/boot/grub/device.map keeps things mapped by logical location and uuid. if
you created a new partition, even if it had the same UUID, it would have a
different logical address.
On Tue, Dec 30, 2014 at 7:41 PM, Michael Havens <
bmike1@gmail.com> wrote:
> better yet could someone come explain it to us:
>
> http://www.bleepingcomputer.com/forums/t/561405/new-partition-scheme/page-2#entry3582631
>
> :-)~MIKE~(-:
>
> On Tue, Dec 30, 2014 at 7:38 PM, Michael Havens <bmike1@gmail.com> wrote:
>
>> I'm part of another discussion in which we are talking about UUIDs.
>> This is what one of the participants said:
>>
>> As pointed out earlier by bmike1 in response to my comment about GRUB2
>> not being able to find the OS if you move the partitions, by default on
>> Linux Mint GRUB2 will use UUIDs *(the id tag for your partitions)* instead
>> of partition numbers*(eg: sda1, sda2, etc)*, so I was incorrect when I
>> said GRUB2 won't be able to find the boot partition. Linux Mint's fstab *(a
>> config file read at boot to tell Mint which partitions should be
>> automatically mounted)* also uses UUIDs by default so no issues there.
>> Therefore I do not see any reason why moving your installation would be an
>> issue *(keep reading)*, so I decided to test it in a virtual machine. I
>> installed Linux Mint 17.1 - Cinnamon 64bit *(I've been wanting to try
>> Linux Mint for a while. I've been downloading a little bit of the ISO each
>> day)* with a partition layout similar to yours *(http://i.imgur.com/3qg0bSv.png
>> <http://i.imgur.com/3qg0bSv.png> )*. I wasn't able to move the extended
>> partition using Gparted, or create a new one. In the end I just created 3
>> new primary partitions and cloned the Linux Mint logical partitions to them
>> using dd *(dd is a sector based cloning tool that comes pre-installed on
>> most Linux operating systems. I used it because this way the new partitions
>> will have the same UUIDS as the Linux Mint ones did. This is important
>> since GRUB2 is using UUIDS to identify the boot partition and because the
>> fstab uses UUIDs to identify your swap partition)*. Then I deleted the
>> old partitions *( http://i.imgur.com/hDBT5ns.png
>> <http://i.imgur.com/hDBT5ns.png> )*. The result was that GRUB2 was
>> unable boot Linux Mint because it couldn't find the boot partition *(I
>> don't know why this is, but if I had to take a guess it would be that GRUB2
>> was probably storing part of itself on the extended partition's VBR which
>> no longer exists because I deleted the extended partition)*. So GRUB2
>> needed to be repaired. Using a Linux Mint Live-cd, I ran "sudo
>> add-apt-repository ppa:yannubuntu/boot-repair"*(this adds a third party
>> repo that has boot-repair in it, because it's not available in the default
>> Linux Mint repos)*, "sudo apt-get update" *(to update apts package list)*,
>> "sudo apt-get install boot-repair" *(to download and install
>> boot-repair)*, and then I ran boot-repair with its default settings *(be
>> warned by default boot-repair uploads information about your computer
>> online, you can disable this)*. This successfully fixed GRUB2, and I was
>> able to boot Linux Mint again *(http://i.imgur.com/ZJhXRbe.png
>> <http://i.imgur.com/ZJhXRbe.png> )*.
>>
>> I then said:
>>
>> I think I know why it needed repairing. The reason is that you created
>> new partitions (new UUIDs) and deleted the old partitions (the existing
>> UUIDs).
>>
>> to which he responded:
>>
>> The partitions were cloned with dd so that they would have the same
>> UUIDs. I also used "sudo blkid" to verify the uuids of the new primary
>> partitions matched before deleting the original logical partitions.
>>
>> He and I both remarked between the first and last quote that we thought
>> the UUID of the partition would of had it recognized regardless of what we
>> did with other partitions on the drive. Could someone kindly explain to us
>> wherein the difficulties lie?
