Partitions and MBR
Partitions and MBR
When I use IFL to backup a disk with only one partition, and if I select the checkbox only for the partition to be backed up instead of the top checkbox for the whole drive, am I correct in saying that the boot sector of the partition would be backed up but the drive's MBR would not be backed up? Thanks.
-
TeraByte Support(TP)
- Posts: 305
- Joined: Wed Aug 31, 2011 4:22 pm
Re: Partitions and MBR
userX wrote:
> When I use IFL to backup a disk with only one partition, and if I select
> the checkbox only for the partition to be backed up instead of the top
> checkbox for the whole drive, am I correct in saying that the boot sector
> of the partition would be backed up but the drive's MBR would not be backed
> up? Thanks.
The boot sector of a parttiion is always backed up, since it is part of the partition.
When backing up an individual partition, the drive's first track (including the MBR) is always backed up with it, but it will not be restored when you restore that partition, unless you select the "Restore First Track" option on the restore options screen (see page 56 of the IFL manual).
> When I use IFL to backup a disk with only one partition, and if I select
> the checkbox only for the partition to be backed up instead of the top
> checkbox for the whole drive, am I correct in saying that the boot sector
> of the partition would be backed up but the drive's MBR would not be backed
> up? Thanks.
The boot sector of a parttiion is always backed up, since it is part of the partition.
When backing up an individual partition, the drive's first track (including the MBR) is always backed up with it, but it will not be restored when you restore that partition, unless you select the "Restore First Track" option on the restore options screen (see page 56 of the IFL manual).
Re: Partitions and MBR
On 2012-10-01 8:09 AM, TP wrote:
> userX wrote:
>> When I use IFL to backup a disk with only one partition, and if I select
>> the checkbox only for the partition to be backed up instead of the top
>> checkbox for the whole drive, am I correct in saying that the boot sector
>> of the partition would be backed up but the drive's MBR would not be backed
>> up? Thanks.
>
>
> The boot sector of a parttiion is always backed up, since it is part of the partition.
>
> When backing up an individual partition, the drive's first track (including the MBR) is always backed up with it, but it will not be restored when you restore that partition, unless you select the "Restore First Track" option on the restore options screen (see page 56 of the IFL manual).
>
>
Under what circumstances would you NOT want the first track restored
when restoring a partition?
AlanD
> userX wrote:
>> When I use IFL to backup a disk with only one partition, and if I select
>> the checkbox only for the partition to be backed up instead of the top
>> checkbox for the whole drive, am I correct in saying that the boot sector
>> of the partition would be backed up but the drive's MBR would not be backed
>> up? Thanks.
>
>
> The boot sector of a parttiion is always backed up, since it is part of the partition.
>
> When backing up an individual partition, the drive's first track (including the MBR) is always backed up with it, but it will not be restored when you restore that partition, unless you select the "Restore First Track" option on the restore options screen (see page 56 of the IFL manual).
>
>
Under what circumstances would you NOT want the first track restored
when restoring a partition?
AlanD
Re: Partitions and MBR
For example when you are restoring a single partition to free space of a drive containing many others partitions. Then you don't want to restore the MBR and the EMBR.
But if you are speaking about the first sector of the partition, then you should allways restore it.
But if you are speaking about the first sector of the partition, then you should allways restore it.
-
TeraByte Support(TP)
- Posts: 305
- Joined: Wed Aug 31, 2011 4:22 pm
Re: Partitions and MBR
AlanD wrote:
> Under what circumstances would you NOT want the first track restored
> when restoring a partition?
>
> AlanD
Needing to restore the first track when restoring a single partition is actually the exception, rather than the rule. IFL (or IFD or IFW) will take care of updating the MBR partition table (and/or EMBR if one exists) by default, when a partition is restored. Normally, that's all that needs to be done.
Unconditionally restoring the entire first track can cause problems in some situations. Just as one example, if the Grub boot loader code was installed in the first track of the drive that you created the image from, then restoring that partition (and the Grub first track with it) to a different drive, will overwrite whatever is in the first track of the new drive, which may very well not be desirable.
