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Citrix Announces First Cumulative Update for XenServer 7.1

By Andy Melmed On 14 września 2017 · Add Comment

Citrix has posted a blog announcing the availability of XenServer 7.1 CU1, the first cumulative update for the XenServer 7.1 Long-Term Support Release (LTSR).

CU1 rolls-up all hotfixes released on XenServer 7.1 to date. While there are no new features introduced in this update, a number of additional fixes are included to further enhance and simplify XenApp and XenDesktop environments. Information pertaining to these fixes can be found in the release notes.

Of particular significance, this cumulative update provides customers on Long-Term Support Release (LTSR) 7.1 with the latest platform fixes applicable to v7.1. Unlike Current Releases (CR), which provide access to new features on an almost quarterly basis, Long-Term Support Releases are designed for customers who, possessing the features they need to optimize their XenApp and XenDesktop environments, intend to remain on the LTSR for the foreseeable future. For these customers, using a Long-Term Support Release offers stability - Citrix will support the LTSR for up to 10 years – as well as access to fixes as they become available. You can learn more about the differences between Long-Term Support and Current Releases here.

Wondering if XenServer 7.1 Enterprise edition is right for your organization? Click here to download a free trial version.

Cheers!

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Changes to Hotfixes and Maintenance for XenServer Releases

By Tobias Kreidl On 14 września 2017 · Add Comment

XenServer (XS) is changing as a product with more aggressive release cycles as well as the recent introduction of both Current Release (CR) and Long Term Service Release (LTSR) options. Citrix recently announced changes to the way XenServer updates (hotfixes) will be regulated and this article summarizes the way these will be dealt with looking forward.

To first define a few terms and clarify some points, the CR model is intended for those who always want to install the latest and greatest versions, and these are being targeted for roughly quarterly releases. The LTSR model is primarily intended for installations that are required to run with a fixed release. These are by definition required to be under a service contract in order to gain access to periodic updates, known as Cumulative Updates or CUs. The first of these will be CU1. Since Citrix is targeting support for LTSR versions for ten years, this incurs quite a bit of cost over time and is much longer than a general CR cycle is maintained, hence the requirement for active support. The support for those running XS as part of running licensed versions of XenApp/XenDesktop will remain the same, as these CR licenses are provided as part of the XenApp/XenDesktop purchase. There will still be a free version of XenServer and the only change at this point will be that on-demand hotfixes for a given CR will no longer be available once the next CR is released. Instead, updates to quarterly releases will be needed to access and stay on top of hotfixes. More will be discussed about this later on. End-of-life timelines should help customers in planning for these changes. Licensed versions of XenServer need to fall under active Customer Success Services (CSS) contracts to be eligible for access to the corresponding types of updates and releases that fall outside of current product cycles.

At a Glance

The summary of how various XS versions are treated looking forward is presented in the following table, which provides an overview at a glance.

XenServer Version	Active Hotfix Cut-Off	Action Required
6.2 & 6.5 SP1	EOL June 2018	None. Hotfixes will continue to be available as before until EOL.
7.0	December 2017	Upgrade or buy CSS.
7.1	December 2017	Upgrade or buy CSS (to stay on the LTSR stream by deploying CU1)
7.2	At release of next CR	Upgrade to latest CR, or buy CSS to obtain 4 months more of hotfixes (and thus skip one CR)

In the future, the only way to get hotfixes for XS 7.2 without paying for a CSS will be to upgrade to the most current CR once released. Customers who do pay for CSS will also be able to access hotfixes on 7.2 for a further four months after the next CR is released. This would in principle allow you to skip a release and transition to the next one beyond it.

What Stays the Same

While changes are fairly significant for especially users of the free edition of XS, some aspects will not change. These include:

· There will still be free versions of XenSever released as part of the quarterly CR cycle.

· The free version of XS can still be updated with all released hotfixes until the next CR becomes generally available.

· XS code still remains open source.

· Any hotfixes that have already been released will remain publically available.

