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  1. #1
    Join Date
    May 2002
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    My analysis on Windows Servers Backup solutions and a couple questions

    After suffering a complete hard drive failure early last week on my SM P2.4 server (almost 2 years old) and having to recover everything from my daily backups (had about 6 hours of server downtime and another couple hours to install and restore settings as they were before) I started analyzing all my options to decrease downtime in case a similar failure occurs in the future since hard drives are what can cause the server's greater downtime and headaches.

    Here are my findings and comments/ideas so far.

    At first I looked at disk image creation programs. I tested Acronis True Image and also looked at a similar offering from Norton.

    Acronis True Image is indeed a very very nice piece of software. It creates an image of one or more partitions (or your entire drive) right from windows without any reboot required. An image of a 3 Gb partition took about 2 minutes to complete and the image was about 1 Gb in size. The next backups can be done incrementally so that only changed blocks are read and saved (100 Mb on a day for my test). You can also restore partitions right from Windows and mount images as drives to explore the contents. Very neat.
    Only one problem. To restore the OS partition you have to do it from a loader that runs starts right before the OS restarts and there's no way to automate the restore process. So there's a need to actually select "Restore Image", pick the file, select the restore options and the destination place. It's very straightforward but I would need a TP tech to manually do it in case of a restore was needed.

    I started looking for alternatives and found the following program that, from the description, offers all that I need: TransXP - http://www.itechs-systems.com/. It creates an exact image of a drive to a second one, fully bootable, so it only a mater of swapping one for the other and you have the computer up and running again. There isn't a demo available so I've contacted the company and I'm waiting for an answer.
    If this works out I can have it run every day at night to keep an exact copy of the first one and in case of a failure simply include a note on orbit to exchange the drives if a failure occurs. It's like a mini RAID like but only running once a day and only copying the changed blocks.

    Of course, I also looked at the best option. RAID. Since TP offers are way more pricey compared with the server I got ($100 more/month - a raid setup starts at $300), I decided to go with the dual hard drives setup for now.

    I know I can do RAID 1 via software on Windows 2003 but I'm not very keen on converting the hardrives to the dynamic format and there's probably a noticeable hit on performance.

    So, what do you Windows Server guys use for downtime minimization and do you guys know of similar programs that offer the same features as TransXP?

    (If you've read until here I really must have gotten your attention! )
    Steven Martins

  2. #2
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  3. #3
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    Originally posted by jt2377
    TP's disksync
    DiskSync to me is a backup solution. If the primary hard drive fails then you are at least going to be 4 ou 5 hours offline for the drive replacement and OS reload.

    I'm looking at ways to simply swap the hard drive and be up and running again.
    Steven Martins

  4. #4
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    Apr 2005
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    although you may not want to hear it your best solution is raid, the money you'll spend on software and backups solutions could most likely get you a nice small raid-5 setup, (3x160 s-ata + 3ware)

  5. #5
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    Well, a RAID setup is going to set me back an extra $100/month, $1200/year so if I go with a software solution that really works it will be cost efective. This of course until I can justify the $100/extra month. I'm not trying to find a similar solution to hardware RAID because there is none.

    RAID 1 would be my choice because I only need a fail-safe solution. If a disk fails the computer will continue working until the faulty disk is replaced.

    I'm looking into another solution other than RAID 1 via software because I'm not very keen on converting the disks to the dynamic format and because it probably slows things down a little.
    Steven Martins

  6. #6
    Join Date
    Jul 2002
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    Originally posted by smartins
    Well, a RAID setup is going to set me back an extra $100/month, $1200/year so if I go with a software solution that really works it will be cost efective. This of course until I can justify the $100/extra month. I'm not trying to find a similar solution to hardware RAID because there is none.

    RAID 1 would be my choice because I only need a fail-safe solution. If a disk fails the computer will continue working until the faulty disk is replaced.

    I'm looking into another solution other than RAID 1 via software because I'm not very keen on converting the disks to the dynamic format and because it probably slows things down a little.
    how about colo? build/buy a server with RAID and colo it. have tech at colo to swap out hd if something happen.

  7. #7
    Join Date
    May 2002
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    Ok, that TransXP software solution is not very good. It's out of the question.

    So now I'm at either a P4 2.8 with hardware RAID or a Dual Xeon 2.8 with Dynamic Drives in a OS mirrored (RAID 1) mode.

    I've been giving some reading about Dynamic Disks and Mirroring and found this piece of information:

    "Although software-based RAID 1 mirrored volumes created under Win2K and NT provide redundancy by duplicating the contents of a primary disk to a shadow disk, these mirrored volumes don't duplicate the MBR. However, most hardware-based RAID solutions (e.g., RAID con-troller cards) mirror a basic disk's entire contents, including the MBR. This fact is one of many reasons why hardware RAID solutions are preferable to Win2K and NT's software-based RAID offerings."

