# Slow performance **URL:** \ **Category:** General\ **Tags:** drbd\ **Created:** [June 4, 2026, 12:16pm UTC](https://forums.linbit.com/t/slow-performance/1224 "2026-06-04T12:16:02Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Savory](https://avatars.discourse-cdn.com/v4/letter/s/ccd318/32.png) [@Savory](https://forums.linbit.com/u/Savory)\ **Post date:** [June 4, 2026, 12:16pm UTC](https://forums.linbit.com/t/slow-performance/1224/1 "2026-06-04T12:16:02Z")
Hello, I’m running a virtualized infrastructure with Proxmox. It’s equipped with Dell servers and a 10Gbps network interface for DRBD synchronization. HDD SAS on PERC. There’s one VM on each Proxmox server, with a primary node and a secondary node. Protocol C is used. The 10Gbps interfaces are Proxmox Bridges. When the primary node isn’t connected to secondary node, disk performance is acceptable (fio): r=2512MiB/s,w=2517MiB/s As soon as the secondary node is connected to the interface, disk performance drops dramatically: r=84MiB/s,w=52MiB/s Do you have any ideas? Thanks. ---
**Author:** ![Devin](https://yyz1.discourse-cdn.com/flex003/user_avatar/forums.linbit.com/devin/32/26_2.png) [@Devin](https://forums.linbit.com/u/Devin)\ **Post date:** [June 8, 2026, 7:39pm UTC](https://forums.linbit.com/t/slow-performance/1224/2 "2026-06-08T19:39:45Z")
DRBD can really only operate as fast as the slowest bottle-neck. In cases like this there is likely a bottle-neck somewhere. How fast is the disk in the peer? Can you test its performance while also disconnected? Can you confirm the network is running at 10gb (~1100/MiB)? What is the network latency between the hosts like (ping RTT)? ---
**Author:** ![Savory](https://avatars.discourse-cdn.com/v4/letter/s/ccd318/32.png) [@Savory](https://forums.linbit.com/u/Savory)\ **Post date:** [June 9, 2026, 6:09am UTC](https://forums.linbit.com/t/slow-performance/1224/3 "2026-06-09T06:09:04Z")
On the peer, it’s a 6Gb/s SAS HDD on a PERC card. Disconnected performance is around ~3000/MiB with BBU caching. I can confirm that I’m achieving 10Gbps via iperf3. And ping \<1ms. The network connection is peer-to-peer with no intermediate equipment.