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> > This is in fact one of the very few places where Hardware RAID solutions can have an edge over Software solutions - if you use a hardware RAID card, the ext

> > This is in fact one of the very few places where Hardware RAID solutions can have an edge over Software solutions - if you use a hardware RAID card, the extra write copies of the data will not have to go over the PCI bus, since it is the RAID controller that will generate the extra copy. This is not a thing to bother (especially after we moved from PCI to PCI-E) for a home user. The only great thing about HW RAID is what in case your primary drive fail-but-not-fail-completely, ie it would still be seen in the BIOS and BIOS would try to boot from it (but it wouldn't be able to, because drive is half-dead) is what for the BIOS a controller presents a single device and so it would allow booting from a healthy drive. But again, if this is not a server in a remote oil digging site served twice a year by air (been there, done that) this is not a thing to bother for a home user. > the possibility of the hardware controller failing is a worry, so I’d need to have a backup strategy for the backup disks If you use a basic mirror (striped or not) the recovery process is straightforward - for a simple mirror just stick it in any other system/controller, for a striped you would need GetDataBack or R-Studio or just find a newer model of the RAID card from the same vendor. In your case I would advise to have a single disk in the ODD bay as a boot/system drive and use both your HDDs as an LVM PVs, without fdisk shenanigans. If you/when you decide to upgrade/replace disks the migration would be just a couple of commands like pvcreate /dev/sdc vgextend your_vg /dev/sdc pvmove /dev/mapper/your_vg__your_lv /dev/sda /dev/sdc vgreduce /dev/sda

Anthony-G 4y ago
Wow! That's all really informative. I had thought that a non-striped, mirrored disk should be usable if the H/W RAID controller failed (given that all the data is stored on the disk) but I didn’t know for sure. I didn’t think it would also be possible to recover striped disks. Thanks for the great advice on using LVM and the commands for replacing a disk. I only recently cane across a system that used the disk block device itself as a physical volume – rather than partitioning it via fdisk or parted. Other than using LVM for creating snapshots, I haven't really used it for anything interesting.
- justsomehnguy 4y ago
  > but I didn’t know for sure The array metadata is just stored at the end of the disk, so this is not a problem to just attach a disk somewhere rlse > commands for replacing a disk Take it with a grain of salt, I just wrote them from memory. But the overall process is exactly as I said. Glad you found that helpful.

Anthony-G 4y ago

Wow! That's all really informative. I had thought that a non-striped, mirrored disk should be usable if the H/W RAID controller failed (given that all the data is stored on the disk) but I didn’t know for sure. I didn’t think it would also be possible to recover striped disks. Thanks for the great advice on using LVM and the commands for replacing a disk. I only recently cane across a system that used the disk block device itself as a physical volume – rather than partitioning it via fdisk or parted. Other than using LVM for creating snapshots, I haven't really used it for anything interesting.

justsomehnguy 4y ago
> but I didn’t know for sure The array metadata is just stored at the end of the disk, so this is not a problem to just attach a disk somewhere rlse > commands for replacing a disk Take it with a grain of salt, I just wrote them from memory. But the overall process is exactly as I said. Glad you found that helpful.