https://maxdoubin.com/blog Writing on cybersecurity, enterprise networking, and systems infrastructure. en-us Sat, 17 Oct 2026 12:00:00 GMT https://maxdoubin.com/blog/dell-hba330-vs-h330 https://maxdoubin.com/blog/dell-hba330-vs-h330 Sat, 17 Oct 2026 12:00:00 GMT Which card to buy for ZFS or TrueNAS: the H330 has RAID and no cache, the HBA330 is non-RAID. Dell's queue depths, PowerEdge fit and crossflash risks. https://maxdoubin.com/blog/do-you-need-a-sas-expander-homelab https://maxdoubin.com/blog/do-you-need-a-sas-expander-homelab Sat, 17 Oct 2026 12:00:00 GMT An HBA connects drives directly, while an expander adds drive ports and shares one SAS link. Here is the bandwidth math and when a homelab needs one. https://maxdoubin.com/blog/fortios-7-6-vs-7-4 https://maxdoubin.com/blog/fortios-7-6-vs-7-4 Sat, 17 Oct 2026 12:00:00 GMT Which small FortiGates lose SSL VPN on 7.6, which stay on 7.4, how long each branch is supported, and the build Fortinet recommends for the 40F, 60F, 70G and 90G. https://maxdoubin.com/blog/fortiwifi-40f-vs-fortigate-40f https://maxdoubin.com/blog/fortiwifi-40f-vs-fortigate-40f Sat, 17 Oct 2026 12:00:00 GMT The FortiWiFi 40F is the FortiGate 40F with one radio, a higher power draw and the same ports, processor and rated throughput. Here is what to check before you buy. https://maxdoubin.com/blog/idrac-10-vs-idrac-9 https://maxdoubin.com/blog/idrac-10-vs-idrac-9 Sat, 17 Oct 2026 12:00:00 GMT iDRAC10 on 17th generation PowerEdge cuts four license tiers to three, removes WSMan and Group Manager, and defaults to TLS 1.3 with SNMP off. Here is what changes for licenses and tools. https://maxdoubin.com/blog/idrac-6-express-vs-enterprise https://maxdoubin.com/blog/idrac-6-express-vs-enterprise Sat, 17 Oct 2026 12:00:00 GMT Express has no remote console. Enterprise adds the virtual console, virtual media and a dedicated port. Here is how to test which tier your iDRAC6 has, and what breaks. https://maxdoubin.com/blog/ilo-6-vs-ilo-7 https://maxdoubin.com/blog/ilo-6-vs-ilo-7 Sat, 17 Oct 2026 12:00:00 GMT Gen11 servers run iLO 6 and Gen12 servers run iLO 7. Learn which generation gets each controller, how security and licensing differ, and what changes for management. https://maxdoubin.com/blog/lsi-9207-8i-vs-9211-8i https://maxdoubin.com/blog/lsi-9207-8i-vs-9211-8i Sat, 17 Oct 2026 12:00:00 GMT SAS2308 vs SAS2008, PCIe 3.0 vs 2.0 limits, what IT firmware changes, measured speeds, and which card to buy for a ZFS or TrueNAS pool. https://maxdoubin.com/blog/lsi-9300-8i-cooling https://maxdoubin.com/blog/lsi-9300-8i-cooling Sat, 17 Oct 2026 12:00:00 GMT Why the LSI 9300-8i runs hot, the airflow Broadcom specifies, how overheating shows up in a quiet case, and how to add a fan without blocking the heat sink. https://maxdoubin.com/blog/mac-pro-2019-gpu-upgrade https://maxdoubin.com/blog/mac-pro-2019-gpu-upgrade Sat, 17 Oct 2026 12:00:00 GMT Every graphics MPX module Apple sold for the 2019 Mac Pro, the 300W and 305mm limits on standard cards, which GPUs macOS drives, and what to check before buying used. https://maxdoubin.com/blog/mac-pro-5-1-max-ram https://maxdoubin.com/blog/mac-pro-5-1-max-ram Sat, 17 Oct 2026 12:00:00 GMT Apple's limit is 32GB on a single-processor tray and 64GB on a dual tray. Here is what owners run past it, with the module, speed and macOS rules. https://maxdoubin.com/blog/mac-pro-7-1-cpu-upgrade https://maxdoubin.com/blog/mac-pro-7-1-cpu-upgrade Sat, 17 Oct 2026 12:00:00 GMT Which Xeon W chips a 2019 Mac Pro 7,1 accepts, what the socket and fans allow, and whether a 16-, 24- or 28-core swap is worth it. https://maxdoubin.com/blog/netapp-ds4246-truenas https://maxdoubin.com/blog/netapp-ds4246-truenas Sat, 17 Oct 2026 12:00:00 GMT Cable a NetApp DS4246 to TrueNAS with an LSI HBA, reformat its 520-byte drives to 512, and avoid the SMART