# DRBD 9.3.4 "drbdadm verify" performance

**URL:** https://forums.linbit.com/t/drbd-9-3-4-drbdadm-verify-performance/1279
**Category:** DRBD
**Tags:** drbd
**Created:** [September 23, 2026, 12:10pm UTC](https://forums.linbit.com/t/drbd-9-3-4-drbdadm-verify-performance/1279 "2026-09-23T12:10:43Z")
**Posts on this page:** 1
**Page:** 1

<div class="post-metadata">

### Author: ![Anton](https://avatars.discourse-cdn.com/v4/letter/a/d9b06d/32.png) [@Anton](https://forums.linbit.com/u/Anton)
#### Post date: [September 23, 2026, 12:10pm UTC](https://forums.linbit.com/t/drbd-9-3-4-drbdadm-verify-performance/1279/1 "2026-09-23T12:10:43Z")

</div>

Hello

How to improve “drbdadm verify” with verify-alg crc32c performance between two modern physical servers with AMD Zen5 9455 and PCIe 5.0 NVMe SSDs in RAID0 running on Fedora Server 44 (7.2.7 kernel) ?

The best result I got,

```auto
[2017.119025] drbd no_vdo/99 drbd100 qdevice: Online verify done (total 193 sec; paused 0 sec; 5059584 K/sec)
[2017.119040] drbd no_vdo/99 drbd100 qdevice: repl( VerifyS -> Established ) [resync-finished]

```

```auto
[root@qdevice anton]# cat /etc/drbd.d/no_vdo.res
resource no_vdo {
    options {
        auto-promote no;
    }
    disk {
        c-plan-ahead 0;
        resync-rate 8G;
        c-max-rate 4G;
        c-min-rate 2G;
        al-extents 131072;
        c-fill-target 32M;
    }
    volume 99 {
        device /dev/drbd100;
        disk /dev/vg_test/lvol_no_vdo;
        meta-disk internal;
    }
    on memverge3 {
        node-id 27;
    }
    on qdevice {
        node-id 28;
    }
    net {
        transport tcp;
        protocol C;
        sndbuf-size 64M;
        rcvbuf-size 64M;
        max-buffers 128K;
        max-epoch-size 16K;
        timeout 15;
        ping-timeout 5;
        ping-int 3;
        connect-int 3;
        verify-alg crc32c;
        after-sb-0pri disconnect;
        after-sb-1pri discard-secondary;
        after-sb-2pri disconnect;
        ko-count 21;
    }
    connection {
        path {
            host memverge3 address 1.1.1.3:7919;
            host qdevice address 1.1.1.4:7919;
        }
    }
}
[root@qdevice anton]#

```

```auto
  36.83% [kernel] [k] chksum_update
  20.50% [kernel] [k] crc32_lsb_vpclmul_avx512
  17.15% [kernel] [k] clear_highpages_kasan_tagged
   0.94% [kernel] [k] __free_pages_ok
   0.89% [kernel] [k] native_irq_return_iret
   0.84% [kernel] [k] ktime_get
   0.81% [kernel] [k] rmqueue.isra.0

    PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
   4581 root 20 0 0 0 0 S 28.3 0.0 2:52.51 drbd_s_no_vdo
   4594 root 20 0 0 0 0 S 10.3 0.0 1:03.47 drbd_r_no_vdo
      1 root 20 0 28296 16472 10448 S 0.0 0.0 0:01.38 systemd
      2 root 20 0 0 0 0 S 0.0 0.0 0:00.01 kthreadd
      3 root 20 0 0 0 0 S 0.0 0.0 0:00.00 pool_workqueue_release
      4 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 kworker/R-rcu_gp
      5 root 0 -20 0 0 0 I 0.0 0.0 0:00.00 kworker/R-sync_wq

```