The HP ProLiant MicroServer Gen8 is still a very useful small home server. It works well for TrueNAS, homelab setups, backup targets, or compact storage systems.<\/p>\n
A common issue appears when you want to move away from booting TrueNAS from a USB flash drive and instead use a proper small SSD.<\/p>\n
The MicroServer Gen8 has an internal SATA connector at the top of the chassis. This port was originally intended for an optical DVD drive. It is commonly called the ODD port and is mechanically very convenient for installing a small 2.5-inch SATA SSD.<\/p>\n
The problem: with the four front drive bays populated, the server often does not boot directly from the SSD connected to the ODD port. Without the front drives installed, the SSD boots fine. As soon as the data drives are inserted again, the Gen8 usually tries to boot from The solution: use a small USB stick only as a GRUB bootloader. The actual TrueNAS installation remains on the SSD connected to the ODD port. The USB stick is barely written to and is therefore much less critical than using a USB stick as the full TrueNAS boot device.<\/p>\n The final boot process looks like this:<\/p>\n The USB stick does not contain TrueNAS itself. It only contains GRUB and a small configuration file that starts the bootloader on the SSD.<\/p>\n You need:<\/p>\n In my setup, the SSD on the ODD port appeared to GRUB as:<\/p>\n This can vary depending on drive order and BIOS detection. During the first test, it is useful to try several options or check the available drives from the GRUB console using For TrueNAS, the onboard SATA controller should run in AHCI mode.<\/p>\n AHCI should be enabled. Using the B120i RAID mode is not recommended for TrueNAS. TrueNAS works best when it can access the drives directly.<\/p>\n First, identify the correct USB stick on your Linux system:<\/p>\n Example output:<\/p>\n In this example, the USB stick is:<\/p>\n Warning:<\/strong> The following commands will completely erase the selected device. Make sure you have selected the correct USB stick.<\/p>\n The USB stick is prepared with a classic MBR partition table and a small Linux partition.<\/p>\n Now mount the partition:<\/p>\n The MicroServer Gen8 boots in classic BIOS\/Legacy mode in this setup. Therefore GRUB must explicitly be installed as On Debian, Ubuntu, or Proxmox, install the required package if needed:<\/p>\n Then install GRUB to the USB stick:<\/p>\n Important:<\/p>\n GRUB must be installed to the whole USB stick, not only to the partition.<\/p>\n If you create the stick on a Proxmox system, In that case, use If you see this error:<\/p>\n then the following parameter is usually missing:<\/p>\n Without this parameter, GRUB tries to install an EFI bootloader on a UEFI-booted Linux system. For the MicroServer Gen8 USB chainloader, we need classic BIOS GRUB instead.<\/p>\n Now create the actual GRUB boot configuration:<\/p>\n In my setup, the SSD on the ODD port was detected by GRUB as With this configuration, GRUB waits three seconds and then automatically boots the SSD on the ODD port.<\/p>\n If you do not yet know the correct drive number, you can create several menu entries for testing:<\/p>\n During the first boot, test which entry works. Once the correct entry is known, reduce the If none of the prepared entries work, press Then run:<\/p>\n Example output:<\/p>\n You can then test manually:<\/p>\n If that does not work, try:<\/p>\n Or:<\/p>\n As soon as TrueNAS starts, you have found the correct drive number.