GitHub user akrasnov-drv closed a discussion: VM Disk performance issue
Hi, We see degraded performance in our VMs in CloudStack (4.20.0.0) during compilation and other heavy I/O operations. I set our compute offerings to use local disk, nevertheless when there are 20-40 VMs per host, it does not work well. As I understand it happens because of shared base disk architecture used by CloudStack with QCOW images. According to information I found for QCOW: Case-Based Limits: • Light workloads: 10-20 images sharing one base can work fine. • Heavy workloads (e.g., database, high IOPS): Keep it below 5 per base. • Cloud setups (OpenStack, CloudStack): Optimized storage backends (Ceph, LVM) are preferable. Please advise if - there is a way to limit number of images per shared base (or completely change this to independent disks) - there is a way to define compute offering initially with 2 disks - 1st root with shared base from template, 2nd independent and empty. Thanks, Alex. GitHub link: https://github.com/apache/cloudstack/discussions/10468 ---- This is an automatically sent email for users@cloudstack.apache.org. To unsubscribe, please send an email to: users-unsubscr...@cloudstack.apache.org