Converting to a virtual environment



  • @scottalanmiller said

    That's what I thought. So if the metadata is being backed up with the VMs in place, what would you be restoring for the host?

    The host is backed up to your local machine through XC.



  • @BRRABill said in Converting to a virtual environment:

    @scottalanmiller said

    That's what I thought. So if the metadata is being backed up with the VMs in place, what would you be restoring for the host?

    The host is backed up to your local machine through XC.

    Is there a benefit to that?



  • @scottalanmiller said in Converting to a virtual environment:

    @BRRABill said in Converting to a virtual environment:

    @scottalanmiller said

    That's what I thought. So if the metadata is being backed up with the VMs in place, what would you be restoring for the host?

    The host is backed up to your local machine through XC.

    Is there a benefit to that?

    That's a good question.

    It is basically host configuration, I guess.

    If you had a lot of settings changed (such as if there were a lot of pool members, etc.) maybe it is valuable.

    This is a good article I have been working off of:
    http://techblog.danielpellarini.com/sysadmin/steps-to-take-to-restore-xenserver-from-backup/

    But I am assuming since Citrix says to take regular backups of the host, perhaps it is needed. But perhaps not.

    This is one of those times it would be great to have someone from there on here to say ... yeah, definitely or no you're crazy!



  • @Danp said in Converting to a virtual environment:

    This is one area where I feel that XO is missing an option to backup the host / metadata to a separate location. If you need to rebuild the XO host (on SD) without restoring all the VMs (local storage), how does one accomplish this if you haven't backed up the above info?

    It can be done. There is apparently a "try my best" type option.

    But it would be best to have this info, without question.

    Why it's not INCLUDED somewhere, don't ask me. Like a small config file in the SR that does mapping.

    But since you can automate the backing up of the metadata, perhaps they feel like the functionality is already there.



  • @BRRABill said in Converting to a virtual environment:

    But I am assuming since Citrix says to take regular backups of the host, perhaps it is needed. But perhaps not.

    I thought that they said not to take them.



  • @scottalanmiller See our prior discussion here.



  • @scottalanmiller said in Converting to a virtual environment:

    @BRRABill said in Converting to a virtual environment:

    But I am assuming since Citrix says to take regular backups of the host, perhaps it is needed. But perhaps not.

    I thought that they said not to take them.

    No they said to reinstall, but then proceed to say to take very regular backups of the host.

    Here's the whole thing. (NOTE: this can be done with using the CLI as well._

    *Citrix recommends that, whenever possible, you leave the installed state of XenServer hosts unaltered. That is,
    do not install any additional packages or start additional services on XenServer hosts, and treat them as if they
    are appliances. The best way to restore, then, is to reinstall XenServer host software from the installation media.
    If you have multiple XenServer hosts, the best approach is to configure a TFTP server and appropriate answerfiles
    for this purpose (see the XenServer Installation Guide).
    For VMs, the best approach is to install backup agents on them, just as if they were standard physical servers.
    For Windows VMs, as of this release we have tested CA BrightStor ARCserve Backup, and Symantec NetBackup
    and Backup Exec.
    For more information about backup tools tested, best practices, and backups in general, see the Citrix Knowledge
    Base.
    107
    Citrix recommends that you frequently perform as many of the following backup procedures as possible to
    recover from possible server and/or software failure.

    To backup pool metadata

    1. Run the command:
      xe pool-dump-database file-name=<backup>
    2. Run the command:
      xe pool-restore-database file-name=<backup> dry-run=true
      This command checks that the target machine has an appropriate number of appropriately named NICs,
      which is required for the backup to succeed.

    To backup host configuration and software
    • Run the command:
    xe host-backup host=<host> file-name=<hostbackup>
    Note:
    • Do not create the backup in the control domain.
    • This procedure may create a large backup file.
    • To complete a restore you have to reboot to the original install CD.
    • This data can only be restored to the original machine.*



  • This post is deleted!


  • wow .... errr... have I opened-up a can of worms here ?



  • @PRPL said in Converting to a virtual environment:

    wow .... errr... have I opened-up a can of worms here ?

    Yeah maybe this is a time for a fork!



  • @PRPL said in Converting to a virtual environment:

    wow .... errr... have I opened-up a can of worms here ?

    And also backed up the statement of @JaredBusch 🙂



  • Further on there is this. Perhaps this answers your question, @scottalanmiller

    "Because the privileged control domain is best left as installed, without customizing it with
    other packages, Citrix recommends that you set up a network boot environment to cleanly
    perform a fresh installation from the XenServer media as a recovery strategy. In many cases
    you will not need to backup the control domain at all, but just save the pool metadata (see
    Section 8.9.1, “Backing up Virtual Machine metadata”). This backup method should always
    be considered complementary to backing up the pool metadata."

