There, I have a significant choice — to use the on-board RAID, or do it entirely in software (e.g. OpenMediaVault)?
If you use hardware RAID -- especially one built-in to a motherboard -- and the hardware dies, you're screwed. Using software RAID, like the LVM Raid Linux provides, makes your RAID configuration hardware independent allowing you to move your disks to another system as you want/need. If you decide to use HW RAID, get a well-known dedicated RAID card that you can replace more easily than the motherboard with built-in RAID.
Still, there is a lot to be said for some of the off-the-shelf home RAID boxes. I haven't researched them, but I know a friend like the Synology NAS boxes. Most of those types of solutions are really Linux systems, but whether it's really software or hardware, I don't know, so I don't know if you could pull the drives and use Linux to recover your data. That should be a standard question to ask vendors before purchasing, but I doubt many people consider it.
My Synology box (which is indeed a Linux box) has been humming along for over a decade now. Synology uses software RAID. They've implemented their own solution which lets you mix and match different sized disks, and it will intelligently make use of all the extra space (assuming you're using three or more disks). This lets you increase your RAID disks over time, a feature I've taken advantage of over the years as disk sizes have increased, while prices have come down.
I've had a couple of drives fail over that time, and I ordered new, larger drives for replacements. The replacement procedure was easy, as the drives are mounted in front of the box, and are hot-swappable. So pop the old one out, mount and push the new one in, then use the configuration control panel and tell it to rebuild the drive array using the new drive. After x hours of formatting and copying data, the job is done, with zero downtime.
if someone wants a NAS box, I'll always recommend Synology.
I believe Synology also makes it possible to recover data in case of hardware failure - either using another synology device, or using a special Linux distirbution that can mount all the disks.
Data protection is key - disk failure is the most likely cause of data loss, so RAID helps protect against it. However, you also want to protect against hardware failure - if the RAID hardware fails, how would you recover from that? Motherboard RAID is only recoverable in RAID1 (mirroring) mode - basically stick it in
Well, in theory. According to their docs you can recover an array by finding a desktop with enough SATA ports and booting it from an Ubuntu stick. Everything is done with MADM and LVM, so it should work. The one time I had to do it, it didn't work out so well. Possibly because there was a combination of an almost-dead drive and a pair of cache SSDs. It was simply not possible to mount or repair the array. The only thing that got us back up with all our data was replacement hardware, which worked immed
"The pyramid is opening!"
"Which one?"
"The one with the ever-widening hole in it!"
-- The Firesign Theatre
Software RAID (Score:5, Informative)
There, I have a significant choice — to use the on-board RAID, or do it entirely in software (e.g. OpenMediaVault)?
If you use hardware RAID -- especially one built-in to a motherboard -- and the hardware dies, you're screwed. Using software RAID, like the LVM Raid Linux provides, makes your RAID configuration hardware independent allowing you to move your disks to another system as you want/need. If you decide to use HW RAID, get a well-known dedicated RAID card that you can replace more easily than the motherboard with built-in RAID.
Re: (Score:2)
THIS!
Still, there is a lot to be said for some of the off-the-shelf home RAID boxes. I haven't researched them, but I know a friend like the Synology NAS boxes. Most of those types of solutions are really Linux systems, but whether it's really software or hardware, I don't know, so I don't know if you could pull the drives and use Linux to recover your data. That should be a standard question to ask vendors before purchasing, but I doubt many people consider it.
Re:Software RAID (Score:5, Informative)
My Synology box (which is indeed a Linux box) has been humming along for over a decade now. Synology uses software RAID. They've implemented their own solution which lets you mix and match different sized disks, and it will intelligently make use of all the extra space (assuming you're using three or more disks). This lets you increase your RAID disks over time, a feature I've taken advantage of over the years as disk sizes have increased, while prices have come down.
I've had a couple of drives fail over that time, and I ordered new, larger drives for replacements. The replacement procedure was easy, as the drives are mounted in front of the box, and are hot-swappable. So pop the old one out, mount and push the new one in, then use the configuration control panel and tell it to rebuild the drive array using the new drive. After x hours of formatting and copying data, the job is done, with zero downtime.
if someone wants a NAS box, I'll always recommend Synology.
Re: (Score:2)
I believe Synology also makes it possible to recover data in case of hardware failure - either using another synology device, or using a special Linux distirbution that can mount all the disks.
Data protection is key - disk failure is the most likely cause of data loss, so RAID helps protect against it. However, you also want to protect against hardware failure - if the RAID hardware fails, how would you recover from that? Motherboard RAID is only recoverable in RAID1 (mirroring) mode - basically stick it in
Re: (Score:2)