Need Help With 2 USB Drives for Backup

Discussion in 'Acronis True Image Product Line' started by TFVersion1, Jun 5, 2006.

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  1. TFVersion1

    TFVersion1 Registered Member

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    Ok here's what I'd like to do now that I understand it a bit more.
    Sorry if its a bit long... anyone's help is appreciated. May seem simple but read on..

    Desired:
    Have 2 alternating USB drives for backup targets - one will always be offsite.
    Create a Full image, once every 2 weeks with Diffs in between.
    Swap the USB drives out every 2 weeks resulting in
    1 Full and 11 Diffs on each USB drive. i.e 2 weeks worth on each.
    Every 2 weeks I'd like it to start over - not accumuate so not to fill up the drives.
    This way:
    - I can go back 2 weeks for recovery
    - one drive will always have a backup set in case the other dies
    - or the servers blowup in the middle of backing up to a usb drive.
    - And keeps insurance happy!

    sidenote: I don't think going incremental is wise because what if one of them (an incr. file) is bad? Then recovery will fail. Differential takes more space but space is cheap - I think its worth it. And one can use any Diff file with its Full parent. Is this a fair statement?

    Proposed plan:

    Any month...

    Using USB drive 1...
    Week 1 - Mon is Full backup
    Week 1 - T, W, Th, F, Sat is Diff.
    Week 2 - NO new Full. M, T, W, Th, F, Sat is Diff.


    Using USB drive 2...
    Week 3 - Mon is Full backup
    Week 3 - T, W, Th, F, Sat is Diff.
    Week 4 - NO new Full. M, T, W, Th, F, Sat is Diff.

    Then back to USB-1 for next month. Fair enuf?

    So, after the first month, I would have 1 Full backup image for 11 Diffs on each USB drive.
    Here's what I'm not sure of:
    1. In the first month, USB-2 is exchanged for USB-1 on week 3 as normal before the Monday; USB-2 drive is empty so, a new Full image is created on the Monday and new Diffs are created and so on. ok this should work right?

    2. What happens at the start of the 2nd month when USB-1 is put back?
    Can the scheduling handle the fact that for instance, USB-1 has been "away" for 2 weeks? Will it be "remembered"?
    Will Acronis be confused or continue (as desired) and overwrite the Full backup with a new one and Diff overwrite the diffs etc?
    Again, I don't want Acronis to create new image files and fill up the drive

    Lastly.... sorry to be long winded... but I don't want to try this if it won't work.. no time!
    - If for instance, USB-2 was forgotten about and USB-1 were left connected for the entire month or more; I need to be sure that the Full image will overwrite itself every 2 weeks and same for the Diffs every week - so the drive doesn't fill up. i.e. it won't be disaterous if the drive swap is forgotten.

    Hope this is not too complicated...

    If the acculated space from the Diffs proves to be too big, I can probably reduce it to every second day for Diffs. The main thing is to have 2 drives in the plan with one always offsite.

    Thanks for you patience and assistance.
     
  2. TheWeaz

    TheWeaz Registered Member

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    Well, reading that gave me a headache :D , but let’s throw out this idea.
    If you have a task to create a DIFF image named BACKUP and there is no FULL image at the target named BACKUP, TI will create a FULL image instead. So …

    Create a DIFF task, scheduled to run Mon-Sat. You attach drive 1 (no files on it). The first time the task runs, a FULL gets created (see above). Then, each time it runs after that, a DIFF gets created based on the FULL.
    At the end of the 2 weeks, switch to drive 2 (also empty) and the same set of events will occur. If you forget to switch, TI will keep creating additional DIFFs on drive 1 until you run out of space. It would then issue an error message.
    When you switch back to drive 1, all the images on it will need to be deleted. If you do not delete them, TI will just start adding more DIFF images.

    This may be the simplest solution – you will just have to remember to delete all the images from the drive about to be reattached.

    I’m sure others may come up with something but my head still hurts … o_O
     
  3. computergeek2

    computergeek2 Registered Member

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    The simplest way is to get two large 2.0 usb dirves and make a full backup of your computer. When one USB external drive is full, switch to the other and erase the first drive. The problem is that the incremental backups take almost as much room as the full backups. If you make the full backup image while you are in the windows mode it will go very fast. Using the Acronis cd backup disc to make a backup image takes about 3 times as long as doing in within the windows environment.
     
  4. Xpilot

    Xpilot Registered Member

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    Well done The Weaze for getting your head round the OP's proposal. No wonder it hurts!
    I do however question why it is a good idea to rotate the USB drives only every two weeks. This means in a worst case where the installed drive and the on site external drive both failed the best recovery that might be available could be fifteen days old. I would go for a daily rotation of the external drives so in the worst case the recoverable image would only be three days old. To take this one stage further why rotate the external drives at all. One could backup to an on site drive and either copy or make a second backup to the off site drive. The worst case scenario then looks much better as only one day's changes would be lost. I tend to look at a backup scheme from the point of view of what is the maximum amount of data and changes that I would be prepared to lose not how many backups I can squeeze out of the system.

    Xpilot
     
  5. TheWeaz

    TheWeaz Registered Member

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    The OP (and anyone in this situation) really needs to be sure their needs are fully defined.
    Is off-site storage really needed? In some cases it may be required.
    How far back would one want to be able to restore? We have tapes at work that are kept for 5 years.
    How many days of data could you afford to lose? As Xpilot said, this scheme could leave you without the last 15 days.
    That’s why this type of question is always difficult to answer.