· There will be no change to XS 6.2 through 6.5 SP1. They are only going to get security hotfixes at this point, anyway, until being EOLed in June 2017.

In Summary

First off, stay calm and keep on maintaining XS pretty much as before except for the cut-offs on how long hotfixes will be available for non-paid-for versions. The large base of free XS users should not fear that all access to hotfixes is getting completely cut off. You will still be able to maintain your installation exactly as before, up to the point of a new CR. This will take place roughly every quarter. This is a pretty small amount of extra effort to keep up, especially given how much easier updating has become, in particular for pools. Most users would do well to keep up with current releases to benefit from improvements and to not have to apply huge numbers of hotfixes whenever installing a base version; the CR releases will include all hotfixes accumulated up to that point, which will be more convenient.

What To Do

Any customers who already have active CSS contracts will be unaffected by any of these changes. Included are servers that support actively licensed XenApp/XenDesktop instances, who by the way, get all the XS Enterprise features incorporated into the latest XS releases – for all editions of XA/XD. Customers on XS 7.0 and 7.1 LTSR who have allowed their software maintenance to lapse and have not renewed/upgraded to CCS subscriptions should seriously consider that route.

Citrix will provide additional information as these changes are put into place.

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From the Field: XenServer 7.X Pool Upgrades, Part 2: Updates and Aftermath

By Tobias Kreidl On 5 lipca 2017 · Add Comment

The XenServer upgrade process with XenServer 7 can be a bit more involved than with past upgrades, particularly if upgrading from a version prior to 7.0. In this series I’ll discuss various approaches to upgrading XS pools to 7.X and some of the issues you might encounter during the process based on my experiences in the field.

Part 1 dealt with some of the preliminary actions needed to be taken into consideration and the planning process, as well as the case for a clean installation. You can go back and review it here. Part 2 deals with the alternative, namely a true upgrade procedure, and what issues may arise during and after the procedure.

In-Place Upgrades to XS 7

An in-place upgrade to XS 7.X is a whole different beast compared to where the OS is overwritten from scratch. Mostly, it depends on whether or not you wish to retain the original partition scheme or go with the newer, larger, and more flexible disk partition layout. The bottom line is despite the added work and potential issues, you may as well go through with the update as it will make life easier later down the road.

Your choices here are to retain the current disk partitioning layout or to switch to the newer partition layout. If you want to know why the new XS disk layout changed, review the “Why was the XenServer 7 Disk Layout Changed?” section in Part 1 of this blog series.

In my experience, issues found with in-place upgrades cover five areas – I’m going to cover them as follows:

Pre-XS 7 Upgrade, Staying the Course with the Original Partition Layout
The 72% Solution
The (In)famous Dell Utility Partition
XS 7.X to XS 7.X Maintaining the Current Partition Layout
XS 6.X or7.X to XS 7.X With a Change to the New Partition Layout (plus possible issues on Dell Servers with iDRAC modules)

Pre-XS 7 Upgrade, Staying the Course with the Original Partition Layout

If you choose to stick with the original partition layout, the rest of your installation experience – whether you go with the rolling pool upgrade, or conventional upgrade – will be pretty much the same as before.

As with any such upgrade, make sure to check ahead of time that the pool is ready for this undertaking:

XenCenter has been upgraded
Assure the proper backups of VMs, metadata, etc. have been performed
That all VMs are agile or in the case of a rolling pool upgrade, at least shut down on all local SRs.
All hosts must not only be running the same version of XenServer, but must have the identical list of hotfixes applied.

Depending on the various ages of the hosts and how hotfixes were applied, you could run into the situation where there is a discrepancy. This can be particularly frustrating if an older hotfix has since been superseded and the older version is no longer available, yet shows up in the applied hotfix list. Though I’d only recommend this in dire circumstances (such as this, where the XenServer version is going to be replaced by a new one anyway) there are ways to make XenServers believe they have had the same specific patches applied by manipulating the contents of /var/update/applied directory (see, for example, this forum thread).