>> :-)~MIKE~(-:
>>
>
>
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James McPhee
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~MIKE~(-:%0A>%20>%0A>%20>%20On%20Tue,%20Dec%2030,%202014%20at%207:38%20PM,%20Michael%20Havens%20<bmike1@gmail.com>%20wrote:%0A>%20>%0A>%20>>%20I'm%20part%20of%20another%20discussion%20in%20which%20we%20are%20talking%20about%20UUIDs.%0A>%20>>%20This%20is%20what%20one%20of%20the%20participants%20said:%0A>%20>>%0A>%20>>%20As%20pointed%20out%20earlier%20by%20bmike1%20in%20response%20to%20my%20comment%20about%20GRUB2%0A>%20>>%20not%20being%20able%20to%20find%20the%20OS%20if%20you%20move%20the%20partitions,%20by%20default%20on%0A>%20>>%20Linux%20Mint%20GRUB2%20will%20use%20UUIDs%20*(the%20id%20tag%20for%20your%20partitions)*%20instead%0A>%20>>%20of%20partition%20numbers*(eg:%20sda1,%20sda2,%20etc)*,%20so%20I%20was%20incorrect%20when%20I%0A>%20>>%20said%20GRUB2%20won't%20be%20able%20to%20find%20the%20boot%20partition.%20Linux%20Mint's%20fstab%20*(a%0A>%20>>%20config%20file%20read%20at%20boot%20to%20tell%20Mint%20which%20partitions%20should%20be%0A>%20>>%20automatically%20mounted)*%20also%20uses%20UUIDs%20by%20default%20so%20no%20issues%20there.%0A>%20>>%20Therefore%20I%20do%20not%20see%20any%20reason%20why%20moving%20your%20installation%20would%20be%20an%0A>%20>>%20issue%20*(keep%20reading)*,%20so%20I%20decided%20to%20test%20it%20in%20a%20virtual%20machine.%20I%0A>%20>>%20installed%20Linux%20Mint%2017.1%20-%20Cinnamon%2064bit%20*(I've%20been%20wanting%20to%20try%0A>%20>>%20Linux%20Mint%20for%20a%20while.%20I've%20been%20downloading%20a%20little%20bit%20of%20the%20ISO%20each%0A>%20>>%20day)*%20with%20a%20partition%20layout%20similar%20to%20yours%20*(http://i.imgur.com/3qg0bSv.png%0A>%20>>%20<http://i.imgur.com/3qg0bSv.png>%20)*.%20I%20wasn't%20able%20to%20move%20the%20extended%0A>%20>>%20partition%20using%20Gparted,%20or%20create%20a%20new%20one.%20In%20the%20end%20I%20just%20created%203%0A>%20>>%20new%20primary%20partitions%20and%20cloned%20the%20Linux%20Mint%20logical%20partitions%20to%20them%0A>%20>>%20using%20dd%20*(dd%20is%20a%20sector%20based%20cloning%20tool%20that%20comes%20pre-installed%20on%0A>%20>>%20most%20Linux%20operating%20systems.%20I%20used%20it%20because%20this%20way%20the%20new%20partitions%0A>%20>>%20will%20have%20the%20same%20UUIDS%20as%20the%20Linux%20Mint%20ones%20did.%20This%20is%20important%0A>%20>>%20since%20GRUB2%20is%20using%20UUIDS%20to%20identify%20the%20boot%20partition%20and%20because%20the%0A>%20>>%20fstab%20uses%20UUIDs%20to%20identify%20your%20swap%20partition)*.%20Then%20I%20deleted%20the%0A>%20>>%20old%20partitions%20*(%20http://i.imgur.com/hDBT5ns.png%0A>%20>>%20<http://i.imgur.com/hDBT5ns.png>%20)*.%20The%20result%20was%20that%20GRUB2%20was%0A>%20>>%20unable%20boot%20Linux%20Mint%20because%20it%20couldn't%20find%20the%20boot%20partition%20*(I%0A>%20>>%20don't%20know%20why%20this%20is,%20but%20if%20I%20had%20to%20take%20a%20guess%20it%20would%20be%20that%20GRUB2%0A>%20>>%20was%20probably%20storing%20part%20of%20itself%20on%20the%20extended%20partition's%20VBR%20which%0A>%20>>%20no%20longer%20exists%20because%20I%20deleted%20the%20extended%20partition)*.