    I take this as, if you leave it "as installed" there is no need to backup the host.



  • @scottalanmiller said in Converting to a virtual environment:

    @PRPL said in Converting to a virtual environment:

    I did look @ the free Starwind Virtual SAN, but from what I read, I understand that the free version will allow only storage and not compute, on the same host... That's allowed, only in the paid version... ??

    I've never heard of that limitation. that would be a new and surprising one. I'm quite confident that you can put your storage on your compute nodes.

    Checking with @KOOLER @StarWind_Software

    I'm making this statement, based on my understanding of the Free vs Paid document, found on https://www.starwindsoftware.com/whitepapers/free-vs-paid.pdf

    Please look @ the comparison on the second-last page of this PDF... It says, next to Deployment Scenarios , that Hyperconvergence, is available only for Certain User Statuses (Check Status)



  • @BRRABill said in Converting to a virtual environment:

    @PRPL said in Converting to a virtual environment:

    wow .... errr... have I opened-up a can of worms here ?

    And also backed up the statement of @JaredBusch 🙂

    Or mine... are you carrying Windows complexities into the simple XenServer world?



  • @PRPL said in Converting to a virtual environment:

    @scottalanmiller said in Converting to a virtual environment:

    @PRPL said in Converting to a virtual environment:

    I did look @ the free Starwind Virtual SAN, but from what I read, I understand that the free version will allow only storage and not compute, on the same host... That's allowed, only in the paid version... ??

    I've never heard of that limitation. that would be a new and surprising one. I'm quite confident that you can put your storage on your compute nodes.

    Checking with @KOOLER @StarWind_Software

    I'm making this statement, based on my understanding of the Free vs Paid document, found on https://www.starwindsoftware.com/whitepapers/free-vs-paid.pdf

    Please look @ the comparison on the second-last page of this PDF... It says, next to Deployment Scenarios , that Hyperconvergence, is available only for Certain User Statuses (Check Status)

    that does appear to say that, but goes against hundreds of posts from the company so I think that this might be outdated.



  • @BRRABill said in Converting to a virtual environment:

    Further on there is this. Perhaps this answers your question, @scottalanmiller

    "Because the privileged control domain is best left as installed, without customizing it with
    other packages, Citrix recommends that you set up a network boot environment to cleanly
    perform a fresh installation from the XenServer media as a recovery strategy. In many cases
    you will not need to backup the control domain at all, but just save the pool metadata (see
    Section 8.9.1, “Backing up Virtual Machine metadata”). This backup method should always
    be considered complementary to backing up the pool metadata."

    I take this as, if you leave it "as installed" there is no need to backup the host.

    AND that you should leave it "as installed".



  • @scottalanmiller said

    Or mine... are you carrying Windows complexities into the simple XenServer world?

    His statement being...
    "some of the biggesest threads on XS on this forum to see how unstable it is for people that do not fully know what they are doing"



  • @BRRABill said in Converting to a virtual environment:

    @scottalanmiller said

    Or mine... are you carrying Windows complexities into the simple XenServer world?

    His statement being...
    "some of the biggesest threads on XS on this forum to see how unstable it is for people that do not fully know what they are doing"

    And my sentiment being that it was only people doing non-standard things and those following the instructions and keeping it simple (with the exception of needing to skip the SD piece) it's rock solid. Is anyone having issues with normal usage? I'm not aware of a stability concern. And also I pointed out that the things that cause the "instabilities" as they are seen will do the same things on Hyper-V... so the issue isn't about XenServer, it's about people pushing boundaries on test boxes to see what breaks and where.



  • @scottalanmiller said

    And my sentiment being that it was only people doing non-standard things and those following the instructions and keeping it simple (with the exception of needing to skip the SD piece) it's rock solid. Is anyone having issues with normal usage? I'm not aware of a stability concern. And also I pointed out that the things that cause the "instabilities" as they are seen will do the same things on Hyper-V... so the issue isn't about XenServer, it's about people pushing boundaries on test boxes to see what breaks and where.

    I ain't touchin' nothing' no mores.

    (Though I am going to keep testing my /var/log theories.)



  • @scottalanmiller said in Converting to a virtual environment:

    At 90 minutes, a good backup system can almost always restore your VMs in that window. It require the backup system to be able to push a restore that quickly AND your servers to be able to ingest a restore that quickly. So a lot of ifs, but it can be done and might be the cheapest path to your goal. You still use virtualization to make the "magic" happen on this, but using the storage of the two nodes to handle this is only one option, using the backup system to get rapid backups and rapid restores is a very viable approach when you don't need to recover "in seconds."