> Under what circumstances would you NOT want the first track restored
> when restoring a partition?
>
> AlanD
Needing to restore the first track when restoring a single partition is actually the exception, rather than the rule. IFL (or IFD or IFW) will take care of updating the MBR partition table (and/or EMBR if one exists) by default, when a partition is restored. Normally, that's all that needs to be done.
Unconditionally restoring the entire first track can cause problems in some situations. Just as one example, if the Grub boot loader code was installed in the first track of the drive that you created the image from, then restoring that partition (and the Grub first track with it) to a different drive, will overwrite whatever is in the first track of the new drive, which may very well not be desirable.
Re: Partitions and MBR
Tom, hello.
I am still a little confused about what would happen to the MBR under a specific scenario. My goal would be to have backups that would allow me to restore either of two ways. First, I might want to restore my system to its initial condition of having only one partition, which, for example, would only partially fill the disk, that is, leaving still unallocated space initially. Secondly, I might want to restore my system to whatever condition it has at some point in time, which, for example, could have several partitions.
If I have made a backup of the whole drive initially, which in this case consisted of only one partition, and let's say that the partition only partially filled this disk, then my MBR that also backed up along with it would reflect only one partition being present. Now if I later added other partitions to this drive without making additional changes to the first partition, and I then made corresponding backups of the additional partitions but excluded the first partition, based on my understanding of what you said, these later backups would have a MBR backed up with them corresponding to a disk with several partions, unlike my original backup data when only one partition existed.
Now, if I at some point wanted to restore everything, it seems to me that it would be necessary for me to be careful about the order in which I restored these partitions. I mean, since the very first partition's backup occurred when it was the only one present, then it would have backed up with a MBR reflecting only one partition. However, if I started restoring several partitions individually, each time I restore one of them I would likewise restore the MBR that existed at the time it was backed up. So, if I restored the first partition after restoring the others, the MBR restored along with it would not really reflect the existence of these other partitions because they did not exist when I made the backup of this first partition. How does this sort of problem get resolved? I mean, how does one avoid it?
I am still a little confused about what would happen to the MBR under a specific scenario. My goal would be to have backups that would allow me to restore either of two ways. First, I might want to restore my system to its initial condition of having only one partition, which, for example, would only partially fill the disk, that is, leaving still unallocated space initially. Secondly, I might want to restore my system to whatever condition it has at some point in time, which, for example, could have several partitions.
If I have made a backup of the whole drive initially, which in this case consisted of only one partition, and let's say that the partition only partially filled this disk, then my MBR that also backed up along with it would reflect only one partition being present. Now if I later added other partitions to this drive without making additional changes to the first partition, and I then made corresponding backups of the additional partitions but excluded the first partition, based on my understanding of what you said, these later backups would have a MBR backed up with them corresponding to a disk with several partions, unlike my original backup data when only one partition existed.
Now, if I at some point wanted to restore everything, it seems to me that it would be necessary for me to be careful about the order in which I restored these partitions. I mean, since the very first partition's backup occurred when it was the only one present, then it would have backed up with a MBR reflecting only one partition. However, if I started restoring several partitions individually, each time I restore one of them I would likewise restore the MBR that existed at the time it was backed up. So, if I restored the first partition after restoring the others, the MBR restored along with it would not really reflect the existence of these other partitions because they did not exist when I made the backup of this first partition. How does this sort of problem get resolved? I mean, how does one avoid it?
-
Bob Coleman
- Posts: 786
- Joined: Fri Aug 12, 2011 5:58 pm
Re: Partitions and MBR
To userX:
I don't actually know any more about this than you do, but I think Tom said that even though the first track containing the MBR would be backed up with each partition, it would NOT be restored with the partition when a single partition is restored unless restoring of the MBR is explicitly requested via the "Restore First Track" option. He also said that the MBR would be updated as necessary when a partition is restored (update, not restored). I interpret that to mean that you can restore the partitions in whatever order you want since the MBR will not be restored with the partition.
