Converting to a virtual environment
-
@BRRABill said in Converting to a virtual environment:
@scottalanmiller said
Yeah, and while I feel that SD is the best option technically, I'm changing my recommendations for most users based on how difficult it has been to get XS to treat the SD card like it should. Hopefully at some point we will be able to produce a super simple guide for that, but for now, we cannot. Partially because I can't get access to even a desktop to work on that stuff physically which is pretty much needed for this kind of testing.
As I have been looking into this, and also backups (in the name of recovering a XS host), I"m wondering if installing to a separate drive, and just doing the backups of the host won;'t be the easiest way to recover from a failed XS host.
Again, that is basically the recommendation of XS, strangely enough from the same paragraph referenced earlier.
"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."You said right here, this may be a different topic all together. That they recommend that you restore the host by installing it from the media. That would imply that you don't backup the host itself at all.
-
@coliver said
You said right here, this may be a different topic all together. That they recommend that you restore the host by installing it from the media. That would imply that you don't backup the host itself at all.
Then the next page they say
"Citrix recommends that you frequently perform as many of the following backup procedures as possible to
recover from possible server and/or software failure."And go into the backups I mention.
This only works for the original machine, though. But I imagine that you could replicate this on a new XS (by attaching the SR and restore metadata) pretty "easily".
-
@BRRABill said in Converting to a virtual environment:
@scottalanmiller said
Their recommendations are telling you NOT to backup the host. Why jump to backing up the host? We don't backup any hypervisor (VMware ESXi, Hyper-V, KVM, etc.) It's just not practical. It's essentially stateless. What state it keeps is generally minor and handled some other way (doesn't XO or XC recreate most of that automatically?) I feel like this is a similar thought process to imaging the desktops for recovery that you used to want to do... sounds good at a high level but in practice, isn't practical. Just reinstall XS and be on your way.
No, they recommend backing up the host.
Basically, if you backup the host, and also backup the VM metadata, it's supposedly pretty easy to restore.
The host through XC and the metadata through xsconsole. (The metadata can be scheduled, even.)
(AND AND it writes to the place where the logs kept screwing up the XS. But it writes it as a VHD, of course.)
SO they you reinstall XS, restore it from backup, introduce the SR, and restore the metadata.Is the metadata on the SR?
-
-
@BRRABill said in Converting to a virtual environment:
@scottalanmiller said
Is the metadata on the SR?
Yes.
It makes a .VHD file when you do the backup.
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?
-
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?
-
@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?
But if the metadata isn't on the host, and XS says that you should not back that up, why would you want XO to have an option for that? Just rebuild from the installer (think of this as being pre-backed up) and the metadata is already available.
-
@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
- Run the command:
xe pool-dump-database file-name=<backup> - 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.* - Run the command:
-
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)
