If the DSM installer runs out of memory after an update, clear the cache here:
http://ip:5000/webman/clean_system_disk.cgi
This usually happens if the system was migrated from DSM 6 to DSM 7.

• If no IP address is assigned during boot, power off and power on the device (avoid reboot).

• Ensure Fastboot/Quiet Boot is disabled in BIOS/UEFI.

• Disable IPv6 and DoT/DoH if you experience connection issues with GitHub, Synology, or DSM installation.

• If your DSM is not visible on the network, try switching the LKM setting from "prod" to "dev"—one may work better depending on your hardware.

If a device (e.g., network card) doesn’t work after boot:

1. Go to Arc Config Mode → Arc Options → Modules → Edit Modules copied to DSM
2. Add a new line above # kvm:
3. For new modules: N YOUR_MODULE.ko (find module name in Arc Config → Sysinfo)
4. To overwrite existing modules (e.g., mlx4_xx.ko, mlx5_xx.ko on SA6400): replace N with F
5. Press TAB to OK and then ENTER

• SAS disks must use block size 512e or 4kn to be recognized.

• Drives require unique serial numbers; conflicts can occur with RAID/SCSI controllers—prefer HBAs over LSI Logic SAS in hypervisors.

• Check Portmap Setting in Arc Config Mode

Synology recommends disabling hibernation to avoid wear from frequent spin-ups and spin-downs—NAS drives are designed for 24/7 operation.
Refer to the Synology tutorial for more details.

• For HP Server with tg3 NIC issues:
  Add N tg3.ko module as described above.

• If DSM won’t boot, try setting Directboot to "true" (required on some HP Microserver).

• For HP P420i controllers, see this tutorial.

• Intel iGPU/GPU (i915) modules are integrated up to 14th Gen Intel CPU / up to Core Ultra 1xx with custom kernel

• AMD iGPU/GPU (amdgpu) modules are integrated up to GCN 5 / up to RDNA 3.5 with custom kernel
• NVIDIA GPU depending on driver version you select to install

Video Compute Runtime DSM App (VCRT)

• Download the base package Video Compute Runtime from DSM App Store -> Community -> Video Compute Runtime (DSM 7.2+)
• Add the support package for your hardware from DSM App Store -> Community -> Video Compute Runtime - Intel or AMD (DSM 7.2+)
• Verify GPU functionality with Arc Control -> System Monitor tab

NVIDIA Driver DSM App

• Use the community driver from DSM App Store -> Community -> NVIDIA Driver (DSM 7.2+)
• Verify GPU functionality with Arc Control -> System Monitor tab

i915 on other model

• Enable i915 addon in Arc Config Mode -> Arc DSM Options -> Addons and rebuild the loader
• Verify GPU functionality with Arc Control -> System Monitor tab

i915 passthrough to Arc VM

Possible cmdline options to add in Arc Config Mode -> DSM Options -> Cmdline:
intel_iommu=on
i915.enable_guc=3
i915.max_vfs=7

• Which model to use?
  See Model Selection Helper in Wiki, only compatible models are shown in the loader.

• Which add-ons to activate?
  Only select add-ons you need (see Add-on Selection in Wiki).

• DSM doesn’t start?
  First boot may take up to 20 minutes. Check Arc Config Mode → Sysinfo for hardware recognition. Consider sharing a screenshot on Discord for help.

• USB drive recognized as internal?
  Check USB Mount Section under Important Options in Wiki.

• Loader offline mode?
  Loader checks internet connectivity at startup. If offline, enable manual offline mode in the menu after verifying network via Networkdiag.

• Update failed?
  Requires stable GitHub connection; try switching DNS to 8.8.8.8 and 8.8.4.4 if issues occur.

• Wrong model selected?
  Change model in Arc Config Mode → Choose Model, then rebuild loader. DSM will prompt migration on next start.

• How to get bootlog data?
  Enable dbgutils addon, rebuild loader, boot DSM, then fetch logs via Arc Config Mode → Loader Options → Grep Logs from dbgutils or visit http://ip:port/webman/get_logs.cgi from recovery.

• Fan Control:
  Adjust temperature and PWM values in Arc Control; wait ~3 minutes for PWM retrain after changing.

• LED Control (for Ugreen):

  • Power LED: Green (<60°C), Yellow (<90°C), Red (>90°C)

  • Network LED: Blue when connected, Red when disconnected and flashing if active

  • Disk LED: Green (<50°C), Yellow (<70°C), Red (>70°C or SMART faults) and flashing if active

• Notifications:
  Supported via Discord and Webhook (Arc Config Mode → Loader Options → Notification Settings).

  • Discord requires registered HardwareID; Webhook always available.

  • Notifications trigger on loader mode changes, DSM startup, SMART warnings, CPU temps >80°C, and drive temps >60°C.

• For all issues and problems: join the Discord Community and follow the guidelines for bug report written in #readme-first 2.2

• No hard drives found?
  Check Arc Config Mode → Sysinfo.

  • DT model don’t support RAID/SCSI/HBA except SA6400 and HBA.

  • Non-DT model may need correct port map settings in Arc Config Mode → Arc DSM Options → SATA Port Map (*recommended option marked with *).

• Which DSM updates are supported?
  Any update supported as long as loader supports the DSM build number (e.g., 69057 U1 to U5). You can switch DSM versions in Arc Config Mode or update directly in DSM.

• Is it possible to downgrade my DSM?
  Yes, it is.
  - Boot to Arc Config Mode
  - Go to Arc Options → DSM Version → Choose DSM Version you want to use.
  - Rebuild the Loader
  - Go to DSM Options  → Allow Downgrade DSM
  - Boot DSM

• Why doesn’t QuickConnect (QC) work?
  Ensure Arc patch is enabled in Arc Config Mode - Arc DSM Options → SN/MAC and use Google DNS inside DSM (some DNS Server block the usage).

• Why does Storage Manager look odd?
  StoragePanel addon adjusts display based on installed drives. Adjust manually via Arc Config Mode → Arc DSM Options → StoragePanel Options.

• CPU frequency scaling not working?
  Supported only on native systems with ACPI enabled in BIOS/UEFI. This will not work for VMs (hypervisor overwrites it).

• Incorrect CPU frequency shown?
  Enable cpuinfo addon for dynamic CPU frequency display.

• Mail Plus Server not working?
  Requires active Arc Patch. Logout from Synology account before restarting.

• Incorrect RAM amount in DSM?
  Requires Ramfix from Arc Loader. Enable it in Arc Config Mode → DSM Options → Cmdline