    From one of my previous posts:

    “I have 9 scheduled tasks, all Full images.
    One each for the 1st, 8th, 15th, 22nd and 29th.
    A Weekly each Sunday.
    Then three more, one each on Mon & Thu, Tue & Fri and Wed & Sat.
    Once these 9 images are created, they just cycle through and get written over.”

    These are all created on an internal drive dedicated for backups. I copy the Weekly ones to an external USB.
     
  6. TFVersion1

    TFVersion1 Registered Member

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    Thanks for the replies guys. ( and c'mon it wasn't that complicated a scenario) ;)
    OK (from the OP). Here's why I made this proposal. I am seeking a solution for a client for his backup needs. He, like most I would venture to say, needs to have this task made fairly simple - No having to copy the drive contents to some other location at some point in time, etc. They're business owners - KISS - we're the IT guys to make it simple for them...

    So the backup needs are nothing special other than being able to restore data and O/S from a "reasonable" period in the past. We decided that 2 weeks is fine.

    #1. The question from one of you guys asked about why use 2 drives at all?
    Consider this: If only one drive is used - On any given time in the middle of a full backup, what if the server or usb drive craps out badly at this point and the job is incomplete?
    With one backup drive, THAT full image is the only one you have at this time and now its likely corrupt and useless. Unless one does PRE cmds to copy and rename before new Full etc. But that's a different story. Even then, for the low cost, I would still feel better to have a known good second copy elsewhere - On the second drive, the Full image is the only 2 weeks old, and presumably, the Diffs are there right up until the server or usb drive crash mentioned above. So I don't see an issue here with 2, But I do with 1 drive.


    Also, the client's insurance policy asks that backups be offsite. Don't most? This is nothing unusual I'm sure. So 2 usb drives is a cheap solution. Its risk management.

    #2. Overwriting image files.
    Unless I misunderstood, I thought from reading various posts etc, that if you setup a given rotation period, the images are available for overwrite at the end of the rotation. So, because the images would be the same name, the next Full backup, when the rotation starts from beginning again, overwrites the Full on the target drive, the Diff overwrites the Diff etc. - kinda like what we do with tapes - ie. backup jobs on tapes have a certain overwrite protection time after which, when you reuse them, the backup job just overwrite what's there. i.e. Backup Exec. But you're saying that Acronis just keeps on creating Diffs until the space runs.. Hmmm..well that kinda sucks.
    There were some posts that talked about "I will only ever have 7 or 8 images on the drive..." I thought this was what they were talking about. Its pointless to me ( the client ) if you have to manage that manually.

    The Security Zone does this kinda thing
    http://www.acronis.com/homecomputing/resource/solutions/backup/2005/secure-zone.html
    Why couldn't the backups to other media do similar?
    Thanks
     
  7. TFVersion1

    TFVersion1 Registered Member

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    What do you mean, "Once these 9 images are created, they just cycle through and get written over.”.. Is this done manually or automatically?
     
  8. Xpilot

    Xpilot Registered Member

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    I am glad you have mentioned the secure zone. It is a feature of Acronis true image that I use on a daily basis. I do not keep it on the main drive that is being backed up but on a separate slave drive.
    The way it works for me is entirely automatic. I have a one line task to backup the main drive every day. The size of the drive is such that I have 10 days of backups which the system manages on the FIFO basis. The Joy of this method is that once set up no user intervention is needed at all. The backups are run in the Windows environment, no re-booting is needed and if desired the system can continue to be used while the backup process is running.
    I use the above as my first line of defence. For additional security I run separate backups to a USB hard drive. Again this is a one line task which could be run automatically though I actually manage the external drive manually.
    So that is my version of the KISS principle which works for me.
    The last stage is to actually test the backup system by simulating a failure and carrying out an actual restore. The riskless method I use is to take out the main drive and replace it with a spare. Then boot from the True Image recovery disk and restore from each backup source in turn.

    Xpilot
     
  9. TheWeaz

    TheWeaz Registered Member

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    Automatically.
     
  10. crofttk

    crofttk Registered Member

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    Not unless you have moved around large amounts of hard drive sectors with something like defragmenting or done something that makes ATI think almost all of the sectors have been changed somehow.
     
  11. TFVersion1

    TFVersion1 Registered Member

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    If you're backing up primarily database files, esp large ones, and you touch them, then your incr backups will be almost same size as full
     
  12. TheWeaz

    TheWeaz Registered Member

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    "Once these 9 images are created, they just cycle through and get written over.”..
    “Overwriting image files”
    If you run a FULL image task and a file with the same name you give the image already exists on the target, TI will overwrite.
    So if you run a FULL with the image name BACKUP on Monday and then again on Tuesday, the Monday file will be overwritten on Tuesday.
     
  13. TFVersion1

    TFVersion1 Registered Member

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    Right. That's how I understood it.
    So will that happen with subsequent Diffs as well?
    i.e. Assuming that BACKUP1, BACKUP2, etc, exist as well on the drive.
    Will they be overwritten? If so, then that's it! That's the answer I'm looking for and it'll be a self-managed system.
     
  14. TheWeaz

    TheWeaz Registered Member

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    DIFF/INCs will only overwrite themselves * IF * the FULL on which they are based has been overwritten. Otherwise, they will just create the next image in the set.
     
  15. crofttk

    crofttk Registered Member

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    Ooops ! Either I missed where you said that or computergeek2 is psychic !:D In any event, I guess that would make "ATI think almost all of the sectors have been changed somehow".
     
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