In short: if using a low-end RAID card (without cache), do yourself a favor and switch to software RAID. If using a mid-to-high-end card (with BBU or NVRAM), then hardware is often (but not always! see below) a good choice. Long answer: when computing power was limited, hardware RAID cards had the significant advantage to … Read more
I use kexec-reboot on nearly all of my production systems. It works incredibly well, allowing me to bypass the long POST time on HP ProLiant servers and reduce the boot cycle from 5 minutes to ~45 seconds. See: https://github.com/error10/kexec-reboot The only caveat is that it doesn’t seem to work on RHEL/CentOS 6.x systems booting UEFI. … Read more
In practice, people who buy from enterprise vendors (HPE, Dell, etc.) do not worry about this. Drives sourced by these vendors are already spread across multiple manufacturers under the same part number. An HP disk under a particular SKU may be HGST or Seagate or Western Digital. Same HP part number, variation on manufacturer, lot … Read more
RAID guards against one kind of hardware failure. There’s lots of failure modes that it doesn’t guard against. File corruption Human error (deleting files by mistake) Catastrophic damage (someone dumps water onto the server) Viruses and other malware Software bugs that wipe out data Hardware problems that wipe out data or cause hardware damage (controller … Read more
RAID: Why and When RAID stands for Redundant Array of Independent Disks (some are taught “Inexpensive” to indicate that they are “normal” disks; historically there were internally redundant disks which were very expensive; since those are no longer available the acronym has adapted). At the most general level, a RAID is a group of disks … Read more