 Predictive Failure Analysis: 0
c0t0d0           Soft Errors: 0 Hard Errors: 5 Transport Errors: 0
Vendor: PHILIPS Product: DVD+-RW DVD8801 Revision: AD21 Serial
Size: 17.54GB <17538875392 bytes>
Media Error: 0 Device Not Ready: 5 No Device: 0 Recoverable: 0
Illegal Request: 10 Predictive Failure Analysis: 0
c2t0d0           Soft Errors: 0 Hard Errors: 0 Transport Errors: 0
Vendor: JetFlash Product: Transcend 16GB   Revision: 1100 Serial No:
Size: 0.00GB <0 bytes>
Media Error: 0 Device Not Ready: 0 No Device: 0 Recoverable: 0
Illegal Request: 7 Predictive Failure Analysis: 0
# rmformat
Looking for devices...
     1. Volmgt Node: /vol/dev/aliases/cdrom0
        Logical Node: /dev/rdsk/c0t0d0s2
        Physical Node: /pci@0,0/pci-ide@1f,1/ide@0/sd@0,0
        Connected Device: PHILIPS DVD+-RW DVD8801 AD21
        Device Type: DVD Reader/WriterHowever, I was disappointed that "iostat -En" has not found the secondary disk (1 TB) even though it was available earlier, for Solaris installation as the only disk on the same system.
As a result, I am left with no option but the need to rebuild this system with only a single primary disk while in single user mode. However, the single user mode that I am in is the
one from Solaris installation disk with restrictive (_cannot create folder for mount point or running disk management utilities_) capability such as those services just covered, compared to one from a completed Solaris installation system with full access to all filesystems and utilities / commands in general.
I would very much value your assistance on how to mount both CD & USB in this restrictive limited Read Only OS (assume that it is running from memory) in order to get complete access to
the blank primary disk so that full restore with ufsrestore could take place.
Thanks in advance,
Jack
Edited by: 797805 on 9/06/2012 04:15

Resetting the Admin password in single user mode

Ok, my friend bought an old Imac from someone she went to school with with OS 10.4.2 on it. It works fine except that she can not install any programs because there is an admin password that she does not know. She asked the person she bought it from, he says he doesn't even remember setting a password. Normaly with this issue id just pop in the install disk and reset it from there, except neither of them have the install disk, and my install disk is to current for the machine. Does anyone know how I can reset the admin acount using single user mode commands? I can do it on my Mac Book pro but it doesn't seem to work the same way on 10.4. Please help!
EDIT: It is a Power PC G3 if that helps.
Message was edited by: CartooNxHerO

CartooNxHerO wrote:
Ok, so I used the advice from the third link you gave me but i'm still in single user mode trying to figure out how to delete the users home folders.
Message was edited by: CartooNxHerO
You do not need to delete "the users home folders". Nor do you need to delete the netinfo database. Here are two proceedures:
Change Password
Mac OS X:
Changing or resetting an account password via GUI:
Resetting a user's password
Resetting the original administrator account password
http://docs.info.apple.com/article.html?artnum=106156
You do not have a CD/DVD
Changing password from single user mode:
You can also change the administrator's password from single user mode or create a new administrator account.
You need to get into single use mode for steps one and two that are listed below.
This page will tell you how to get into single user mode.
http://support.apple.com/kb/HT1492
Basically, you hold down the command-s key then powering on your machine. The command key has a little apple symbol on the lower left. It is between the alt/option key and the space bar. On a PC keyboard, it will be the windows key, I think.
1) You can change the password on an account. ( Do you know Unix. You are in a Unix single user console. ) The setup commands you need should be listed on the screen. For Mac OS 10.4.11, the commands are:
# Type the follow two instructions to access the startup disk in read/write:
/sbin/fsck -fy
/sbin/mount -uw /
# Start up some utility processes that are needed.
sh /etc/rc
# You will probably need to press the return key once the system stops typing.
# To find out the users on the system type, use the list command. The l is a lower case L:
ls /Users
# One of these accounts will be the administrator.
# Pick one of the users which I'll call a-user-name and type it in this command:
passwd a-user-name
# and enter the new user password. You need six characters.
# You will need to enter your password twice. Your typing will not show up on the screen just
# press enter when you complete the typing.
# For cryptic information on these commands try:
man ls
man passwd
The root account isn't enabled by default. I am not sure if changing the password on root will enable it.
2) Get the Mac to set up an additional administrative account. You can then change the password on your old account.
Start with your computer power off. Hold down command-s. Power on your computer.
Type in the following:
The first two commands will depend on your release of Mac OS X. Look at what is typed out in the console to determine the exact format.
# Type the follow two instructions to access the startup disk in read/write. Press return after each command.
/sbin/fsck -fy
/sbin/mount -uw /
cd /var/db
pwd
#List all files. The l is a lower case L.
ls -a
#The move command acts as a rename command in this format.
mv -i .applesetupdone .applesetupdone.old
reboot
Once you've done that the computer reboots and it's like the first time you used the machine. Your old accounts are all safe. From there you just change all other account passwords in the account preferences!!
Limnos adds detailed explainations:
http://discussions.apple.com/message.jspa?messageID=8441597#8441597
The above the idea came from a post by JoseAranda at September 9, 2006 3:48 AM
http://www.askdavetaylor.com/howdo_i_reset_my_mac_os_x_admin_rootpassword.html
You will need to scroll down to see this post. Search for applesetupdone
Or see:
http://superpixel.ch/articles/running-setup-assistant-again/
Once you have a new administrative account, you can change the password of your old administrative account
blue apple > System Preferences > Accounts