One thing you might run into is the following issue, covered in the next section, which incidentally appears to be independent of whichever partition layout you use.

The 72% Solution

This is not really so much of a solution, but rather a warning as to what you may encounter and what to do before you potentially run into this or what to do afterwards should you encounter it.

This issue apparently crops up frequently during the latter part of the installation process and is characterized by a long wait with a screen showing 72% completion of the installation that can last anywhere from about five minutes to over an hour in extreme cases.

One apparent cause of this is if you have an exceedingly large number of message files on your current version of XS. If you have the chance, it would be worthwhile taking the time to examine the contents of the area where these are stored and manually clean up any ancient versions within those areas under /var/lib/xcp/blobs/ in particular as most of these reside under the “messages” and “refs” subdirectories, paying attention also to the symbolic links.

If you do get stuck in the midst of a long-lasting installation you can escape out by pressing ALT+F2 to get into the shell and check the installer logs under /tmp/install-log to see if it has thrown any errors (thanks, Nekta -- @nektasingh -- for that tip!). If all looks OK, continue to wait until the process completes.

The (In)famous Dell Utility Partition

Using the rolling pool upgrade for the first time, I ran into a terrible situation in which the upgrade proceeded all the way to the very end and just as the final reboot was about to happen, I got this error popping up on the console:

Which read:

An unrecoverable error has occurred. The error was:

Failed to install bootloader: installing for i386-pc platform.

/usr/sbin/grub-install: warning: your embedding area is unusually small. core.img won’t fit in it..

/usr/sbin/grub-install: warning: Embedding is not possible. GRUB can only be installed in this setup by using blocklists. However blocklists are UNRELIABLE and their use is discouraged..

/usr/sbin/grub-install: error: will not process with blocklists.

You can imagine the reaction.

What caused this and what can you do about it? After all, this was something I’d never encountered before in any previous XS upgrades.

It turns out that the reason for this is the Dell utility partition (see, for example, this link). The Dell utility partition is a five-block partition that Dell puts on for its own purposes at the beginning of many of its servers as they ship. This did not interfere with any installs up to and including XS 6.5 SP1, hence this came to me as a total surprise when I first encountered in during a XS 7 upgrade.

And while this wasn't an issue initially or in one particular upgrade which for whatever reason managed to squeak by without any errors being reported whatsoever, it's too small to hold the initial configuration needed to do the installation under most circumstances when installing XS 7.

What's bad is that the XenServer installation doesn't apparently perform any pre-checks to see if that first partition on the disk is big enough. This is the case for both UEFI and Legacy/BIOS boots.

The solution was simply to delete that sda1 partition altogether using fdisk and re-install. Deleting the partition can be performed live on the host prior to the installation process.

You can then successfully bypass this issue. I have performed this surgical procedure on a number of hosts with success and have not experienced any adverse effects; you do not even require a vorpal sword to accomplish this task.

Possibly future upgrade processes will be better accommodating and should perform a pre-check for this along with looking at other potential inconsistencies such as the lack of VM agility or uniformity of applied hotfixes.

XS 6.X or 7.X to XS 7.X With a Change to the New Partition Layout

This is the trickiest area where most, including me, seem to encounter issues.

One point that should be clarified right away is:

Any local partition on or partly contained on the system disk to be upgraded is going to get destroyed in the process.

There are no two ways about this. Hence, plan ahead: either

Storage Xenmotion any local VMs to pooled storage, or
Export them.

If you want or need to preserve your existing local storage SRs, you’ll have to stay with the original partition scheme.

