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38 votes
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Is it safe to mount the same partition to multiple VMs?

In general, no, unless you meet one of two very specific constraints. Either: The device needs to be exposed read-only (this MUST be at the device level, not the filesystem level) to all the VMs, and ...
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28 votes
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Is KVM a type 1 or type 2 hypervisor?

KVM is not a clear case as it could be categorized as either one. The KVM kernel module turns Linux kernel into a type 1 bare-metal hypervisor, while the overall system could be categorized to type 2 ...
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27 votes

xvda1 is 100% full, What is it? how to fix?

I know i am replying in this thread after nearly 5 years but it might help someone, I had the same problem, i had m4.xlarge instance df -h told that the /dev/xvda1 was full, - 100% Filesystem ...
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  • 425
19 votes

Is it safe to mount the same partition to multiple VMs?

If you don’t run cluster-aware file system inside your VMs you’ll simply destroy your shred volume immediately after first metadata update. Full clarification story is here: https://forums....
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18 votes

CRITICAL STRUCTURE CORRUPTION on Windows Server 2012 R2

xenpci.sys (EJBPV XenPCI Driver (Checked Build), James Harper) (Checked Build) is a huge red flag. You absolutely should not be using "checked" builds of anything in production. If your hosting ...
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  • 55k
15 votes

Multiport Server NIC ports?

These devices are typically seen in the OS as four separate network devices and they can be used just like the four separate NICs you had before.
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  • 97k
14 votes
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Is Administering XenServer like administering CentOS?

Keep in mind that the OS is stripped even if based on a release, as if the gear is in the HCL, you will mostly never use any OS command. Most command you will ever use to administer it would be in ...
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  • 16.2k
12 votes
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Meltdown & Spectre - Does patching the guest kernel of an unpatched hypervisor prevent cross-VM memory leaks?

From what I understand of the vulnerabilities, no - the speculative caching attacks bypass all of the CPU's protections against a process grabbing memory from whatever arbitrary address. I believe ...
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10 votes

Is Administering XenServer like administering CentOS?

Primarily, you are committing to work in the XenServer way. This product is essentially an appliance and most of the things that are different between Debian and CentOS are hidden from you anyway or ...
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  • 97k
10 votes

Is KVM a type 1 or type 2 hypervisor?

If Hyper-V is type 1, then KVM is type 1 as well. There are no hardware services being emulated by the operating system in KVM. Frankly, the whole type 1 vs type 2 terminology is obsolete and ...
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7 votes

CRITICAL STRUCTURE CORRUPTION on Windows Server 2012 R2

Xen 3.4.4 is too old. 13 March 2013 Windows 2012 R2 got released on 18 October 2013. To give you an actual comparison, XenServer from Citrix added Windows Server 2012 R2's support in their version ...
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  • 16.2k
6 votes

Machine check events logged

mcelog was removed in Debian 10+ (Buster) and Ubuntu 18.04+ The functionality has been replaced by rasdaemon.
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  • 206
6 votes
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Handling /etc/fstab when upgrading linode from Xen to KVM

You have no way of predicting what the device names or IDs will be after a significant hardware change (virtual hardware in this case, from Xen to KVM). Linode is the only entity here who knows what's ...
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  • 5,562
6 votes
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How can I convert a iSCSI system disk from XenServer to another format

To get disk image do P2V and/or V2V: attach iSCSI to Windows by ISCSI initialtor. create VHDX using Disk2vhd (https://technet.microsoft.com/en-us/sysinternals/ee656415.aspx) convert VHDX to QCOW ...
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6 votes

How to combine disks from XEN-hosts into one storage?

There are some storage solutions that operate in a similar way as to VMware vSAN. The ones that got popularity in virtualization sphere are: Dell EMC Unity: I doubt they support Xen though. HPE ...
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  • 8,723
5 votes

Hammered by botnet; iptables can't keep up

You obviously can't keep up with this sort of attacker by hand. If they have that many IP addresses, this won't work. Have you analyzed what the bots are doing? Are they trying to send spam? Scraping ...
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5 votes
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Moving LVM volume group from one physical disk onto another

A volume group can have multiple physical disks (or in your case, partitions). First you need to have space on your larger disk (/dev/sda). You did not mention that in your post, but based on your ...
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  • 4,914
5 votes
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XenCenter no OS boot parameters field

The first VM is running in PVHVM mode, so QEMU is working with Xen to virtualize the hardware behind the VM. This mode is for OS that does not support Xen paravirtualization in general, like Windows ...
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5 votes
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CentOS 7 on XenServer 6.5

You need to start the installer with inst.vnc option. Select option "Install CentOS 7" and then press [tab]. Remove 'quiet' and add 'inst.vnc' to kernel command line. Press [enter]. After that, wait ...
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  • 5,147
5 votes

Multiport Server NIC ports?

As others have already mentioned, yes, a 4-port network card will be recognized and usable just like 4 separate network interfaces. However, in particular with 4-port cards, you should pay attention ...
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  • 4,103
4 votes

xvda1 is 100% full, What is it? how to fix?

I've recently run into this issue on Amazon Linux. My crontab outbound email queue /var/spool/clientmqueue was 4.5GB. I solved it by: Locating large files: sudo find / -type f -size +10M -exec ls -...
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4 votes

xvda1 is 100% full, What is it? how to fix?

I have just solved that problem by running this command: sudo apt autoremove and a lot of old packages were removed, freeing up 5 gigabytes, for instance there was many packages like this "linux-...
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  • 41
4 votes

xvda1 is 100% full, What is it? how to fix?

Paulo was on the right track for me, but when I tried to run sudo apt autoremove it responded: Reading package lists... Error! E: Write error - write (28: No space left on device) E: IO Error ...
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  • 141
4 votes

Can I virtualize multiple hosts into one virtual system?

You actually can now, although it requires InfiniBand which may be out of your price range. The only one that I know that can do this is ScaleMP (http://www.scalemp.com/) Basically it makes all the ...
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  • 141
4 votes

Use SSHFS on XenServer 6.1

Although this is an old question, I have just figured this one out myself. First.. what DOES NOT WORK (All tested on XenServer 6.5): xe-import filename=/dev/stdin does not work.. at all. It does ...
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4 votes

How to change boot device on vm installed on Citrix Xen Server to DVD

I had the same issue as B14D3 using the same version of Xenserver and VMs with Centos 6 and 7. I need to resize the file system using gparted, to accomplish that I need to boot from the live dvd. I ...
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4 votes

Ubuntu on VPS becomes unresponsive: BUG: soft lockup - CPU#0 stuck for 22s

Well I couldn't find any solution to this problem whatever I tried. In the end I replaced Ubuntu with Debian 7.0, and the problem went away, along with some anomalous CPU usage which didn't show up in ...
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4 votes

Ubuntu on VPS becomes unresponsive: BUG: soft lockup - CPU#0 stuck for 22s

Hope this helps anyone looking at this problem in the future. We've experienced this issue in a similar environment: Ubuntu 14.04 3.13.0 Kernel QEMU KVM environment Our Splunk cluster master was ...
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4 votes
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Xen: 'this operation could not be performed' (VDI is in use) error?

(For Xen 6.2) If you have access to XenCenter go to 'view' 'show hidden' and make sure that there isn't a job running for this VM already. If there is, stop and delete it. This may happen if you ...
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  • 2,297
4 votes

Remote automated provisioning to a XenServer Hypervisor

For the next guy looking into this: The solution is to read the XenServer guest installation guide and use a search engine. ;) First, there's a ansible playbook with nice documentation for setting ...
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