Difference between emergency state and single user mode ?

Hi,
I want to know the difference between emergency state which we normally use in suspect mode database and single user mode.
Navakanth

Emergency/suspect mode is tells you the state of the database and database is not available for user action but where as single user mode tells the user action preference. Database is active and available for the user action.
You can refer
http://msdn.microsoft.com/en-us/library/bb522682.aspx
EMERGENCY
The database is marked READ_ONLY, logging is disabled, and access is limited to members of the sysadmin fixed server role. EMERGENCY is primarily used for troubleshooting purposes. For example, a database marked as suspect due to a corrupted log file can be
set to the EMERGENCY state. This could enable the system administrator read-only access to the database. Only members of the sysadmin fixed server role can set a database to the EMERGENCY state.
SINGLE_USER
Specifies that only one user at a time can access the database. If SINGLE_USER is specified and there are other users connected to the database the ALTER DATABASE statement will be blocked until all users disconnect from the specified database. To override
this behavior, see the WITH <termination> clause.
The database remains in SINGLE_USER mode even if the user that set the option logs off. At that point, a different user, but only one, can connect to the database.
Before you set the database to SINGLE_USER, verify the AUTO_UPDATE_STATISTICS_ASYNC option is set to OFF. When set to ON, the background thread used to update statistics takes a connection against the database, and you will be unable to access the database
in single-user mode. To view the status of this option, query the is_auto_update_stats_async_on column in the sys.databases catalog view.
If the option is set to ON, perform the following tasks:
Set AUTO_UPDATE_STATISTICS_ASYNC to OFF.
Check for active asynchronous statistics jobs by querying the sys.dm_exec_background_job_queue dynamic management view.
If there are active jobs, either allow the jobs to complete or manually terminate them by using KILL STATS JOB.
--Prashanth

Start SQL Server in single user mode with parameter -m doesn't work well

C:\Windows\system32>net start mssqlserver /m "Microsoft SQL Server Management St
udio - Query"
The SQL Server (MSSQLSERVER) service is starting.
The SQL Server (MSSQLSERVER) service was started successfully.
C:\Windows\system32>sqlcmd -S . -e
1> go
1> select @@servername;
2> go
select @@servername;
myserver
(1 rows affected)
1>
As you can see, I'm still able to connect with sqlcmd prompt to SQL Server. According production doc of SQL Server 2014, it should not be conncting by sqlcmd. it shall only be connected by SSMS.
below the original doc on msdn:
Start SQL Server in Single-User Mode
Provide Feedback
Under certain circumstances, you may have to start an instance of SQL Server
in single-user mode by using the startup option -m. For
example, you may want to change server configuration options or recover a
damaged master database or other system database. Both actions require starting
an instance of SQL Server in single-user mode.
Starting SQL Server in single-user mode enables any member of the computer's
local Administrators group to connect to the instance of SQL Server as a member
of the sysadmin fixed server role. For more information, see Connect to
SQL Server When System Administrators Are Locked
Out.
When you start an instance of SQL Server in single-user mode, note the
following:
Only one user can connect to the server.
The CHECKPOINT process is not executed. By default, it is executed
automatically at startup.
Note
Stop the SQL Server Agent service before connecting to an instance of SQL
Server in single-user mode; otherwise, the SQL Server Agent service uses the
connection, thereby blocking it.
When you start an instance of SQL Server in single-user mode, SQL Server
Management Studio can connect to SQL Server. Object Explorer in Management
Studio might fail because it requires more than one connection for some
operations. To manage SQL Server in single-user mode, execute Transact-SQL
statements by connecting only through the Query Editor in Management Studio, or
use the
sqlcmd utility.
When you use the -m option with sqlcmd or
Management Studio, you can limit the connections to a specified client
application. For example, -m"sqlcmd" limits connections to a
single connection and that connection must identify itself as the
sqlcmd client program. Use this option when you are starting
SQL Server in single-user mode and an unknown client application is taking the
only available connection. To connect through the Query Editor in Management
Studio, use -m"Microsoft SQL Server Management Studio - Query".
Shawn