and pool faults owners report on SCALE. https://maxdoubin.com/blog/perc-h755-hba-mode https://maxdoubin.com/blog/perc-h755-hba-mode Sat, 17 Oct 2026 12:00:00 GMT Dell's documents show no HBA mode for the PERC H755. Here is what per-disk Non-RAID gives you, why some guides claim eHBA, and which card to buy instead. https://maxdoubin.com/blog/poweredge-r540-vs-r740 https://maxdoubin.com/blog/poweredge-r540-vs-r740 Sat, 17 Oct 2026 12:00:00 GMT The R540 fits 14 3.5-inch drives, while the R740 takes 24 DIMMs and up to three double-wide GPUs. Here are the bay, slot and memory limits for each. https://maxdoubin.com/blog/proliant-dl360p-gen8-fan-noise https://maxdoubin.com/blog/proliant-dl360p-gen8-fan-noise Sat, 17 Oct 2026 12:00:00 GMT Why a DL360p Gen8 runs loud fans at idle: unreadable drives, PCIe cards, firmware bugs and missing fan blanks, plus how to read iLO 4 and which fixes to try. https://maxdoubin.com/blog/replace-idrac-ssl-certificate https://maxdoubin.com/blog/replace-idrac-ssl-certificate Sat, 17 Oct 2026 12:00:00 GMT Generate a CSR with the iDRAC name in the CN and SAN, upload the key and certificate with racadm, and avoid the firmware changes that revert them. https://maxdoubin.com/blog/smart-array-p420i-hba-mode https://maxdoubin.com/blog/smart-array-p420i-hba-mode Sat, 17 Oct 2026 12:00:00 GMT Enable HBA mode on a Smart Array P420i with ssacli, the firmware owners report, why boot fails from those disks, and what ZFS needs. https://maxdoubin.com/blog/supermicro-x10-vs-x11 https://maxdoubin.com/blog/supermicro-x10-vs-x11 Sat, 17 Oct 2026 12:00:00 GMT X10 and X11 each cover at least two sockets. Compare CPU socket, memory ceiling, NVMe boot and IPMI before you buy a used Supermicro server board. https://maxdoubin.com/blog/used-catalyst-9300-for-a-lab https://maxdoubin.com/blog/used-catalyst-9300-for-a-lab Sat, 17 Oct 2026 12:00:00 GMT Buying a used Cisco Catalyst 9300 for a lab? Check the license suffix, the Smart Account, the stack cables, the power supplies and the enable password first. https://maxdoubin.com/blog/idrac-fan-speed-offset https://maxdoubin.com/blog/idrac-fan-speed-offset Mon, 05 Oct 2026 12:00:00 GMT Learn what each iDRAC9 thermal setting does on an R640 or R740, with exact racadm and Redfish commands, per-slot PCIe cooling and the firmware change that ended raw IPMI fan control. https://maxdoubin.com/blog/perc-h730-hba-mode https://maxdoubin.com/blog/perc-h730-hba-mode Mon, 05 Oct 2026 12:00:00 GMT How to switch a PERC H730, H730P or H330 to HBA mode from System Setup or iDRAC, what it changes for drivers, cache and SMART, and when an HBA330 is the better fix for ZFS. https://maxdoubin.com/blog/idrac-9-enterprise-license https://maxdoubin.com/blog/idrac-9-enterprise-license Mon, 05 Oct 2026 12:00:00 GMT What each iDRAC9 license tier unlocks, how to check and trial a license, what Dell charges for Enterprise, and how licenses bind to a service tag. https://maxdoubin.com/blog/dell-r720-power-consumption https://maxdoubin.com/blog/dell-r720-power-consumption Mon, 05 Oct 2026 12:00:00 GMT Measured idle and full-load watts for the Dell R720 from SPEC, Dell and reviewers, a yearly cost table at the EIA's July 2026 US rate, and how to measure and cut the draw. https://maxdoubin.com/blog/idrac-default-password https://maxdoubin.com/blog/idrac-default-password Mon, 05 Oct 2026 12:00:00 GMT Older iDRACs use root and calvin, while iDRAC9 and iDRAC10 print a unique password on the pull-out tag. Find it, the default IP and ports, and every supported way to reset it. https://maxdoubin.com/blog/dell-r730-gpu-enablement-kit https://maxdoubin.com/blog/dell-r730-gpu-enablement-kit Mon, 05 Oct 2026 12:00:00 GMT What Dell's R730 GPU enablement kit contains, the power, slot and cooling rules, the cards Dell lists, and how to check the riser power cable before you