VM cloning is slow

[srmvel]

Hi Team,

We have a slow response while taking the Windows clone.

Let me explain our setup.

7 Proxmox nodes ceph storage cluster
Each node has 5 * 2 TB Crucial 500 SSD drives.
2 * 40 GB NIC goes to public network/cluster network.
2 * 10 G NIC goes to VM network/migration network.
2 * 1 G NIC goes to Corosync & Proxmox management.
Replica size & mini size is 2/2


When we take the multiple Windows clone(100 G size) at the same time(lets say 5 counts),its taking 20 to 25 minutes.

Also we notice the clone goes faster sometimes to 100 % and then its taking much time to complete the final sync.

Do we have any specific recommendations for Ceph to increase the performance?

We did these only sofar from command line.

echo 2048 > /sys/block/sda/queue/read_ahead_kb
echo 2048 > /sys/block/sdb/queue/read_ahead_kb
echo 2048 > /sys/block/sdc/queue/read_ahead_kb
echo 2048 > /sys/block/sdd/queue/read_ahead_kb
cat /sys/block/sda/queue/read_ahead_kb


We cannot add noop( delivers better performance for SSDs).Getting error while adding this.

We have so many recommmdations from the below link and not sure what are all the parameters are really required to gain the performance?

https://tracker.ceph.com/projects/c...l_Flash_Deployments#Ceph-Client-Configuration


Thanks,
Raj

 

[spirit]

Do we have any specific recommendations for Ceph to increase the performance?

use datacenter grade ssd ... crucial 500 are pretty shitty for write

https://www.sebastien-han.fr/blog/2...-if-your-ssd-is-suitable-as-a-journal-device/

 

[spirit]

or use linked clone, it could help in your case

 

[srmvel]

ok thanks. The requirement is specific to the full clone.

Do you have any other recommendations to increase perf?

 

[Magneto]

or use linked clone, it could help in your case

please explain, what is a linked clone?

 

[bbgeek17]

https://pve.proxmox.com/wiki/VM_Templates_and_Clones

• Linked Clone - A linked clone VM requires less disk space but cannot run without access to the base VM Template

Linked Clone​

A linked clone VM requires less disk space but cannot run without access to the base VM Template.

Linked Clones works for theses storages: files in raw, qcow2, vmdk format (either on local storage or nfs); LVM-thin, ZFS, rbd, sheepdog, nexenta.

It's not supported with LVM & ISCSI storage.

Note that with Blockbridge iSCSI storage Linked Clones are supported https://kb.blockbridge.com/guide/proxmox/#proxmox-ve-storage-guide

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Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox