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SSR and RAW disk blocks

Created: 28 Nov 2012 • Updated: 30 Nov 2012 | 7 comments
RLeon's picture
This issue has been solved. See solution.

Hi all,

I am in the process of evaluating whether to go for SSR or another similar solution from a certain vendor, for one of our projects.
Hot cloning is not important, it is the cold cloning capabilities that will be the deciding factor.
(Cold cloning, a.k.a., Cold Backup, Offline Backup, Offline Disk Cloning, Offline Disk Imaging, etc.)

I have tested both evaluation versions, and have found that SSR could not backup RAW disk blocks, while the other solution could.
After booting up the host with the SSR boot CD, I found that it only allows me to select parts of the disk that actually contain a file system.
Either that, or it only allows me to select the parts that have a MBR/GPT header.
In other words, the remaining RAW parts of the disk cannot be backed up.

The other vendor's solution, on the other hand, lets me backup the entire disk, block by block, blindly, regardless of whether file systems or partitions could be identified at all.

I could understand that, by identifying file systems, it allows for "smart" backing up of blocks that actually contain files, skipping the rest of the disk that don't, and as a result, helping to speed up the backup process and saving storage space.
But the capability to backup RAW blocks is also very important.

I would like to know if I have missed some settings somewhere with SSR.
Can it be configured to also backup RAW disk blocks?

Thanks for your help.

 

Addtional information about "RAW" disk blocks:
Some refer to them as RAW partitions, RAW volumes, RAW disks, RAW data, unallocated partition, random blocks, noise data, etc.
It is part of the disk that does not contain any files, file systems or MBR/GPT partition headers.
So basically no FAT, no NTFS, no ext3, no OS, no boot partition, no data, nothing.

As an example, if you have a 100GB disk, and you partition the first 60GB to be NTFS, and then do nothing with the remaining 40GB, then in Windows Disk Management, that remaining 40GB will be identified as "Unallocated". To Windows, this is a RAW partition.
(Using this example, I found that SSR would only allow me to select the first 60GB to backup. I couldn't see the remaining 40GB anywhere in the GUI for me to select.)

Some DB applications such as Oracle, and encryption applications such as TrueCrypt, write data to RAW disk blocks.
Some home PC brands also store their recovery system in RAW partitions on a disk.
 

Comments 7 CommentsJump to latest comment

Markus Koestler's picture

According to the USers guide http://www.symantec.com/business/support/index?pag... page 26 SSR only supports

■FAT16, FAT16X
■ FAT32, FAT32X
■ NTFS
■ GUID partition table (GPT)
■ Dynamic disks
■ Linux Ext2, Linux Ext3
■ Linux swap partitions

 

But let me raise this question to support for you, maybe they can answer it very quickly.

*** Please mark thread as solved if you consider this to have answered your question(s) ***

RLeon's picture

Hi Markus,

I've gone through that part of the SSR guide too.
I was afraid that the non-existence of "RAW partition" on that list means it is not supported, but I have no way of confirming. (Well I did test it, and indeed it cannot be backed up.)

But then again, the list also doesn't have "MBR partition", and SSR backs up MBR partitions just fine.
The list is also called a "file systems" list, but it has things like GPT and Dynamic Disks as entries... indecision
Maybe I'm thinking too deep into this "list".

If I remember correctly, even very old versions of Norton Ghost supported imaging/cloning RAW partitions.

I appreciate your help in trying to get the answer.

Thanks,

RLeon

Chris Riley's picture

I'm fairly sure (although will need to check and confirm) that you cannot do this with the current version of the product.

Some questions:

  1. What are your specific requirements for the project you mention that means you need to backup RAW disks? I know you have mentioned Oracle etc write to these disks but I would like to understand your specific requirements in this area.
  2. Are you able to share details of the other vendor that has this functionality?

Once I have your replies, I will take this up with our Product Management and Engineering teams.

RLeon's picture

Hi Chris,

Thanks for your input.

As you have pointed out, my examples where protecting RAW disk blocks is important are all valid scenarios.

The one I am involved in, there are some PCs with encrypted partitions that are to be image/block level backed up manually and periodically, offline.
The requirement is that the resulting image must be block-perfect of the entire disk device.
It other words, the solution must blindly and perfectly copy every single bit and block off the disk during an offline backup, which includes bits and blocks it could not "understand".

As for a product.... Let's stick with Norton Ghost. I'm pretty sure it could do exact that. I haven't used any of the newer versions since the Windows 98 days, so I don't know if the newer versions could still do the same.

Please refer to the following documentations for more information about such encrypted volumes. (Although TrueCrypt is not the only example...)
  http://www.truecrypt.org/docs/?s=truecrypt-volume
You may want to skip the parts about the file-host (emulated) encrypted volumes because those are not relevant.

Thanks for your help,

RLeon

Chris Riley's picture

I've raised this subject internally for discussion.

I will get back to you when I have some news on this. Hopefully within the next day or so.

Chris Riley's picture

Update...

I have discussed this internally and unfortunately the current version of the product does not support this. In order to do a cold backup, a partition must exist.

This is now being looked at for a future version of the product but it's too early to say when this functionality will be available.

Hope this helps.

SOLUTION
RLeon's picture

Thank you both for helping to clear that up.