<\/p>\n After writing the configuration:<\/p>\n The USB stick can now be inserted into the internal USB port of the MicroServer Gen8.<\/p>\n In the MicroServer Gen8 BIOS:<\/p>\n The internal USB stick should be placed before the hard drives:<\/p>\n The server will then boot GRUB from the USB stick first. GRUB will then start the SSD on the ODD port.<\/p>\n TrueNAS can technically boot from USB sticks, but it is not recommended for long-term reliability. USB sticks are a common source of boot-pool problems, especially with write activity, updates, and ZFS errors.<\/p>\n A better layout is:<\/p>\n In this setup, the USB stick has almost no write activity. Even if it fails at some point, it can easily be recreated. The actual TrueNAS installation remains safely on the SSD.<\/p>\n When an old TrueNAS USB boot stick fails, you may see an error like this:<\/p>\n This usually means that GRUB can no longer find its normal module path or that the boot medium is damaged. If the TrueNAS boot pool also shows checksum errors, it is not worth trying to keep using that USB stick in production.<\/p>\n In that case, reinstalling TrueNAS on an SSD and restoring\/importing the TrueNAS configuration is the cleaner solution.<\/p>\n After successful setup, the boot process looks like this:<\/p>\n This keeps the MicroServer Gen8 fully usable:<\/p>\n This setup is pragmatic, robust, and much better than running the TrueNAS boot pool from an aging USB flash drive. The small GRUB USB stick only acts as a pointer, while the actual system boots properly from the SSD.<\/p>\n","protected":false},"excerpt":{"rendered":" The HP ProLiant MicroServer Gen8 is still a very useful small home server. It works well for TrueNAS, homelab setups, backup targets, or compact storage systems.<\/p>\n A common issue appears when you want to move away from booting TrueNAS from a USB flash drive and instead use a proper small SSD.<\/p>\n The MicroServer Gen8 has an internal SATA connector at the top of the chassis. This port was originally intended for an optical DVD drive. It is commonly called the ODD port and is mechanically very convenient for installing a small 2.5-inch SATA SSD.<\/p>\n","protected":false},"author":1,"featured_media":1685,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[34],"tags":[],"class_list":["post-1689","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news-en"],"yoast_head":"\nHard Drive C:<\/code>, meaning one of the front bay drives.<\/p>\nGoal of the Setup<\/h2>\n
HP MicroServer Gen8 BIOS\r\n \u2193\r\ninternal USB stick with GRUB\r\n \u2193\r\nGRUB chainloads the SSD on the ODD port\r\n \u2193\r\nTrueNAS starts from the SSD\r\n \u2193\r\ndata drives remain in the four front bays<\/code><\/pre>\nRequirements<\/h2>\n
\n
hd5<\/code><\/pre>\nls<\/code>.<\/p>\nImportant: SATA Mode in BIOS<\/h2>\n
F9 \u2192 System Options \u2192 SATA Controller Options<\/code><\/pre>\nPrepare the USB Stick<\/h2>\n
lsblk -o NAME,SIZE,MODEL,TYPE,MOUNTPOINT<\/code><\/pre>\nsda 500G Samsung_SSD disk\r\nsdb 8G USB_Stick disk\r\n\u2514\u2500sdb1<\/code><\/pre>\n\/dev\/sdb<\/code><\/pre>\nPartition and Format the USB Stick<\/h2>\n