Read Tom's response again and see if you don't come to the same conclusion.
I don't actually know any more about this than you do, but I think Tom said that even though the first track containing the MBR would be backed up with each partition, it would NOT be restored with the partition when a single partition is restored unless restoring of the MBR is explicitly requested via the "Restore First Track" option. He also said that the MBR would be updated as necessary when a partition is restored (update, not restored). I interpret that to mean that you can restore the partitions in whatever order you want since the MBR will not be restored with the partition.
Read Tom's response again and see if you don't come to the same conclusion.
-
TeraByte Support(TP)
- Posts: 305
- Joined: Wed Aug 31, 2011 4:22 pm
Re: Partitions and MBR
userX wrote:
> Tom, hello.
>
> I am still a little confused about what would happen to the MBR under a
> specific scenario. My goal would be to have backups that would allow me to
> restore either of two ways. First, I might want to restore my system to its
> initial condition of having only one partition, which, for example, would
> only partially fill the disk, that is, leaving still unallocated space
> initially. Secondly, I might want to restore my system to whatever
> condition it has at some point in time, which, for example, could have
> several partitions.
>
> If I have made a backup of the whole drive initially, which in this case
> consisted of only one partition, and let's say that the partition only
> partially filled this disk, then my MBR that also backed up along with it
> would reflect only one partition being present. Now if I later added other
> partitions to this drive without making additional changes to the first
> partition, and I then made corresponding backups of the additional
> partitions but excluded the first partition, based on my understanding of
> what you said, these later backups would have a MBR backed up with them
> corresponding to a disk with several partions, unlike my original backup
> data when only one partition existed.
>
> Now, if I at some point wanted to restore everything, it seems to me that
> it would be necessary for me to be careful about the order in which I
> restored these partitions. I mean, since the very first partition's backup
> occurred when it was the only one present, then it would have backed up
> with a MBR reflecting only one partition. However, if I started restoring
> several partitions individually, each time I restore one of them I would
> likewise restore the MBR that existed at the time it was backed up. So, if
> I restored the first partition after restoring the others, the MBR restored
> along with it would not really reflect the existence of these other
> partitions because they did not exist when I made the backup of this first
> partition. How does this sort of problem get resolved? I mean, how does
> one avoid it?
The order of restore wouldn't be a problem for 2 reasons:
1. As long as you don't select the "Restore First Track" option , the first track won't be restored when you restore any individual partition(s).
2. Even when selected, the "Restore First Track" option will only restore the code portion of the MBR/first track. It will not replace the partition table with some previous partition table that is no longer valid. The partition table will be kept valid, and will correspond to the partitions currently on the disk - the same as it would do if you hadn't selected the "Restore First Track" option.
When you restore an image of an entire drive, that's a different story. In that case, by definiton, you want to restore the entire drive, including all partitions as they were on the source drive,, as well as the MBR/first track.
> Tom, hello.
>
> I am still a little confused about what would happen to the MBR under a
> specific scenario. My goal would be to have backups that would allow me to
> restore either of two ways. First, I might want to restore my system to its
> initial condition of having only one partition, which, for example, would
> only partially fill the disk, that is, leaving still unallocated space
> initially. Secondly, I might want to restore my system to whatever
> condition it has at some point in time, which, for example, could have
> several partitions.
>
> If I have made a backup of the whole drive initially, which in this case
> consisted of only one partition, and let's say that the partition only
> partially filled this disk, then my MBR that also backed up along with it
> would reflect only one partition being present. Now if I later added other
> partitions to this drive without making additional changes to the first
> partition, and I then made corresponding backups of the additional
> partitions but excluded the first partition, based on my understanding of
> what you said, these later backups would have a MBR backed up with them
> corresponding to a disk with several partions, unlike my original backup
> data when only one partition existed.