Should you decide to update the new partition scheme, before the upgrade, you will need to perform the following action:

# touch /var/preserve/safe2upgrade

The upgrade process (to preserve the pool) will need to be performed using the rolling pool upgrade. The caveat is that if anything goes wrong during any part of the upgrade process, you will have to exit and try to start over. The end point can vary from it being simple to reconvene from where you left off, to having things in a broken state, depending on the circumstances.The pre-checks performed are supposed to catch issues beforehand and allow you to take care of them before launching into the upgrade process, but these do not always trap everything! Above all, make sure that:

All VMs are agile, i.e. that there are no VMs running or even resident on any local storage
High Availability (HA) and Workload Balancing (WLB) are disabled
You have created metadata backups to at least one pooled storage device or exported it to an external location
You have plenty of space to hold VMs on whatever hosts remain in your pool, figuring you’ll have one out at any given point and that initially, only the master will be potentially able to take on VMs from whichever hosts is in the process of being upgraded

Preferably also have recent backups of all your VMs. It’s generally also a good idea to keep good notes about your various host configurations, including all physical and virtual networks, VLANs, iSCSI and NFS connection and the like. I’d recommend doing an “export resource data” for the pool, which has been available as a utility since XS 6.5 and can run from XenCenter.To export resource data:

In the XenCenter Navigation pane, click Infrastructure and then click on the pool.
From the XenCenter menu, click Pool and then select Export Resource Data.
Browse to a location where you would like to save report and then click Save.

You can chose between an XLS or CVS output. Note that this feature is only available on XenCenter with paid-for licensed version of XenServer. However, it can also be run via the CLI for any (including free) version of XS 6.5 or newer using:

# xe pool-dump-database file-name=target-output-file-name

Being prepared now for the upgrade, you may still run into issues along the way, in particular if you run out of space to move VMs to a different server or if the upgrade process hangs. If the master server manages to make it through the upgrade and the upgrade process fails at some point later, one of the first consequences will be that you will no longer be able to add any external hosts to the pool because the pool will be in a mixed state of hosts running different XS versions. This is not a good situation and makes it very difficult under some circumstances to recover from.

Recommended Process for Changing XenServer Partition Layout

Through various discussions on the XenServer discussion forum as well as some of my own experimentation, this is what I recommend as the most solid and reliable way of doing an upgrade to XS 7.X with the new partition layout coming from a version that still has the old layout. It will take quite a bit longer, but is more reliable.

In addition to all the preparatory steps listed above:

You will be needing to eject all hosts from the pool at one point or another, so make sure you have carefully recorded the various network and other settings, in particular some which are not retained as such in the metadata exports, such as the individual iSCSI network connections or NFS connections.
Copy your /etc/fstab file and also be sure to check for any other customizations you may have done, such as cron jobs or additions to /etc/rc.local (and also note that rc.local does not run on its own under XS 7.X, so you will need to manually enable it to do so – see the section “Enabling rc.local to Run On Its Own” below).

Once your enhanced preparation is complete:

Start with your pool master and do a rolling pool upgrade to it. Do not attempt to upgrade to the new partition layout! After it reboots, it should still have retained the role of pool master. Note that the rolling pool upgrade will not allow you to pick which host it will upgrade next beyond the master so be certain that any of these hosts can have all its VMs fit on the pool master. If necessary move some or all the VMs on the pool master onto other hosts within the pool before you commence the upgrade procedure.
Pick another host and migrate all its VMs to the pool master.
Follow this procedure for all hosts until the pool is completely upgraded to the identical version of XS 7.X on all pool members. You can either continue to use the rolling pool upgrade or if desired, switch to manual upgrade mode.
Making sure you’ve carefully recorded all important storage and network information on that host, migrate all VMs off a non-master host and eject it from the pool.
Touch the file /var/preserve/safe2upgrade and plan on the local SR being wiped and re-created. Then shutdown the host and perform a standalone installation to that just ejected host. It will have the new partition layout.
Reduce the network settings on this host to just a single primary management interface NIC, one that matches the same one it had initially. Rejoin this just upgraded host back into the pool. Many of the pool metadata settings should automatically get recreated, in particular any of the pooled resources. Update any host-specific network settings as well as other customizations.
Continue this process for the remainder of the non-master hosts.
When these have all been completed, designate a new pool master using the command “xe pool-designate-new-master host-uuid=new-master-uuid”. Make sure the transition to the new pool master is properly completed.
Eject what was the original pool master and perform the standalone upgrade and rejoin the host to the pool as before.
Celebrate your hard work!