sudo umount \/dev\/sdb1 2>\/dev\/null\r\n\r\nsudo wipefs -a \/dev\/sdb\r\n\r\nsudo parted -s \/dev\/sdb mklabel msdos\r\nsudo parted -s \/dev\/sdb mkpart primary ext2 1MiB 100%\r\nsudo parted -s \/dev\/sdb set 1 boot on\r\n\r\nsudo mkfs.ext2 -F -L GRUBGEN8 \/dev\/sdb1<\/code><\/pre>\nsudo mkdir -p \/tmp\/usb\r\nsudo mount \/dev\/sdb1 \/tmp\/usb\r\nsudo mkdir -p \/tmp\/usb\/boot<\/code><\/pre>\nInstall GRUB in Legacy BIOS Mode<\/h2>\n
i386-pc<\/code>.<\/p>\nsudo apt update\r\nsudo apt install grub-pc-bin<\/code><\/pre>\nsudo grub-install \\\r\n --target=i386-pc \\\r\n --boot-directory=\/tmp\/usb\/boot \\\r\n --recheck \\\r\n \/dev\/sdb<\/code><\/pre>\nCorrect: \/dev\/sdb\r\nWrong: \/dev\/sdb1<\/code><\/pre>\nSpecial Case: Proxmox<\/h2>\n
grub-install<\/code> may be blocked by proxmox-boot-tool<\/code>. You may see a message saying that grub-install<\/code> is disabled.<\/p>\ngrub-install.real<\/code> directly:<\/p>\nsudo \/usr\/sbin\/grub-install.real \\\r\n --target=i386-pc \\\r\n --boot-directory=\/tmp\/usb\/boot \\\r\n --recheck \\\r\n \/dev\/sdb<\/code><\/pre>\ncannot find EFI directory<\/code><\/pre>\n--target=i386-pc<\/code><\/pre>\nCreate the GRUB Configuration<\/h2>\n
sudo nano \/tmp\/usb\/boot\/grub\/grub.cfg<\/code><\/pre>\nhd5<\/code>. Therefore the final configuration looks like this:<\/p>\nset timeout=3\r\nset default=0\r\n\r\nmenuentry \"TrueNAS SSD on ODD Port - hd5\" {\r\n insmod chain\r\n set root=(hd5)\r\n chainloader +1\r\n boot\r\n}<\/code><\/pre>\nAlternative Test Configuration<\/h2>\n
set timeout=10\r\nset default=0\r\n\r\nmenuentry \"TrueNAS SSD on ODD Port - hd4\" {\r\n insmod chain\r\n set root=(hd4)\r\n chainloader +1\r\n boot\r\n}\r\n\r\nmenuentry \"TrueNAS SSD on ODD Port - hd5\" {\r\n insmod chain\r\n set root=(hd5)\r\n chainloader +1\r\n boot\r\n}\r\n\r\nmenuentry \"TrueNAS SSD on ODD Port - hd3\" {\r\n insmod chain\r\n set root=(hd3)\r\n chainloader +1\r\n boot\r\n}\r\n\r\nmenuentry \"GRUB Shell\" {\r\n echo \"Press 'c' to open the GRUB console.\"\r\n echo \"Use 'ls' to list detected drives.\"\r\n sleep 5\r\n}<\/code><\/pre>\ngrub.cfg<\/code> to that single entry and set the timeout to three seconds.<\/p>\nManually Check GRUB Drives<\/h2>\n
c<\/code> in the GRUB menu to open the GRUB console.<\/p>\nls<\/code><\/pre>\n(hd0) (hd1) (hd2) (hd3) (hd4) (hd5)<\/code><\/pre>\nset root=(hd5)\r\nchainloader +1\r\nboot<\/code><\/pre>\nset root=(hd4)\r\nchainloader +1\r\nboot<\/code><\/pre>\nset root=(hd3)\r\nchainloader +1\r\nboot<\/code><\/pre>\nUnmount the USB Stick Cleanly<\/h2>\n
sync\r\nsudo umount \/tmp\/usb<\/code><\/pre>\nSet the BIOS Boot Order<\/h2>\n
F9 \u2192 System Options \u2192 Boot Options<\/code><\/pre>\n1. USB DriveKey \/ Internal USB\r\n2. Hard Drive C:\r\n3. Network Boot<\/code><\/pre>\nWhy Not Boot TrueNAS Directly from a USB Stick?<\/h2>\n
TrueNAS system: SSD\r\nUSB stick: only GRUB bootloader\r\nData: separate ZFS data drives<\/code><\/pre>\nError Example: GRUB Rescue \/ normal.mod not found<\/h2>\n
GRUB loading..\r\nWelcome to GRUB!\r\n\r\nerror: file 'normal.mod' not found.\r\ngrub rescue><\/code><\/pre>\nFinal Result<\/h2>\n
MicroServer Gen8 starts\r\nUSB-GRUB appears briefly for 3 seconds\r\nGRUB starts hd5\r\nTrueNAS boots from the SSD on the ODD port\r\nData drives remain untouched in the front bays<\/code><\/pre>\n4 front bays for data drives\r\nODD port for the TrueNAS boot SSD\r\ninternal USB port only for GRUB\r\nAHCI mode for clean TrueNAS operation<\/code><\/pre>\nConclusion<\/h2>\n