>
> Now, if I at some point wanted to restore everything, it seems to me that
> it would be necessary for me to be careful about the order in which I
> restored these partitions. I mean, since the very first partition's backup
> occurred when it was the only one present, then it would have backed up
> with a MBR reflecting only one partition. However, if I started restoring
> several partitions individually, each time I restore one of them I would
> likewise restore the MBR that existed at the time it was backed up. So, if
> I restored the first partition after restoring the others, the MBR restored
> along with it would not really reflect the existence of these other
> partitions because they did not exist when I made the backup of this first
> partition. How does this sort of problem get resolved? I mean, how does
> one avoid it?
The order of restore wouldn't be a problem for 2 reasons:
1. As long as you don't select the "Restore First Track" option , the first track won't be restored when you restore any individual partition(s).
2. Even when selected, the "Restore First Track" option will only restore the code portion of the MBR/first track. It will not replace the partition table with some previous partition table that is no longer valid. The partition table will be kept valid, and will correspond to the partitions currently on the disk - the same as it would do if you hadn't selected the "Restore First Track" option.
When you restore an image of an entire drive, that's a different story. In that case, by definiton, you want to restore the entire drive, including all partitions as they were on the source drive,, as well as the MBR/first track.
Re: Partitions and MBR
On 2012-10-02 9:12 AM, TP wrote:
> userX wrote:
>> Tom, hello.
>>
>> I am still a little confused about what would happen to the MBR under a
>> specific scenario. My goal would be to have backups that would allow me to
>> restore either of two ways. First, I might want to restore my system to its
>> initial condition of having only one partition, which, for example, would
>> only partially fill the disk, that is, leaving still unallocated space
>> initially. Secondly, I might want to restore my system to whatever
>> condition it has at some point in time, which, for example, could have
>> several partitions.
>>
>> If I have made a backup of the whole drive initially, which in this case
>> consisted of only one partition, and let's say that the partition only
>> partially filled this disk, then my MBR that also backed up along with it
>> would reflect only one partition being present. Now if I later added other
>> partitions to this drive without making additional changes to the first
>> partition, and I then made corresponding backups of the additional
>> partitions but excluded the first partition, based on my understanding of
>> what you said, these later backups would have a MBR backed up with them
>> corresponding to a disk with several partions, unlike my original backup
>> data when only one partition existed.
>>
>> Now, if I at some point wanted to restore everything, it seems to me that
>> it would be necessary for me to be careful about the order in which I
>> restored these partitions. I mean, since the very first partition's backup
>> occurred when it was the only one present, then it would have backed up
>> with a MBR reflecting only one partition. However, if I started restoring
>> several partitions individually, each time I restore one of them I would
>> likewise restore the MBR that existed at the time it was backed up. So, if
>> I restored the first partition after restoring the others, the MBR restored
>> along with it would not really reflect the existence of these other
>> partitions because they did not exist when I made the backup of this first
>> partition. How does this sort of problem get resolved? I mean, how does
>> one avoid it?
>
> The order of restore wouldn't be a problem for 2 reasons:
>
> 1. As long as you don't select the "Restore First Track" option , the first track won't be restored when you restore any individual partition(s).
>
> 2. Even when selected, the "Restore First Track" option will only restore the code portion of the MBR/first track. It will not replace the partition table with some previous partition table that is no longer valid. The partition table will be kept valid, and will correspond to the partitions currently on the disk - the same as it would do if you hadn't selected the "Restore First Track" option.
>
> When you restore an image of an entire drive, that's a different story. In that case, by definiton, you want to restore the entire drive, including all partitions as they were on the source drive,, as well as the MBR/first track.
>
>
Regards last paragraph above: just to be clear (for my sake), since I
always image and therefore restore whole drives, I should select
"restore first track"; however, here is a large ? I know longer find
the option to select "Restore First Track" in the option list when I
walked through IFW Backup(Full). Threfore I am confused.