Hi Shawn Xiao,
For starting SQL Server instance in single user mode, we can add –m; parameter in SQL Server Configuration Manager, also we can run CMD with ‘Run as administrator’ and input the following statement.
NET START MSSQLSERVER /m
I do a test in SQL Server 2014 Express version, after starting SQL with Single User Mode, SQL Server will only accept one connection. If you connect to SQL Server with a user account, the following error will occur.
Login failed for user ‘domain\username’. Reason: Server is in single user mode. Only one administrator can connect at this time.
However, in your situation, you can connect to SQL Server and run T-SQL statement successfully, it can be due to connection with the administrator account in your sqlcmd.
For more information, you can review the following article.
http://zarez.net/?p=117
Regards,
Sofiya Li
Sofiya Li
TechNet Community Support

Terminology question: "booting as root" vs. "booting in single user mode"

Terminology question: "booting as root" vs. "booting in single user mode". Are these terms interchangeable, or is there a subtle or not-so-subtle difference? (Obviously something I don't do often.)
Thanks in advance.

Boot to Single user allows root access.
It isn't "booting to root" as in Linux, but I think is as close as it gets.
You can enable root from a normal boot:
http://www.youtube.com/watch?v=Y-JEpDi-cME
Interesting read:
http://www.securemac.com/macosxsingleuser.php
This is fun:
http://osxdaily.com/2007/01/22/what-happens-in-the-mac-os-x-boot-process/

How do I prevent users from logging into my machine in single user mode?

I established an standard accounts for my family. My son figured out that if he logs into the machine in Single User mode that he logs in as the root user. He then proceeded to create another user with administrative privileges and change his account to administrator then delete the other account. Funny thing about this is that as much as OS X is secure from outside threats a simple command-s gets you right into the very heart of the machine......

You can set a firmware password. The firmware password only allows you to start up in normal mode, so if you try to start in single-mode user or safe mode, your Mac will ask you for a password.
The process to turn it on depends on the OS X version you have. Open  > About this Mac, check the Mac OS X version and follow the steps depending on your OS X version.
If you have 10.7 or 10.8:
1. Hold Command and R keys while your Mac is starting up.
2. After starting up into OS X Utilities, go to Utilities menu (on the menu bar) > Firmware Password Utility, and enable the firmware password.
3. Restart the Mac.
If you have 10.6 or older:
1. Insert the Mac OS X disc and hold the C key while your Mac is starting up.
2. Choose your language, go to Utilities menu (on the menu bar) > Firmware Password Utility, and enable the firmware password.
3. Restart the Mac.
Also, this will protect your Mac against thieves because they won't be able to erase the hard drive without knowing the firmware password. Don't forget the password, because only Apple can reset it if you don't know this password

Disable single user mode

Is there a way to disable single user mode? I just booted in single user mode and w/o any password I changed my root password! In my mind this is a HUGE security hole, any one could gain root access to my laptop in a matter of less than a minute! I might as well not have a root password. I have the latest and greatest security updates, but this seems to be the biggest security risk in my mind.

