R1Soft's Server Backup agent does block-level CDP via a kernel module (hcpdriver). When the agent starts and the module is missing or mismatched, serverbackup-setup --get-module returns no suitable hcpdriver module found for kernel <version> and backups fail at the disk safe stage. The fix is almost always one of four things, in this order.
1. Align kernel and kernel-devel
The agent builds — or downloads a prebuilt match for — the exact kernel currently booted. A common cause is a yum update that pulled a newer kernel without the matching kernel-devel, or a kernel-devel left behind from a previous boot.
uname -r
rpm -q kernel-devel
If the two versions differ, install the matching kernel-devel:
yum install kernel-devel-$(uname -r)
If yum cannot find that exact version, your repo cache is stale or the kernel was pinned. Re-enable the base repo and retry. Do not reboot into a different kernel just to satisfy the build — fix the userspace first.
2. Refetch the prebuilt module
R1Soft maintains prebuilt hcpdriver modules for thousands of distro/kernel combinations on krnlbld.r1soft.com. The agent fetches one automatically:
serverbackup-setup --get-module
If this fails with a network error, your egress firewall is blocking krnlbld.r1soft.com on port 443. Open it. Many fleets that route through a squid proxy or restrictive cloud security group hit this first on a new build:
curl -sI https://krnlbld.r1soft.com/ | head -1
A 200 or 301 response means egress is clear. A timeout means open it on the firewall and retry.
3. Pull a beta module
If the prebuilt index does not yet have your kernel — usually within 24-48 hours of a fresh AlmaLinux, CloudLinux, or RHEL kernel release — request the beta:
serverbackup-setup --get-module --beta
Beta modules are built from the same source but have not been through R1Soft QA. In production they are almost always fine; revert to stable on the next agent restart once the public index catches up.
4. Fall back to DKMS build
If no prebuilt or beta exists (rare custom kernels, ELRepo kernel-ml, or hardened builds), build locally. Install the toolchain first:
yum install -y dkms kernel-headers-$(uname -r) gcc make perl
serverbackup-setup --get-module
The agent invokes dkms automatically when no prebuilt match is found. A local build adds 30-60 seconds to the first run and writes the module under /usr/lib/r1soft/kernel_modules/.
Verify the module loaded
lsmod | grep hcp
service cdp-agent restart
service cdp-agent status
You want hcpdriver in the lsmod output and the agent reporting running. From the Server Backup Manager, trigger a manual recovery point — it should advance past the "Mounting disk safe" stage that previously failed.
For a clean install from scratch on a new node, see installing the R1Soft agent on AlmaLinux. If you're still evaluating R1Soft against your existing tooling, the R1Soft vs JetBackup comparison covers where each one earns its keep.
Why does serverbackup-setup say no suitable hcpdriver module?+
How do I open krnlbld.r1soft.com in my firewall?+
Is it safe to use the R1Soft beta hcpdriver module in production?+
Do I need to rebuild the hcpdriver after every kernel update?+
Will DKMS handle the hcpdriver rebuild automatically?+
Next steps
- Install fresh on AlmaLinux: R1Soft agent install guide.
- Replicate off-site: Disk Safe replication setup.
- Buy or renew: R1Soft license.