Vm stun during snapshot. Typically, it happens so quickly you don't even notice.
- Vm stun during snapshot When a large snapshot is removed from a VM, depending on the size of the snapshot, there could be a long stun time at the end of the consolidation process. Is VM doing any IO intensive operation during backup time ? Yes, this is precisly the moment where the vm stun 40s, when there is an "normal" IO rate the stun are like 1s. I read you are using Veeam. Typically, it happens so quickly you don't even notice. It actually happens every time a snapshot operation is performed. Some VMs lose 3 pings. To level set, application stun goes hand-in-hand with any snapshot operation. Apr 28, 2015 · We also use the “stunned” state to create snapshots, delete snapshots, or switch over from one disk copy to another during a live storage migration aka Storage vMotion. When the snap is cleared the files are merged back into a single file and that process can cause a stun where the vm essentially pauses as it waits for the merge process to complete. The longer you wait, the bigger the snap gets. Oct 27, 2015 · I've read this excellent article by Cormac Hogan explaining why and when a Virtual Machine receives a "stun". Any active or manual snapshot on VM before backup starts ? No. From a VMware KB: A snapshot removal can stop a virtual machine for long time. Delete All is all but guaranteed to stun the VM. Usually under 1s. Not to say it can't happen, but so far I've had good experiences with VMware snapshots. Jul 16, 2019 · We have an issue where the snapshot stun is significant and can stop network access for several seconds. For Example: If the time taken to stun a VM during snapshot create with one virtual disk is X, then, multiplying with number of VMDKs sums up the total Checkpoint_Unstun required to complete Snapshot creation operation. What is the maximum stun time for the VM during vmotion operation, snapshot creation/deletion? Is there any setting to verify this? Is there anyway to reduce the stun time of the VM? Google vmware+snapshot+stun. Aug 6, 2021 · Based on documentation, it seems that the snapshot functionnality introduces : - a short virtual machine freeze state called "Stun" time, which pauses the execution of the VM at a machine instruction level for up to 1 second. log file for the VM for a Jan 19, 2010 · Each VM was in the process of removing snapshots. Answer. 0, the snapshot stun times are logged. When VEEAM backs-up the server it takes a snapshot, when the back-up is complete it removes the snapshot, this then causes the server to hang and loose connectivity for anywhere up to 1 hour, thus causing an outage to end users. I have had it stun/freeze the VM while trying to consolidate, but it has always come back when I leave it alone. Jun 9, 2016 · If you do not want to stun / pause the virtual machine you can set snapshot. This has been a huge issue for backup vendors that haven’t implemented a native storage snap solution. This happens . The process involved in the I/O is the VM-World process. Nov 9, 2023 · The affected VM protection mechanism stun is by design during the VM Snapshot creation. During backup VM freezes for more than 30 seconds. These snapshots appear to the end-user as any other Sep 21, 2022 · In both cases, the snapshot consolidation takes 12 or more minutes. During this close/delta create/attach period, the virtual machine is stunned. VMware vCenter Nov 10, 2024 · The VM stun time to complete Snapshot creation operation directly correlates with number of VMDKs associated to a Virtual Machine. In the VMware Snapshot manager,each VM had both a Veeam backup snapshot and a Consolidate Helper-0 snapshot. ESXi. This post is a follow-up explaining how you can determine the duration of a Virtual Machine stun on the most common vSphere functions: Create a Snapshot; Delete a Snapshot; vMotion; Create a snapshot VMware recently patched an issue in 6. Dec 11, 2014 · Looks like a similar issue that is described over here > Snapshot removal issues of a large VM That's a pretty large topic to read, so as a short summary - VM stun can happen during snapshot commit operation. Feb 23, 2016 · Application stunning during the snapshot process is a topic that often bubbles up in customer conversations on data protection for VMware environments. We're currently experiencing minor stuns during both snapshot creation and removal, on all VMs. As mentioned above, it's called a VM stun. On a side note, I've found that additional vmdk drives increase stun times considerably. 7u3 that was causing stun times on our MSSQL VM to randomly be over 10sec. A very intersting thread. Wait how does reverting a snapshot not stun a VM? Probably not exactly stun but the state of the VM is killed and started from the snapshot so there will be a moment in time where the VM appears to be stunned right? Mar 22, 2021 · Keepalived virtual IP (VIP) management and failover does not work when using VMware based snapshot stun is to long; Veeam backup degrades VMware datastore/array performance during VMware based snapshot May 30, 2013 · Good Morning All, Thanks for taking the time to look! I have an issue with numerous virtual servers on our server estate. Oct 4, 2012 · During the snapshot removal step of a Veeam Backup & Replication task, the source VMware VM loses connectivity temporarily. When the snapshot removal finished, all 3 VMs returned to normal operation. I work with a similar setup quite regularly. 