power on. https://maxdoubin.com/blog/mac-pro-4-1-vs-5-1 https://maxdoubin.com/blog/mac-pro-4-1-vs-5-1 Mon, 05 Oct 2026 12:00:00 GMT A Mac Pro 4,1 and 5,1 differ mainly in the CPU tray. See what the 4,1 to 5,1 firmware flash changes and leaves alone, how it is done, and which to buy used. https://maxdoubin.com/blog/mac-pro-6-1-latest-os https://maxdoubin.com/blog/mac-pro-6-1-latest-os Mon, 05 Oct 2026 12:00:00 GMT The 2013 Mac Pro officially tops out at macOS Monterey 12.7.6, last patched July 29, 2024. See what OpenCore Legacy Patcher adds after it, what breaks, and what to run. https://maxdoubin.com/blog/linux-on-mac-pro-6-1 https://maxdoubin.com/blog/linux-on-mac-pro-6-1 Mon, 05 Oct 2026 12:00:00 GMT How to install Linux on the 2013 Mac Pro 6,1: which kernels run the FirePro D300, D500 and D700 on amdgpu, Broadcom Wi-Fi, fan behavior, Thunderbolt 2 and Proxmox. https://maxdoubin.com/blog/mac-mini-home-server-setup https://maxdoubin.com/blog/mac-mini-home-server-setup Mon, 05 Oct 2026 12:00:00 GMT Set up a Mac mini as an always-on home server: sleep and power-failure settings, the FileVault trade-off, remote access, containers, file sharing and what breaks. https://maxdoubin.com/blog/mac-pro-5-1-latest-os https://maxdoubin.com/blog/mac-pro-5-1-latest-os Mon, 05 Oct 2026 12:00:00 GMT Apple stopped at macOS Mojave for the 2010 and 2012 Mac Pro. See what OpenCore Legacy Patcher adds up to Sequoia, what breaks at each step, and which version to run. https://maxdoubin.com/blog/opencore-legacy-patcher-tahoe https://maxdoubin.com/blog/opencore-legacy-patcher-tahoe Mon, 05 Oct 2026 12:00:00 GMT OCLP 3.0.0 release candidates add macOS Tahoe support, but only as pre-releases. See which Macs work, what breaks, how to update safely and what macOS 27 means. https://maxdoubin.com/blog/fortigate-homelab-license https://maxdoubin.com/blog/fortigate-homelab-license Mon, 05 Oct 2026 12:00:00 GMT What a used FortiGate still does with no FortiCare contract, why Fortinet refuses most secondhand transfers, and the exact limits of the free FortiGate-VM trial. https://maxdoubin.com/blog/fortigate-60e-to-60f-migration https://maxdoubin.com/blog/fortigate-60e-to-60f-migration Mon, 05 Oct 2026 12:00:00 GMT How to move a FortiGate 60E config to a 60F before support ends December 29, 2026: matching FortiOS 7.4, free FortiConverter, header edits, port renames and licenses. https://maxdoubin.com/blog/dell-boss-card https://maxdoubin.com/blog/dell-boss-card Mon, 05 Oct 2026 12:00:00 GMT What Dell's Boot Optimized Storage Solution is for, how the BOSS-S1, S2 and N1 differ, which PowerEdge servers take each, and how to replace a failed M.2. https://maxdoubin.com/blog/truenas-on-dell-r730 https://maxdoubin.com/blog/truenas-on-dell-r730 Mon, 05 Oct 2026 12:00:00 GMT How to build a TrueNAS box on a Dell R730 or R730xd: which PERC or HBA passes disks to ZFS, where the boot pool goes, memory, networking and fan noise. https://maxdoubin.com/blog/poweredge-r740-end-of-life https://maxdoubin.com/blog/poweredge-r740-end-of-life Mon, 05 Oct 2026 12:00:00 GMT Last order, warranty, firmware and EOSL dates for the PowerEdge R740 and R640, with the R730 and R630, what keeps working after each, and what to buy next. https://maxdoubin.com/blog/dell-r730-vs-r730xd https://maxdoubin.com/blog/dell-r730-vs-r730xd Mon, 05 Oct 2026 12:00:00 GMT What the R730 and R730xd share, every drive bay, PCIe slot and GPU difference from Dell's documents, and which one to buy for a ZFS box or a GPU host. https://maxdoubin.com/blog/dell-r730-quiet-fans https://maxdoubin.com/blog/dell-r730-quiet-fans Mon, 05 Oct 2026 12:00:00 GMT What makes an R730 loud, which iDRAC8 settings actually lower fan speed, the raw IPMI override byte by byte, and a watchdog that hands control back when temperatures climb. https://maxdoubin.com/blog/linux-on-mac-pro-7-1 