While this process will take easily two times as long as a standard upgrade, at least you know that things should not break so badly that you may have to spend hours of additional time making things right. As a side benefit (if you want to consider it as such), it will also force you to take stock of how your pool is configured and require you to take careful inventory, In the event of a disaster, you will be grateful to have gone through this process as it may be very close to what you may have to go through under less controlled circumstances!I have done this myself several of times and had it work correctly each time.

An Additional Item: If the Console Shows No Network Configured on Dell Servers with iDRAC modules

This condition can show up unexpectedly and while normally something like this can be handled if the host is found to be in emergency mode with an “xe pool-recover-slaves” command, that’s not always the case. And even more oddly, if instead you ssh in and run xsconsole from the CLI, all looks perfectly normal, including all the network settings that appear present and correct and also match the settings visible in XenCenter. This condition, as far as I know, seems unique to Dell servers and was seen with iDRAC 7, 8 and 9 modules. Here's what it looks like:

The issue here appears to have been a change in behavior that kicked in starting with XenServer 7.1 and hence may not even be evident in XS 7.0.

The fix turned out to be an upgrade all the BIOS/firmware and iDRAC configurations. In this particular case, I made use of the method I described in this blog entry and that took care of it. Note that this still does not seem to consistently address this issue, in particular with some older hardware (e.g., R715 with an iDRAC 6, even after updating to DSU 1.4.2, BIOS 3.2.1, but being stuck at iDRAC version 1.97 – apparently not upgradeable).

Enabling rc.local To Run On Its Own

The rc.local file is not automatically executed by default under RHEL/CentOS 7 installations, and since XS 7 is based on CentOS 7, it is no exception. If you wish to customize your environment and assure this file is executed at boot time, you will have to manually enable /etc/rc.local to run automatically on reboot on XenServer 7.X and to do so, will need to run these two commands:

# chmod u+x /etc/rc.d/rc.local
# systemctl start rc-local

You can verify that rc.local is now running with the following command, which in turn should produce output similar to what is shown below:

# systemctl status rc-local

   rc-local.service - /etc/rc.d/rc.local Compatibility
   Loaded: loaded (/usr/lib/systemd/system/rc-local.service; static; vendor preset: disabled)
   Active: active (exited) since Sun 2017-06-18 09:09:50 MST; 1 weeks 6 days ago
   Process: 4649 ExecStart=/etc/rc.d/rc.local start (code=exited, status=0/SUCCESS)

A Final Word

Once again, I will reiterate that feedback is always appreciated and the XenServer forum is one good option. Errors, on the other hand, should be reported to the XenServer bugs site with as much information as possible to help the engineers understand and reproduce the issues.

I sincerely hope some of the information in this series will have been useful to some degree.

I would like to most gratefully acknowledge Andrew Wood, fellow Citrix Technology Professional, for the review of and constructive additions to this blog.

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From the Field: XenServer 7.X Pool Upgrades, Part 1: Background Information and Clean Install

By Tobias Kreidl On 4 lipca 2017 · Add Comment

The XenServer upgrade process with XenServer 7.0 can be a bit more involved than with past upgrades, particularly if upgrading from a version prior to 7.0. In this series I’ll discuss various approaches to upgrading XenServer (XS) pools to 7.X and some of the issues you might encounter during the process based on my experiences in the field.

Part 1 deals with some of the preliminary actions that need to be taken into consideration and the planning process, as well as the case for a clean installation. Part 2 deals with the alternative, namely a true in-place upgrade procedure, and what issues may arise during and after the procedure.

Why Upgrade to XenServer 7?

XenServer (XS) 7 has been out for a little over a year now and is currently up to release 7.2. A number of improvements in scaling, functionality and features are available in XS 7, which should encourage users to upgrade to take advantage of them.

First Step in Any XS Upgrade

The first step in any XenServer upgrade is to upgrade your XenCenter to at least the minimum version required to support the newest installation of XenServer you are or will be accessing.