AlanD
> userX wrote:
>> Tom, hello.
>>
>> I am still a little confused about what would happen to the MBR under a
>> specific scenario. My goal would be to have backups that would allow me to
>> restore either of two ways. First, I might want to restore my system to its
>> initial condition of having only one partition, which, for example, would
>> only partially fill the disk, that is, leaving still unallocated space
>> initially. Secondly, I might want to restore my system to whatever
>> condition it has at some point in time, which, for example, could have
>> several partitions.
>>
>> If I have made a backup of the whole drive initially, which in this case
>> consisted of only one partition, and let's say that the partition only
>> partially filled this disk, then my MBR that also backed up along with it
>> would reflect only one partition being present. Now if I later added other
>> partitions to this drive without making additional changes to the first
>> partition, and I then made corresponding backups of the additional
>> partitions but excluded the first partition, based on my understanding of
>> what you said, these later backups would have a MBR backed up with them
>> corresponding to a disk with several partions, unlike my original backup
>> data when only one partition existed.
>>
>> Now, if I at some point wanted to restore everything, it seems to me that
>> it would be necessary for me to be careful about the order in which I
>> restored these partitions. I mean, since the very first partition's backup
>> occurred when it was the only one present, then it would have backed up
>> with a MBR reflecting only one partition. However, if I started restoring
>> several partitions individually, each time I restore one of them I would
>> likewise restore the MBR that existed at the time it was backed up. So, if
>> I restored the first partition after restoring the others, the MBR restored
>> along with it would not really reflect the existence of these other
>> partitions because they did not exist when I made the backup of this first
>> partition. How does this sort of problem get resolved? I mean, how does
>> one avoid it?
>
> The order of restore wouldn't be a problem for 2 reasons:
>
> 1. As long as you don't select the "Restore First Track" option , the first track won't be restored when you restore any individual partition(s).
>
> 2. Even when selected, the "Restore First Track" option will only restore the code portion of the MBR/first track. It will not replace the partition table with some previous partition table that is no longer valid. The partition table will be kept valid, and will correspond to the partitions currently on the disk - the same as it would do if you hadn't selected the "Restore First Track" option.
>
> When you restore an image of an entire drive, that's a different story. In that case, by definiton, you want to restore the entire drive, including all partitions as they were on the source drive,, as well as the MBR/first track.
>
>
Regards last paragraph above: just to be clear (for my sake), since I
always image and therefore restore whole drives, I should select
"restore first track"; however, here is a large ? I know longer find
the option to select "Restore First Track" in the option list when I
walked through IFW Backup(Full). Threfore I am confused.
AlanD
-
TeraByte Support(TP)
- Posts: 305
- Joined: Wed Aug 31, 2011 4:22 pm
Re: Partitions and MBR
AlanD wrote:
> > When you restore an image of an entire drive, that's a different story.
> In that case, by definiton, you want to restore the entire drive, including
> all partitions as they were on the source drive,, as well as the MBR/first
> track.
> >
> >
> Regards last paragraph above: just to be clear (for my sake), since I
> always image and therefore restore whole drives, I should select
> "restore first track"; however, here is a large ? I know longer find
> the option to select "Restore First Track" in the option list when I
> walked through IFW Backup(Full). Threfore I am confused.
Right, that option isn't there when restoring an entire drive, because the first track is always restored in that situation. I should have clarified that.
> > When you restore an image of an entire drive, that's a different story.
> In that case, by definiton, you want to restore the entire drive, including
> all partitions as they were on the source drive,, as well as the MBR/first
> track.
> >
> >
> Regards last paragraph above: just to be clear (for my sake), since I
> always image and therefore restore whole drives, I should select
> "restore first track"; however, here is a large ? I know longer find
> the option to select "Restore First Track" in the option list when I
> walked through IFW Backup(Full). Threfore I am confused.
Right, that option isn't there when restoring an entire drive, because the first track is always restored in that situation. I should have clarified that.