If someone has physical access to your computer, your software is vulnerable in the way that you describe. There are a couple of approaches to preventing this problem. I have not tried any of this so I can only point you to some websites.
One way to prevent anyone booting into single user mode is to enable a password in Open Firmware, as described at Setting up firmware password protection in Mac OS X 10.1 or later. You would have to enter the password every time that you booted. And, you definitely would not want to forget your password; if you did, I don't know what you would have to do to recover.
A second approach is to use a 3rd party patch to prohibit casual use of the single-user feature. Look here for info on such a patch: Mac OS X Single User Mode Root Access. I believe that the software discussed here forces someone to type in a password to boot in single-user mode.
One question that I have about the second approach is whether it is possible for the patch to become out of synch with a future OS update. If that happened, one would also need a way to recover.
I hope this helps. If you are really concerned, I suggest that you do some internet searching on this topic.
Rich
EMAC G4 1.0 GHz Mac OS X (10.4.8)

How do i repair my hard drive in single user mode when disk is full?

Hi there Apple Community!
I have an old Macbook Pro 17" with an upgraded 500GB harddrive and 4GB memory. I'm running Mac OSX Lion.
Was hoping you could help me out. THis is the situation:
Long story short I spilt wine on my macbook and the screen went a bit blobby. Switched it off for a few days, removed the battery etc. etc. Opened it up cleaned out as much of the wine as possible, but unfortunately some of it came in behind the LCD, so now the screen has a nice red stain. Obviously I'm not going to try to clean that out of the LCD.
My Macbook Pro still worked for a few days after that, but then my harddrive gave up. I booted in the Recovery HD menu, verified the drive and I got the error "Keys out of order - This disk needs to be repaired, click Repair Disk." I attempted to repair the disk but got the error "Keys out of order - Disk Full Error - The volume could not be repaired".
Unfortnately of this 500GB I only have about 7GB free on it, as I have a huge iPhoto and iTunes library. I did make a TIme Machine backup of my user directory, but not the system files. I don't really want to do a clean install because:
1) I'm paranoid that there's something I did not fully back up
2) I don't want to have to download the whole Mac OSX Lion again. I should have made a USB bootable backup when I had the chance. I don't have access to a broadband connection.
What I feel are my viable options, are as follows:
1) I did buy a replacement internal 500GB harddrive, so I can probably try to make an image of the hard drive to this new drive, but not sure how. I believe it's through the Disk Utility with the "New Image" option but not sure how to go from there.
2) Start up in Single User Mode and delete some unnecessary files and re-attempt to run the fschk -fy utility again (I tried this earlier and got the same Disk Full Error). - the problem with this is, I'm not familiar with the command line and have no clue how to delete files. I don't know my way around Unix.
3) I can also probably attempt to make a Ghost Image or Acronis Image of the failed drive to this new drive, but not sure if Norton Ghost or Acronis True Image will be able to read this HFS drive - I believe it's possible as it's a simple hard drive clone.
If you can guide me in the best option - probably there is a better solution than my proposed ones above, I appreciate any feedback and comments you might have!

hi Baltwo,
So I ended up copying my user folder to another harddrive. I managed to download the whole osx lion again, reinstalled, and recovered my home folder using this discussion:
http://support.apple.com/kb/HT1428
I have managed to get all my files back. My iTunes library works fine, but my iPhoto library when I open it, get the following error:
iPhoto cannot be opened because of a problem.
Here's the error log
Process:         iPhoto [1540]
Path:            /Applications/iPhoto.app/Contents/MacOS/iPhoto
Identifier:      com.apple.iPhoto
Version:         8.1.2 (8.1.2)
Build Info:      iPhotoProject-4240000~8
Code Type:       X86 (Native)
Parent Process: launchd [209]
Date/Time:       2012-09-19 19:56:45.528 +0200
OS Version:      Mac OS X 10.7.4 (11E53)
Report Version: 9
Sleep/Wake UUID: 7948ABE2-5294-4F87-B6E3-777095A2F2EE
Interval Since Last Report:          4780 sec
Crashes Since Last Report:           9
Per-App Crashes Since Last Report:   9
Anonymous UUID:                      70117D38-03EA-4F9C-B810-50B743864B9E
Crashed Thread: 0
Exception Type: EXC_BREAKPOINT (SIGTRAP)
Exception Codes: 0x0000000000000002, 0x0000000000000000
Application Specific Information:
dyld: launch, loading dependent libraries
Dyld Error Message:
Library not loaded: /System/Library/PrivateFrameworks/iLifeSlideshow.framework/Versions/A/iLifeSlid eshow
Referenced from: /Applications/iPhoto.app/Contents/MacOS/iPhoto
Reason: image not found
I've done an Apple Software Update but it didn't find an update for iPhoto.
One thing to note is, this library was originally created on iLife 08, upgraded to '09 and it stayed on that version. It hasn't een upgraded to iLife '11. It worked fine on my previous install of OSX Lion. How do I recover the library without upgrading to '11 ?