This step is crucial. Failure to do this causes puppies to die. This is because older versions of XenCenter won’t connect to newer versions of XS and in many cases, new features are built into the newer versions of XenCenter that are not available in older versions and support important components in the newer XS releases, including hotfix and rolling pool upgrade options, changes in licensing, and others such as supported pooled storage options. In short, your upgrade process will rapidly come to a screeching halt and there may be potential damage done unless you are working with the proper version of XenCenter.

It is also highly recommended to make backups of anything and everything prior to upgrading. More on that will be discussed later.

Summary of Pre-Upgrade Checks

From experience, the following are key activities to perform before upgrading any XenServer pool:

XenCenter has been upgraded to at least the version that does or will match your newest pool

Assure the proper backups of virtual machines (VMs), metadata, etc. have been performed
Make sure that all VMs are agile (can be migrated to other hosts within the pool) or in the case of a rolling pool upgrade, at least shut down on all local SRs
All hosts must not only be running the same version of XenServer, but must have the identical list of hotfixes applied
Clean up old messages in /var/lib/xcp/blobs/

I’d also recommend doing an “export resource data” for the pool, which has been available as a utility since XS 6.5 and can run from XenCenter.

To export resource data:

In the XenCenter Navigation pane, click Infrastructure and then click on the pool.
From the XenCenter menu, click Pool and then select Export Resource Data.
Browse to a location where you would like to save the report and then click Save.

You can chose between an XLS or CVS output. Note that this feature is only available on XenCenter with paid-for licensed versions of XenServer. However, it can also be run via the CLI for any (including free) version of XS 6.5 or newer using:

# xe pool-dump-database file-name=

Benefits of a XenServer 7 Upgrade

XenServer 7 is a significant jump from XS 6.5 SP1 in many ways, including improvements in scale and performance. It also has added a number of very nice new features (see what's new in XS 7; what's new in XS 7.1; XS 7.2 ).

While any upgrade can be a bit intimidating, ones that jump to a whole new edition can be more complicated and given the changes involved here, this case was no exception. I would also recommend trying to verify your hardware is present on the HCL though it’s often slow to get populated. If in doubt and you have the extra resources, take as close as possible a spare server and try to do an installation on it first to make sure it’s compatible. If you don’t have such a machine and have the spare capacity, eject one of the hosts from your pool and use it to test out the upgrade. Before performing an upgrade on a production server or pool, it is always recommended to try this out first on a test configuration.

I do not recommend at this time the rolling pool or standalone upgrade that involves switching at the same time from the old to the new partition layout. Overall experiences within the user community have not been consistently positive.

It is hoped that the preparatory steps that are recommended before undertaking an upgrade do not prove to be too daunting. This series is intended to help with those preparations as well as give guidelines and tips how to go about the process and what to do if issues arise. There are clearly a number of ways to tackle upgrades and there are undoubtedly numerous other possible approaches. One might, for example, storage XenMotion VMs to other pools or make use of temporary pooled storage as part of the process. The detaching and attaching pooled storage to servers already running a newer version of XenServer is another possible route to explore.

Experimentation is always something that should be encouraged, albeit not on production systems!

Feedback is always appreciated and the XenServer forum https://discussions.citrix.com/forum/101-xenserver/ is one good option. Errors, on the other hand, should be reported to the XenServer bugs site with preferably sufficient detail to allow the engineers to be able to understand and reproduce the issues.

XS 7.X Leveraging a Clean Installation as an Upgrade Component

A clean install can become part of an upgrade procedure if for example an upgraded pool already exists and individual hosts or hosts from a whole different pool are to be merged into a pool running a newer version of XenServer. Hence talking about this option is relevant to upgrading. You can potentially storage Xenmotion VMs over to a new pool, then eject and dissolve individual pool members, perform a clean installation on them, and join the hosts to the new pool. Of course the target pool must have adequate resources to hold and run the VMs being moved over until the new hosts can be configured and added. This process might involve leveraging temporary external storage, for example, by creating an NFS SR.