    Anyone had any problem where one of the disks failed? I'm not sure about this information about the MBR but it came from an WindowsITPro.com article.
    Steven Martins

  8. #8
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    I've just been doing some more reading and found this:

    From my personal experience. They are not directly bootable by default. You have to issue a command to make the second drive bootable using the boot cds

    Also, whenever you have a crash (ie not a proper shutdown). The system resyncs the mirrors during which time the entire performance of the server becomes very sluggish. And do take note that the resync can take hours depending on your setup
    So, anyone that is currently using Dynamic Disks and Mirroring (RAID 1) via Windows 2003 can share your experiences about these comments?

    Thanks!
    Steven Martins

  9. #9
    Join Date
    Jul 2003
    Location
    Texas
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    785
    Try taking a look at the built in 'Windows Backup' tool that is available under the start menu 'System Tools'. You can use it to do a full 'System State' backup and of all your data files. This will backup all your software installed on the host along with user and other settings and the complete registry.

    This will all dump into a single compressed file which you can then verify is not corrupt and move it via ftp/scp/rsync/etc off to a remote host. Once your host fails down the road all you then need to do is have a basic OS re-install down then have the server networked and pull the file back down to run the restore application. After the restore is completed you will need to reboot the host and might have to reset a few changes in your IP/Network settings or applications but for the most part it should all be there exactly as you had it prior to the crash.

    The software is written by 'Veritas' and licensed to MS and should be installed on any host with Windows 2000 or higher. Completely free and dead easy to use. You can also have it dump the data to a network share if you do not want to mess around with ftp or other applications to move the data.

    The only issues I have had with it is when you move the data to a newer hardware which runs with device different drivers and or motherboard chipsets. The data will be restored properly but due to the driver issues it can cause stability problems.

    Thanks,

    Jeremy

  10. #10
    Join Date
    Jan 2004
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    Chicago
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    I haven't used Dyanamic Disk mirroring in years since Win2k. From my experience back then it was a major hassle, you had a nice low double digit performance hit from software handling the raid, and it was by no means hot swap/plug and play so you had additional downtime to swap the config over to get back up and running.

    While a good quality raid controller with Raid 1 support will cost a fair amount, just avoiding the performance hit, and having true hardware raid is well worth the initial cost.

    If you're building your own 3ware has generally always been the best out there for ATA/IDE drives.

    Or if you run SCSI nothing beats true hardware RAID, just pulling a failed drive and inserting a new one for it to be rebuilt.

    Whether you're doing backups or Raid doesn't mean you shouldn't have both. At the very least you should be doing backups, and if your budget permits have redundant drives with Raid mirroring.

  11. #11
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    Backups are a must. I'll be doing daily backups to two different offsite locations and keep the most critical data (databases) updated every two hours.

    The hardware RAID or Dynamic/Mirrored Drives is just to have a lower downtime in case of a failure. A hardware swap and OS reload can take some 3, 4 or even 5 hours so any of these solutions should prevent this. I'm trying to find reasons to either use or not use a software based mirroring solution.
    Steven Martins

  12. #12
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    Aug 2003
    Location
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    Software RAID is free and works perfectly on Fedora or Windows, you only need an additional disk. We have it running on multiple servers here and it saved some clients in the past. The only thing is that your web hosting provider will need to switch the disks if your primary disk fails. BUT, RAID protects you only from a disk failure ! If your OS is corrupted or there is a data corruption, the corruption will be reproducted on the second drive, so do not forget that you still require an external backup. There might be slowdowns if the OS needs to reconstruct the raid array or maybe under heavy disk usage but I haven't see any serious issue and I saw a LOT of software RAID installs. The advantage of software raid is that you do not depend on an additional piece of hardware, an additional hardware piece is an additional thing that can fail. Hardware RAID has other advantages like performance or hot-swap.
    Last edited by atchoooo; 06-22-2005 at 10:45 PM.
    :: Martin Leclair
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  13. #13
    Join Date
    Feb 2005
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    334
    To say software raid works perfeectly is overstating things a bit. Also to make the point, raid is not a backup. If 1 drive in a raid1 array starts corrupting itself, guess what you start mirroring?

    Your ideal solution is a decent hardware raid (not 'software' raid) plus a barebone backup/restore setup. If you arent willing to dish out what this will cost, then you will have to deal with downtime if/when murphy's law comes and kicks you in the butt. There is simply no way around this. You can possibly (and even probably) get away with a raid1 solution, but that doesnt technically answer the question you asked.

    Generally NT's built in mirroring is a 5 minute process to switch from one drive to another (boot existing mirrored drive, run repair, reboot again and you are golden), but I have had instances where an hour or so to restore from backup was faster than trying to figure out what was wrong with a second drive.

    Figure out your costs, your downtime costs, and make a decision on what you want to do.

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