6. More information in this KB article. maxIterations to 20 (or higher). When this happens, system time in VM also stops and resets to current time after the freeze. Get Enterprise and backup from storage snapshots. VMware vSphere. Internal memory is not included in the snapshot. log) will contain messages similar to: backups and eliminate the need to perform regular full-VM backups. This will ensure that the bind operation is held by the same ESXi host and snapshot consolidation completes without causing long pause. Nov 27, 2024 · High VM Stun time during snapshot deletion or SVmotion failure on ESXi 6. Mar 28, 2017 · It's a known issue with VMware that it performs what is called a "stun" during certain operations, such as vmotion, and snapshot create/delete. As a rule, usually anything that involves complex disks changes while the VM is running will require stunning the VM. Each virtual machine's log file (vmware. When the the snapshot is created for a virtual machine, disks are closed in order to create delta disks and attach them to virtual machine. Workaround: The PowerProtect Data Manager VMware Protection solution offers the Transparent Snapshot Data Mover (TSDM) solution, which does not require a VM snapshot to perform the backup. Jul 4, 2019 · SAP, also Orchestrator on some VM, or custom apps. Nov 22, 2019 · To resolve this issue place the virtual machine which exists in the vVOL datastore and the virtual machine which involves in the backup process on the same ESXi host. This causes an issue since we have several RDP servers and SQL servers and when the snapshot occurs it will disconnect those servers. Dec 7, 2020 · Because VMware snapshots is always a topic for backups, I want to share my latest experiences with VM-snapshots on NFS. Larger/more active machines are more likely to become stunned during snapshot removal, due to the relatively large amount of data that has to be merged back into the base disk. I had to troubleshoot a problem with system time within a VMware vSphere VM. Might help track down your issue. No heavy loads, so no long stuns - total stun periods are about 2-4 seconds per VM during backup, and the stun is not continious. 5 Update 2 hosts freeze at the *creation* of a snapshot. 5. Note: Beginning in ESXi 5. Veeam does not remove the snapshot itself, Veeam sends an API call to VMware to have the action performed. However, I've never had a snapshot deletion go wrong or cause the VM to crash unrecoverably. The snapshot size is small (sesparse file is 16GB big but du -h displays only 120MB being used), but during consolidation ESXi writes the whole time (10+ minutes) at 80-120MB/s to the storage array. ESX. IMPROVeD SnaPShOT hanDlInG In VMWaRe vVOlS Because each VM has its own virtual volumes on the array, it is possible to utilize integrations between vSphere and the array to conduct array-based snapshots on a per-VM level. Nov 4, 2019 · We’ve been using VMware and Veeam for a while now and I’ve been coming across a problem where a VM will lose connection and effectively go offline during the backup. When snapshots consolidate, they halve repeatedly until the last one where it pauses the VM stuns" it briefly. Previously, during normal snapshot removals, I have not had this issue on these 3 servers. How Long is the Unstun Time for a Virtual Machine after a Snapshot Removal? Facts. The freeze periode depends on the VM. so for near real-time application, it can inflict loss of ongoing transactions and sessions. book Article ID: 317708. calendar_today Updated On: Products. The issue is the snapshot grows as it sits and reconsolidation will "STUN" the VM. This means vSphere will do more tries (iterations) to commit the snapshot files. We’re using reverse incremental forever backups and the Veeam server is using direct SAN. In case of pending change block tracking initialization this phase of snapshot creation will result in longer stun time. This would eliminate any VM stun completely and eliminate failover events, as long as they are associated with the STUN caused by VMware snapshot removal. Backup only the passive or a read-only server within the AAG, using Native SQL backups with RBS and/or VM level backups. Mar 12, 2015 · VM's running on several ESXi 5. Some VMs even have a freeze period of 1 minute! Network connection is lost during freeze. During this stun, the guest OS is frozen, and so when it comes back, the system clock is behind. 4. I've talked to VMWare who told me to talk to our datastore vendor. The VM shows as being online in vCentre but it doesn’t show as having an IP address or that VMware tools is installed. both vMo and SVMo are impacted by how much memory or disk changes occur during the transitions. 7U2 or later. However, in some circumstances such as a VM with a large storage footprint, VMs consuming large amounts of storage IO, or storage that isn't fast enough, the VM stun can be disruptive. To determine this stun time, check the vmware. Jan 8, 2020 · Hi . nsnd ecxxwd zgdj oatfg wzeiw xgyaf ckklpf lxm jtztz xhj