Kernel panic on MacPro in Single-User mode after memtest.

I've had about 7 kernel panics in about 7 days on a new MacPro. 2 gigs of RAM (Apple Installed). Fresh install of OSX (no user import). While going through the troubleshooting process I ran memtest in single user mode. Ran it all night no errors.
So in the morning I typed ctrl-c and then exit (i think)... it seemed to start the process of booting and I got another kernal panic. I've actually done this three times now.
I checked panic.log and all the error messages but 1 were the same. Including the ones I got in single-user mode (copied below).
Should I be able to gracefully exit out of single-user mode without a kernel panic?
Does this point to a RAM error even though memtest and AHD for that matter ran all night without finding anything?
I'm all set to try again (taking careful notes this time) to see if I can reproduce but I was hoping for some feedback first.
Thanks,
Craig
Sat Jan 27 22:17:27 2007
panic(cpu 0 caller 0x41C47CC4): Uncorrectable Fbd memory error detected. ferr = 20000000 , nerr == 00000000, fErrFat = 20000000 nErrFat == 00000000
Backtrace, Format - Frame : Return Address (4 potential args on stack)
0x108cd8 : 0x128d08 (0x3c9a74 0x108cfc 0x131de5 0x0)
0x108d18 : 0x41c47cc4 (0x41c49f1c 0x20000000 0x0 0x20000000)
0x108da8 : 0x41c47f58 (0x406a180 0x406a180 0x2 0x820044)
0x108e38 : 0x66a712 (0x406a180 0x0 0x3ba3680 0x0)
0x108e68 : 0x66a59b (0x3b92780 0x0 0x0 0x1c)
0x108e88 : 0x67d9be (0x1c 0x108ef8 0x8 0x67f4be)
0x108eb8 : 0x67db68 (0x3b91b1c 0x17 0x3b928ca 0x3b81120)
0x108f18 : 0x68a743 (0x3b34348 0x0 0xafdd0c77 0x4cd5)
0x108f38 : 0x70a4fb (0x3b34348 0x0 0x3abac80 0x0)
0x108f68 : 0x67053f (0x3b88600 0x0 0x3b87580 0x49)
0x108f88 : 0x669c1f (0x3b6b800 0x0 0x3b87580 0x49)
0x108fa8 : 0x3ba298 (0x3b87100 0x0 0x3b92f00 0x49)
0x108fe8 : 0x19aa80 (0x25423e30 0x25423e30 0x19bad6 0xb26000)
0x25423f18 : 0x1a445b (0x10 0x1 0x4af85c 0x6)
0x25423f38 : 0x19d871 (0x0 0x0 0x25423f68 0x206)
0x25423f58 : 0x135f14 (0x0 0x0 0x0 0x19d23a) Backtrace continues...
Kernel loadable modules in backtrace (with dependencies):
com.apple.driver.AppleMCEDriver(1.1.2f1)@0x41c44000
dependency: com.apple.iokit.IOACPIFamily(1.2.0)@0x664000
com.apple.driver.AppleAPIC(1.2.0)@0x709000
com.apple.driver.AppleACPIPlatform(1.0.8)@0x668000
dependency: com.apple.iokit.IOPCIFamily(2.2)@0x57d000
dependency: com.apple.iokit.IOACPIFamily(1.2.0)@0x664000
Kernel version:
Darwin Kernel Version 8.8.4: Sun Oct 29 15:26:54 PST 2006; root:xnu-792.16.4.obj~1/RELEASE_I386
MacPro Mac OS X (10.4.8)

Welcome to Apple Discussions!
Yes, your memory or memory slot, or memory seating is bad or off. "Uncorrectable Fbd memory error detected. ferr = 20000000 , nerr == 00000000, fErrFat = 20000000 nErrFat == 00000000"
Clearly a memory related issue. It may also be that memtest doesn't know how to diagnose the new kind of memory and is reporting that back to the logs. Take it in to a service center to have all the boards replaced to make sure the issue isn't reproduceable with new memory. If it is, then I'd consider the slots on the logicboard a problem.

Re-Enabling Single User Mode :\

Similar Messages

Maybe you are looking for