The easiest installation scenario is a clean install, which has thankfully always been the case and this approach may work well in some instances. This is obviously suited best for a standalone server or as mentioned above, creating a server that will be joined to an existing pool.

Regardless of which upgrade process you undertake, be sure to review your VMs afterwards to see if XenTools need to be updated.

A Few Words About the XenServer 7 New Disk Layout

The main item to be aware of is that a clean installation will always create the new GPT partition layout as follows:

Size	Purpose
4GB	log partition (syslogd and other logs)
18GB	backup partition for dom0 (for upgrades)
18GB	XenServer host control domain (dom0) partition
0.5GB	UEFI boot partition
1GB	swap partition

This adds up to 41.5 GB. There can be a sixth partition which is optionally used for creating a local storage repository (SR) or a portion of a local SR if spanning it to other storage devices. See also James Bulpin's XS 7 blog for more details about the XS 7 architecture.

Here is what a real-life partition table looks like after performing an installation. Note that the space for a local SR ends up in partition 3 (in this case, a default LVM partition 94.6 GB in size):

# fdisk -l /dev/sda

WARNING: fdisk GPT support is currently new, and therefore in an experimental phase. Use at your own discretion.

Disk /dev/sda: 146.2 GB, 146163105792 bytes, 285474816 sectors

Units = sectors of 1 * 512 = 512 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk label type: gpt

# Start End Size Type Name

1 46139392 83888127 18G Microsoft basic

2 8390656 46139391 18G Microsoft basic

3 87033856 285474782 94.6G Linux LVM

4 83888128 84936703 512M BIOS boot parti

5 2048 8390655 4G Microsoft basic

6 84936704 87033855 1G Linux swap

Why was the XenServer 7 Disk Layout Changed?

The XS 6.5 SP1 and earlier partition scheme was much smaller and simpler:

4 GB XenServer host control domain (dom0) partition

4 GB backup partition for dom0 (for upgrades)

The rest of the space was again available for use as a local SR in a third partition.

The default partition layout was changed under XS 7 for a number of reasons. For one, most storage devices these days start with a capacity of few hundred GB and so it makes sense to be able to allocate more space for the XenServer installation itself beyond just 8 GB. In that regard, running out of space has been a common problem caused by either a lot of hotfixes being stored or the accumulation of a lot of log files. Isolating /var/log to its own partition now helps keep XS from crashing in case it fills up. Before, /var/log was just another subdirectory on the system “/” partition and inevitably resulted in a system crash when the partition became 100% full. A separate UEFI boot area was also added. Plus, the Linux swap space was assigned to its own partition. In short, there was no reason not to make use of more space and provide an improved partitioning scheme that would also scale better for larger pools containing a lot of VMs.

Note: One idiosyncrasy of XS 6.5 SP1 is that it switched to a GUID partition table in order to use more than 2 TB of local storage if available, but this has evidently been undone in 7.0 since GPT is no longer limited as such when running a 64-bit OS based on CentOS 7.

Note: There are changes in the minimum host physical system requirements, including a recommended minimum of 46 GB of disk space. This will impact environments that used smaller partitions or SSDs for the XS OS.

Stage Complete: Level Up!

Well done – you’ve completed Part 1. In Part 2, I’ll deal with the alternative to leveraging a clean install -- a true in-place upgrade procedure, and what issues may arise during and after the procedure.

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Citrix Announces First Cumulative Update for XenServer 7.1

Changes to Hotfixes and Maintenance for XenServer Releases

From the Field: XenServer 7.X Pool Upgrades, Part 2: Updates and Aftermath

From the Field: XenServer 7.X Pool Upgrades, Part 1: Background Information and Clean Install

Test blog

Notification test

XenServer 7.2 now available!

Creating backups with XenServer

XenCenter 7.1 update now available!

Introducing… XenServer 7.1!

AnyThin’

Citrix XenServer 7.2