Hi Ronni & Adam,

I have been following this with interest ­ I have had to sort out
permissions problems in the past, I generally get there in the end, but I
still find many aspects of permissions confusing.


I am hoping that Ronni could clarify how one area works:


I can see how approach A works ­ this is basically just like taking home a
new computer and migrating the data over from the old computer.

With approach B, however how does the UID get back in sync ­ or does OSX
work around that?

To elaborate on my query:

* It sounds like the old computer was set up with just the primary user
account, which would have had the default UID of 501 for the main account ­
this is the account now on the back-up disk that we want to restore.
* The technician set-up one main account on the new HD ­ which is therefore
also UID 501 ­ but with other details wrong (as per Adam¹s id printout:
>> admins-imac:~ adam3$ id
>> uid=501(adam3) ..............
* If Adam creates a NEW Administrator Account with exact details of the User
Account that he has on the backup drive it will presumably get a UID of 502
(501 is already taken) - so the exact details may be the same but the UID
will be different. 
* When Adam DELETES the OLD Account ­ he is deleting the account currently
with UID 501.


So this is where I am unclear as to how things proceed:

* Would deleting account UID 501 result in the new account getting its UID
re-assigned from 502 to 501? or
* Would migrating over the OLD account UID 501 result in the new account
getting its UID re-assigned from 502 to 501? or
* Would the new account retain the UID 502 but the migrated files get their
ownership modified to suit this? or
* I¹m missing the point, what happens is ........

If the (new) main account has UID 502, would there be any problems at the
next migration to a new computer (with main account UID 501)?


Ronni, I hope you don¹t mind me jumping in with these questions ­ but I know
that many of us find permissions intricacies somewhat confusing.


I know I had big problems in the past when I set up a new computer with an
account that was ALMOST the same as the old one! (I can¹t remember now
whether the short names were the same but the user names different, or
vice-versa, or names the same but UIDs different) - I remember it was a
painful process sorting it out.


Cheers



Neil

-- 
Neil R. Houghton
Albany, Western Australia
Tel: +61 8 9841 6063
Email: n...@possumology.com



on 19/5/10 9:30 AM, Ronda Brown at ro...@mac.com wrote:

> Hi Adam,
> 
> On 18/05/2010, at 8:35 PM, Adam Lippiatt wrote:
> 
>> Ronni
>> 
>> Thanks for this.  I did have a backup of the drive but unfortunately after
>> having the machine for more than a month I think the technician got
>> exasperated and just wanted to see the back of it.  So, I got a new hard
>> drive which was, unfortuantely, a little noisier than the original and also
>> the install was done on a new user account which did not have the same name
>> as the old one.
>> 
>> So, perhaps this is the source of the permissions problems.
> 
> Definitely, for sure Š You don't 'own' (have Permissions) of the files,
> another User does! As I explained in my previous email.
> 
> A couple of things need clarifying Adam.
> 1. You say you DID have a backup of the old Hard Drive (User Accounts /
> Settings / Data) Š do you still have that backup?
> 
> 2. Did the Technician do the New Install and create a New (different) User on
> the new Hard Drive?
> If so, he would have / or should have told you that you needed to create a new
> Administrator Account with EXACTLY the 'same User Name & Short Name  &
> Password' that your Original Drive (& backup) have.
> Then 'Log Out' of the 'Wrong  Account' , 'Log In' to the New Account (you have
> created exactly as is on the backup drive) & under System Preferences DELETE
> the 'Wrong User Account'.
> ThenTransfer everything across from the firewire 'Backup' Drive.
> 
> What to recommend you do now to sort the mess out???
> A or B?
> 
> A.  Do a complete Erase of your Hard Drive and Clean Install of Snow Leopard.
>      1. Startup from the SL install disk, erase the hard drive with disk
> utility (on the Disc) .
>       2. Quit disk utility,  and proceed with the install.
>       3. On the first reboot it will offer to migrate your data from a Time
> machine backup or an External Drive. Choose your External Drive and  migrate
> from the backup you have.
>      (i.e When your computer restarts with the clean install, DON'T create a
> User Account, let Migration Assistant transfer your User Account / Settings /
> Files from the External Backup Drive Š )
> 
> 
>  B.  Do 2 that I mentioned above:
>       1. Create a NEW Administrator Account with exact details of the User
> Account that you have on the backup drive
>       2. 'Log out' of the OLD Administrator (wrong) Account.
>       3. 'Log In' to the NEW Administrator Account
>       4. DELETE the OLD Account
>       5. Transfer your Data across from the Backup Drive.
> 
> Cheers,
> Ronni
> 
> 
>> I did the id command and got the following:
>> 
>> admins-imac:~ adam3$ id
>> uid=501(adam3) gid=20(staff)
>> groups=20(staff),101(com.apple.sharepoint.group.1),204(_developer),100(_lpope
>> rator),98(_lpadmin),81(_appserveradm),80(admin),79(_appserverusr),61(localacc
>> ounts),12(everyone),401(com.apple.access_screensharing)
>> admins-imac:~ adam3$
>> 
>> Thanks for your help.
>> 
>> Adam 
>> 
>> Begin forwarded message:
>> 
>>> Hi Adam,
>>> 
>>> On 17/05/2010, at 12:03 PM, Adam Lippiatt wrote:
>>> 
>>>> Thanks Ronda
>>>> 
>>>> I will look into that. Unfortunately when the hard drive died I had to do a
>>>> lot of manual shifting of things as the service people could only give me a
>>>> fresh install with the data sitting in folders on the desktop. As time goes
>>>> by I am getting through all of the little issues.
>>> 
>>> Hmmm, this doesn't sound good to me. From reading above, I take it you did
>>> not have a 'Backup' of the Drive before it was corrupted?
>>> If the service people have just given you what they recovered from the
>>> corrupted drive Š and you are trying to copy these files onto the fresh
>>> install, there could be corruption in some of the files.
>>> 
>>> Did you create an 'exact' User Account on the Fresh Install as the 'User'
>>> you had on the original hard drive?
>>> If you didn't, you will run into Permission problems, as you will find the
>>> UID & GID are not the same.
>>> 
>>> Mac OS X displays the user name of the account that owns a folder or file,
>>> it¹s easy to assume that that account with that user name owns the item. In
>>> reality, it¹s not quite so simple.
>>> The owner is actually determined by a number called the UID‹the user
>>> identification number, not by the user name.
>>> In addition the group is, in fact, determined by the GID‹the group
>>> identification number.
>>> 
>>> To reveal your account¹s UID and primary GID, type id in a Terminal window
>>> (and then press Return).
>>> The output of the id command looks like this:
>>> ronni$ id
>>> uid=501(ronni) gid=20(staff)
>>> groups=20(staff),204(_developer),100(_lpoperator),98(_lpadmin),81(_appserver
>>> adm),80(admin),79(_appserverusr),61(localaccounts),12(everyone),401(com.appl
>>> e.access_screensharing)
>> 
>> 
> 
> 



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