    So, you're saying that one can backup all VMs(Data n all), onto an external media, and when the Primary host goes down, the VMs can be restored onto the secondary host ...

    Our current backup scenario is rather straight-forward... We use a backup Software (called Easus) to perform daily incremental backups (at EOD), with 1 weekly full-backup. This has worked well for us (Tried n Tested)

    So, going by what you're suggesting, can we incrementally (Every 30 mins) backup the VMs to the same USB drive, but this time, using a VM specific backup solutions such as Veeam Free...

    Also, with something like Veeam Free, does the backup source host & restore target host have to be the same ? While restoring, can I just select another host as the restore target, and boom, it'd be up n running ?

    Also, how long would be take to restore a 1TB VM ?



  • @BRRABill said in Converting to a virtual environment:

    @scottalanmiller said

    And my sentiment being that it was only people doing non-standard things and those following the instructions and keeping it simple (with the exception of needing to skip the SD piece) it's rock solid. Is anyone having issues with normal usage? I'm not aware of a stability concern. And also I pointed out that the things that cause the "instabilities" as they are seen will do the same things on Hyper-V... so the issue isn't about XenServer, it's about people pushing boundaries on test boxes to see what breaks and where.

    I ain't touchin' nothing' no mores.

    (Though I am going to keep testing my /var/log theories.)

    It's good for testing. Just don't compare issues when you are trying to break things with stability issues. Or if you do, test them equally across platforms. I know of no one testing Hyper-V in a similar fashion.



  • @PRPL said in Converting to a virtual environment:

    So, you're saying that one can backup all VMs(Data n all), onto an external media, and when the Primary host goes down, the VMs can be restored onto the secondary host ...

    Yes, that's the idea. If the backup server, network and host node are fast enough, you can restore in 90 minutes (or less.)



  • @PRPL said in Converting to a virtual environment:

    Also, with something like Veeam Free, does the backup source host & restore target host have to be the same ? While restoring, can I just select another host as the restore target, and boom, it'd be up n running ?

    No, does not need to be the same. Although Veeam Free will leave you without some of the things that you want. Unitrends or XenOrchestra will likely do a better job for you here when trying to do this for free.



  • @PRPL said in Converting to a virtual environment:

    Also, how long would be take to restore a 1TB VM ?

    Depends on a lot of things. This is an actual 1TB of data on the VM, not the size before compression?

    Let's start with the network bottleneck.. If your network for backups (and restores) is 100% dedicated, the pretty much the fastest possible 1TB restore will be two and a half hours on a GigE interface.

    On USB 3 this could be cut down to 47 minutes.

    On 10GigE it might be as low as 15 minutes.

    On 40GigE, Infiniband or whatever, in theory, it could be even faster. But that is only the network portion and assumes 100% efficiency with 100% available capacity.



  • @scottalanmiller said

    No, does not need to be the same. Although Veeam Free will leave you without some of the things that you want. Unitrends or XenOrchestra will likely do a better job for you here when trying to do this for free.

    Though no file level.

    Always better to have an agent if you need that.



  • @PRPL said in Converting to a virtual environment:

    Also, how long would be take to restore a 1TB VM ?

    The REAL questions will be far less about your network but more about your backup media, your restore media (server storage) and backup utilities. How fast do each of them work. Putting in a 10GigE network is easy and relatively cheap if you don't need much switching (or any switching.) But getting disks that can maintain the data needed to send out a restore, and then having the disks on your server to ingest a restore of 1TB is where it gets complicated. Just because your network can get it there doesn't mean that the disks, the protocol or the software doing the transfer will be able to maintain it.

    I don't know anything that will attach via USB that will be able to pull this off. You will need a more serious storage device to be able to handle it.



  • @BRRABill said in Converting to a virtual environment:

    @scottalanmiller said

    No, does not need to be the same. Although Veeam Free will leave you without some of the things that you want. Unitrends or XenOrchestra will likely do a better job for you here when trying to do this for free.

    Though no file level.

    Always better to have an agent if you need that.

    Unitrends does file level. But not for free.



  • I wonder if that import/export bug is XS would affect restoring/importing a VM...

    I'm not sure what mechanism XO uses for that on a straight restore.



  • Of major consideration in a restore like this is the write speed of the server array. RAID 10 is the fastest array type, for example, and still its write speed is half that of its read speed. So the array would have to be able to stream out 1TB in 45 minutes to be able to restore one in 90 minutes. And that's best case scenario.



  • SSDs will help, but even SSDs won't do 1TB in 90 minutes without some thoughtful design and planning.


Log in to reply