%20So%20GRUB2%0A>%20>>%20needed%20to%20be%20repaired.%20Using%20a%20Linux%20Mint%20Live-cd,%20I%20ran%20%22sudo%0A>%20>>%20add-apt-repository%20ppa:yannubuntu/boot-repair%22*(this%20adds%20a%20third%20party%0A>%20>>%20repo%20that%20has%20boot-repair%20in%20it,%20because%20it's%20not%20available%20in%20the%20default%0A>%20>>%20Linux%20Mint%20repos)*,%20%22sudo%20apt-get%20update%22%20*(to%20update%20apts%20package%20list)*,%0A>%20>>%20%22sudo%20apt-get%20install%20boot-repair%22%20*(to%20download%20and%20install%0A>%20>>%20boot-repair)*,%20and%20then%20I%20ran%20boot-repair%20with%20its%20default%20settings%20*(be%0A>%20>>%20warned%20by%20default%20boot-repair%20uploads%20information%20about%20your%20computer%0A>%20>>%20online,%20you%20can%20disable%20this)*.%20This%20successfully%20fixed%20GRUB2,%20and%20I%20was%0A>%20>>%20able%20to%20boot%20Linux%20Mint%20again%20*(http://i.imgur.com/ZJhXRbe.png%0A>%20>>%20<http://i.imgur.com/ZJhXRbe.png>%20)*.%0A>%20>>%0A>%20>>%20I%20then%20said:%0A>%20>>%0A>%20>>%20I%20think%20I%20know%20why%20it%20needed%20repairing.%20The%20reason%20is%20that%20you%20created%0A>%20>>%20new%20partitions%20(new%20UUIDs)%20and%20deleted%20the%20old%20partitions%20(the%20existing%0A>%20>>%20UUIDs).%0A>%20>>%0A>%20>>%20to%20which%20he%20responded:%0A>%20>>%0A>%20>>%20The%20partitions%20were%20cloned%20with%20dd%20so%20that%20they%20would%20have%20the%20same%0A>%20>>%20UUIDs.%20I%20also%20used%20%22sudo%20blkid%22%20to%20verify%20the%20uuids%20of%20the%20new%20primary%0A>%20>>%20partitions%20matched%20before%20deleting%20the%20original%20logical%20partitions.%0A>%20>>%0A>%20>>%20He%20and%20I%20both%20remarked%20between%20the%20first%20and%20last%20quote%20that%20we%20thought%0A>%20>>%20the%20UUID%20of%20the%20partition%20would%20of%20had%20it%20recognized%20regardless%20of%20what%20we%0A>%20>>%20did%20with%20other%20partitions%20on%20the%20drive.%20Could%20someone%20kindly%20explain%20to%20us%0A>%20>>%20wherein%20the%20difficulties%20lie?%0A>%20>>%20:-)~MIKE~(-:%0A>%20>>%0A>%20>%0A>%20>%0A>%20>%20---------------------------------------------------%0A>%20>%20PLUG-discuss%20mailing%20list%20-%20PLUG-discuss@lists.phxlinux.org%0A>%20>%20To%20subscribe,%20unsubscribe,%20or%20to%20change%20your%20mail%20settings:%0A>%20>%20http://lists.phxlinux.org/mailman/listinfo/plug-discuss%0A>%20>%0A>%20%0A>%20%0A>%20%0A>%20--%20%0A>%20James%20McPhee%0A>%20jmcphe@gmail.com%0A>%20---------------------------------------------------%0A>%20PLUG-discuss%20mailing%20list%20-%20PLUG-discuss@lists.phxlinux.org%0A>%20To%20subscribe,%20unsubscribe,%20or%20to%20change%20your%20mail%20settings:%0A>%20http://lists.phxlinux.org/mailman/listinfo/plug-discuss 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