https://maxdoubin.com/blog/linux-on-mac-pro-7-1 Mon, 05 Oct 2026 12:00:00 GMT How to run Linux on a 2019 Mac Pro: the Startup Security settings, t2linux kernels, what the SSD, Wi-Fi, 10GbE and AMD GPUs need, and what still breaks. https://maxdoubin.com/blog/windows-11-on-mac-pro-7-1 https://maxdoubin.com/blog/windows-11-on-mac-pro-7-1 Mon, 05 Oct 2026 12:00:00 GMT Windows 11 is not supported on the 2019 Mac Pro, but it installs. What the T2 and TPM mean, which install routes work, the right drivers, and the Windows 10 ESU option. https://maxdoubin.com/blog/macos-tahoe-on-mac-pro-7-1 https://maxdoubin.com/blog/macos-tahoe-on-mac-pro-7-1 Mon, 05 Oct 2026 12:00:00 GMT The 2019 Mac Pro runs macOS Tahoe 26 and nothing newer. What Apple has said about security updates, what Tahoe leaves out on Intel, and your options after it. https://maxdoubin.com/blog/mac-pro-5-1-vs-7-1 https://maxdoubin.com/blog/mac-pro-5-1-vs-7-1 Mon, 05 Oct 2026 12:00:00 GMT Compare the 2010 to 2012 Mac Pro 5,1 with the 2019 7,1 on speed, memory, PCIe, GPUs, power, macOS support and used prices, using benchmarks from one source. https://maxdoubin.com/blog/apple-server-hardware https://maxdoubin.com/blog/apple-server-hardware Mon, 05 Oct 2026 12:00:00 GMT From the 1993 Workgroup Server through the Xserve, the rack Mac Pro and the Apple silicon servers Apple now builds for itself: every Apple server line, with dates and what each one could do. https://maxdoubin.com/blog/macos-server-versions https://maxdoubin.com/blog/macos-server-versions Mon, 05 Oct 2026 12:00:00 GMT Every macOS Server release from Mac OS X Server 1.0 in 1999 to the final 5.12.2, which macOS each version needs, what Apple removed along the way, and what replaces it. https://maxdoubin.com/blog/the-memory-you-freed-and-still-hold https://maxdoubin.com/blog/the-memory-you-freed-and-still-hold Sun, 20 Sep 2026 12:00:00 GMT free() returned twenty megabytes to the kernel in one measurement and nothing at all in the next, and the only difference was one surviving kilobyte. Then a sixteen mebibyte allocation at startup switched the automatic trim off for the rest of the process, and a thirty three mebibyte one did not. https://maxdoubin.com/blog/even-is-not-stable https://maxdoubin.com/blog/even-is-not-stable Sun, 20 Sep 2026 12:00:00 GMT SO_REUSEPORT spreads connections evenly across every listener, at every worker count, on every run. That is the half everybody measures. The other half is that changing the worker count sends a large share of clients to a different worker, and it is why a rolling restart drops handshakes while every process looks healthy. https://maxdoubin.com/blog/three-alignments-and-one-errno https://maxdoubin.com/blog/three-alignments-and-one-errno Sun, 20 Sep 2026 12:00:00 GMT An O_DIRECT write returns EINVAL. Three separate things have to be aligned and all three failures report the same errno, so the return value tells you nothing. One of the three is not the rule you think it is: a misaligned buffer works until the transfer leaves its page. https://maxdoubin.com/blog/the-cache-you-cannot-drop https://maxdoubin.com/blog/the-cache-you-cannot-drop Sun, 20 Sep 2026 12:00:00 GMT A gibibyte written to a file and a gibibyte written to tmpfs put the same figure in free's buff/cache column. Dropping caches returns the first and none of the second. The only field in the output that tells them apart is the one labeled shared, which nobody reads. https://maxdoubin.com/blog/one-descriptor-too-many https://maxdoubin.com/blog/one-descriptor-too-many Sun, 20 Sep 2026 12:00:00 GMT FD_SET is one division and one store, with no check anywhere in it. An fd_set is 128 bytes, so descriptor 1024 is byte 128, and what is at byte 128 is whatever member of your struct the compiler put after the set. A week of uptime is all it takes.