Posts made by rfx77

@zmk We only had the dmesg entris on Xen, not on VMWare and not on HyperV

@arc1 same situation here. we also had dmesg entries when doing live-migration. but the vm did not have any issues beside that.

@flakpyro

Our Issue with commvault was that despite it mounts the snapshots in the proxy VM it has to read them as a whole. So Inc Backups take nearly as long as Full backups. When you want to backup 20TB+ Incs every night, Thats not acceptable. So the Lack of CBT is really a big deal when doing VM Backups.

Performance with CommVault would be not that big of a problem since you can do multiple streams and multiple VMs simultanously but we could not get past 600MB/s which is a Xen Problem as of our Testing. With HyperV we see Performance in access of 1.6GB/s in the same Scenarios. But also this performance would be much to slow to do Incs every night.

We tested XO CBT but it was not stable and for what i read in the posts there seems to be problems with CBT and Live-Migration so that the CBT state seems to be lost. Also a big Problem for us.

When we used CommVault to backup multiple VMs we ran into Blue-Screens of the Xen Toolstack in the Windows VMs when attaching or detaching Snapshot-VDIs to the Proxy VMs. There clearly is a bug in the Xen Windows Drivers. So we had to reduce concurrency which reduced backup speed.

We didn't do a short test with xen, we migrated out internal production Cluster to it from VMWare and used it for about 4 month now (30+ VMs on iSCSI Storage with 3 Nodes) and after we ran into more and more Problems we had many discussions with our team and we had to ask ourselfes what Xen brings to the table that is worth the drawbacks. The only scenario where it fits for us is where we have to map physical hardware into VMs.

We decided to come back in some time to see how the SMAPIv3 drivers work out and if there is a better support for shared storage.

@flakpyro
To be honest we gave up on Xen for our systems where we have shared storage. We swiched to HyperV.

The Lack of CBT Support in CommVault was a major problem. We cannot use XO for backups because it lacks 90% of the features we now have with CommVault (Dedup, Tape, Agents, IntelliSnap of VM disks, AUX Copys,..) and we dont want to combine it with CommVault agents since this complicates our Backups and dies not make real sense.

HyperV with Clustering is free in our setup so it was not a big discussion there. We also can utilize the full potential (performance and feature wise) of our SAN and Network which always was a major issue with Xen.

We keep XCP-NG for now on some specialized installs where we need to map physical hardware into a vm.

@DeOccultist i expected this but my thought is that now you can open a ticket at lenovo because maybe xenserver (not xcp-ng) is on the list of supported os and they will help you.

Maybe someone could try XenServer-8 which might be supported by Lenovo and reopen the ticket again. https://hcl.xenserver.com/servers/?serversupport__version=21&vendor=4&form_factor=2

@olivierlambert i have running a XO installation which does backup a small part of our infrastructure, which works well. it is a single host with local thin-provisioned storage.

we also tried it on our main pool with iscsi storage and had mostly the same problems like others above.

we decided to wait a litte longer before we give it another try on our main production system mainly due to some hanging snapshots,...

in the future we are planning to use it as main vm-level backup solution for standalone hosts in combination with commvault agents in the vm.

our current test status i that we try to use XO as a docker container which would fit better in out existing backup infrastructure as we could easily integrate it in our linux backup appliances (see it like a linux NAS). The docker tests are running very well and we dont have any issues at the moment. even file-level-recovery is working well in this scenario.

@olivierlambert thanks for this info. i also cannot not understand where all the love for proxmox comes from. and thats from someone who has his office in their neighborhood.

@olivierlambert @john-c So i have feedback from commvault. There is an existing Request for Enhancement but no timeline or if it ever will be implemented. The CMR is 346970, for reference

To speed things up there are many more customers needed that reference to this CMR. Thats a chicken-egg problem and i dont think that thats the way to go.

But maybe vates could commmunicate with commvault directly and reference the CMR. For commvault it would be clearly heplful if they could have better numbers about how many customers use XCP-NG and what the potential is.

@nikade
We were also evaluating Dell PowerStore, ME5 (We are Dell and IBM Partners) and Infortrend but all NFS options are simply much to expensive for 90% of our cutomers. We openly discussed it with our major customers which could efford it but they opted for iSCSI and bought just more SSDs. So on new projects we do not really have that much of a problem if we are careful.

On existing customer installations where we have FibreChannel and iSCSI it is different Story.

But i am glad to hear some feedback what others are using and that they are using xen in mission critical environments. often it is not clear what usecase people have and if they are talking about homelab, small non critical systems or something like Oracle VMs, ERP VMs, so serious work.

Thanks

@john-c

okay. you convinced me

i opened a support ticket with a feature request. I will keep you updated on this forum

@olivierlambert
Yes. Unfortunately i dont think that CommVault will add this feature if i request it. And from a bigger perspective where Xen is only on part of many there is no other option for us where we use it today.

For smaller customers we are already evaluating XO with CBT for the VM backups + CommVault Agents in the VM (like others do with veeam)

But we are not entirely convinced that Xen will be our one-fits-all solution for our customers. maybe it will be a combination of hyperv and xenserver/xcp-ng

@olivierlambert

Sorry for that but i am fighting to tune and get backup right for nearly a week now and it is hard to find a real 100% solution. the migration from vmware gives us lots of headaces because of tight storage space and the snapshot problematic

@john-c

I would not compare TrueNAS to IBM, HP, Dell, Netapp,... I have never seen this as a serious storage backend for VmWare or HyperV in a mission-critical environment. And today i have to say that you find this types of environmets in all customer sizes.

TrueNAS is also way more expensive than any IBM FlashSystem

@nikade the probmem wit XO is that you cannot use it if you have multi TB Fileservers or large Mail-Servers and you need Agents to backup Eg.: Oracle, SQL-Server,... . You have to have a backup-solution which integrates with your storage system so that you can attach iscsi volumes directly in the vm.

@rtjdamen

CBT is not supported wit CommVault
CBT is Beta in XO

Other Backup vendors cannot compete when you have a broad spectrum of Agent needs.

@nikade No our current storage does not support nfs. but which enterprise grade-storage beside top end Netapp and Dell PowerStor really do??

@nikade

I tested a backup job just today and we did 5 concurrent vms with about 120-150MB/s each. we use it mostly with XenServer-8 but we also used it with XCP-NG and both are equally supported.

With a singel stream it is hard to get mor than 150MB/s. Downside of backing up multiple vms is that you have many snapshots which cost you much disk-space.

Our backup configruation is a moving target right now because we need to work around the thick-volume snapshot overhead which is very tricky

@john-c
NFS is no solution compared tu fast iSCSI Storage. To get in the performance-range of out ISCSI Flashsystem you have to buy Netapp which costs you three times as much.

If you have to pay this much for a storage to get the same faetures as before you can stay on vmware.

Our three main problems are:

snapshots snapshots snapshots

just a pain on a thick lvm iscsi sr.