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How reliable is iSCSI storage as alternative for external USB storage for VAIL Server Backup RRS feed

  • General discussion

  • I have followed many discussions about all the pros and contras of the new DE used in Vail and understand that it’s not easy to setup an (under all circumstances) reliable (internal or external)data storage. But besides that I also will have the possibility to store my server backups on another location then just in the server itself. MS mentioned to use for external storage an external USB HD. Limited by the max USB-cable lengths, ao I prefer to use an external network drive.

    To do that I have here removed all the dust from my old  Synology DS207+ NAS, upgraded to the last firmware and put in two 2 TB greenpoints. Unfortunately I found that Vail wasn’t able  to display my network drive in the Hard Drive tab in the Dashboard.

    After a while I found that MS has implemented an iSCSI initiator in Vail and after configuring iSCSI in the NAS and Vail I was able to use my external storage for Server Backup.

    My questions:

    1.- Is it correct to use iSCSI as an alternative for external storage.

     2.- How reliable is this solution, for now on all the backups made to the NAS are reported as Successful, but is it after an (disk)crash possible  to use these backups for repairing Vail.

    3.- What is the best way to test my external backups (shared folders, client pc’s, etc.)

    Wednesday, November 3, 2010 10:27 AM

All replies

  • It's possible to use iSCSI for backups, and you'll probably be able to restore partitions other than the system partition, but I doubt you'll be able to use anything but a directly attached drive for a bare metal restore. You'd probably have to try it and see.

    As for testing backups, Vail uses Windows Server 2008 "Server Backup", so mount the backups to see if you can read them.


    I'm not on the WHS team, I just post a lot. :)
    Wednesday, November 3, 2010 12:22 PM
    Moderator
  • Hallo Ken,

    Thanks for the reply. I have already tested the backup and could restore all my share data, everything seems to work fine. I have also tried to restore small parts of the system volume, but then I got some errors … I must go in deeper to find that out.

    What I really like to know is how robust (safe?) is my iSCSI storage, what are my single sources of error. Can I still use my iSCSI storage data to restore everything after reinstalling Vail on the same or maybe on another machine. What about silent errors in my external DE-volume, can I lose all my data…?? or is it much safer to use internal storage for Server Backup?

    I know MS is putting in a lot of knowledge an work to make DE reliable but there are more (weak) links in the total chain and an robust  long-term data storage with low risks of data loss is what most of us want to have…

    Hans

    Thursday, November 4, 2010 7:32 PM
  • I can't tell you how safe your iSCSI storage is; I don't use iSCSI. For backups, though, you really want to take your backup off-site. iSCSI won't facilitate that; it will tend to discourage you from doing so.

    edit: and I also can't give an opinion on the safety of your iSCSI storage because I don't have your network and your devices. The real question is "How much do you trust your own hardware?" Personally, I take backups off-site regularly, and as I said iSCSI is pretty useless for that. Plus it's a great way to saturate your home network if you do a lot of heavy duty file manipulation.


    I'm not on the WHS team, I just post a lot. :)

    Friday, November 5, 2010 1:09 AM
    Moderator
  • I use iSCSI for my backups from Vail and Aurora. Whilst iSCSI happens to use the same ethernet connections and cables as your normal network, it does not necessarily have any impact on your network. I connect my iSCSI device using CAT 6 to a second ethernet connection on my motherboard. Thus all transput is done across the dedicated wire and it leaves my switch and network alone.

    My DroboPro has a number of means of connection as well as iSCSI, and I can at any time pick up the unit and attach it to the same server via USB or to another server offsite.

    iSCSI is just a different method of connection and does not change the way that data is stored on the disc. Thus it is like saying that USB is not safer than Firewire.

    iSCSI needs the correct initiators (that happily are built into Windows 7). Thus they cannot be used over iSCSI to do a bare metal restore, but all the data is safe for when you have rebuilt the server.

    Some devices do data scrubbing when the drive is not otherwise occupied. This involves reading and re-writing data to avoid silent failure or bit rot. Both my DroboPro and network attached DroboPro-FS do this but not my version 2 Drobo so check that your unit does.

    My view is that if your data is worth backing up, then it is worth doing it properly and protect it against many risks. Thus I have at least three copies of all my data that I care about. Each DroboPro has 16TB and each has protection against 2 disc failures. One is kept offsite.

    Vail is in beta. I had a system corruption three weeks ago and I lost several vail services and a repair would not run. I did a clean install and then I had a bunch of security errors with my old files and shares. I could have sorted it all out but it was easier to check that my two other copies were fine and then just wiped all system and data discs. Bad things do happen. And they can happen at the worst possible time. Even if your off site backup is all that you are left with and it is a month out of date, it is a world better than none at all.

     

    Ian

    Friday, November 5, 2010 6:35 PM
  • Ian,

    Thanks, Yes you are correct ... you need more than one copy of your important data. That’s why I am trying to setup an "robust  long-term data storage with low risks of data loss" in the first time.

    I understand that this subject goes much wider then this Vail forum, but the deeper I go into this the more I see how difficult  “long-term data storage” really is...

    Hans

     

    Monday, November 8, 2010 5:01 PM