What have been peep's experiences with building RAID arrays with 16TB, 20TB, etc. hard drives?

Too big and slow to pivot when a drive breaks? Lower reliability per spindle compared to smaller units? No differences of note?

Context: I have multiple 6 disk draid2 configs with 8TB spindles. The drives are aging out and could use an excuse to reduce the number of spindles (less heat, noise, power, weight). Thinking about 3-4 way raidz[1|2] — or maybe something different.

Opinions and comments appreciated.

#zfs #md #mdraid #mdadm #raid #soho #Infrastructure #cloud #HomeLab #SelfHosted #SelfHosting

My home NAS runs mdraid RAID1 on top of two HDDs, each of which is covered by dm-integrity to guard against silent data corruption. Due to how dm-integrity lays out its data, the read-write performance is about half of what the hardware is capable of. I moved dm-integrity tags onto a separate disk to improve the situation, and bumped into a few problems along the way. More details in my blog: https://blog.tty8.org/posts/2025-04-02-moving-dm-integrity-tags-off-the-hdd-to-speed-up-raid.html

#linux #mdraid #dmintegrity

Am I reading the Linux #mdadm manpage correctly?

AIUI it says that the property of whether a RAID whose component devices are found is auto-assembled is a property of only the mdadm.conf file on the host doing the assembly.

What I need to have is, like on classic BSD RAIDframe, to encode into the superblock of the component devices that the RAID must never be auto-assembled. Is this truly not possible with Linux #mdraid?

(Background: the components are protected with dm-integrity but in split setup, i.e. a separate --data-device, which GRUB is indeed allowed to assemble* in read-only mode, to boot from it. But e.g. a grml.org @grmlproject or a Hetzner rescue system is not allowed to assemble it because otherwise the integrity of the superblock goes kaboom. I know I can boot Grml with the forensic boot option, but…)

*) It’s a RAID 1 for /boot so in theory no assembly even needed for GRUB, no idea what it actually does.

Есть всё-таки что-то прекрасное в профессиональных инструментах, которые просто делают то, что нужно.

я: mdadm, собери мне, пожалуйста, из коробки деградировавший RAID 6 на пять дисков из четырёх дисков.
mdadm: готово, вот твой новенький деградировавший RAID!

#soft #server #RAID #mdraid #Linux #log #thoughts

Влияние MD checking на производительность и методы уменьшения влияния на работоспособность системы

MD (Multiple Device) — это технология в Linux, которая позволяет объединять несколько физических дисков в один логический накопитель с помощью различных схем RAID (Redundant Array of Independent Disks). mdXXX (далее md disk) — это одино из устройств, созданных с использованием этой технологии. Для определения влияния проверки состояния (checking) массива md disk на производительность системы необходимо рассмотреть несколько аспектов.

https://habr.com/ru/articles/831718/

#mdraid #ionice #cgroups #checking

Do md RAID1 arrays do partial recovery nowadays? I just booted a system with one drive not properly connected. After fixing the problem, the array was degraded ("md: kicking non-fresh sdb2 from array!"). After re-adding the device, a rebuild started ... and was finished within 10 minutes or so (for a 1.8TB mirror). A complete rebuild takes maybe two hours?

#Linux #mdraid

Let's play a game, to help some of the newcomers make connections: name subjects and topics that interest you but aren't in your profile, as tags so they are searchable. Then boost this post or repeat its instructions so others know to do the same.

#reprap
#wrenching
#linux
#devuan
#slackware
#lxc
#mdraid
#ratpoison
#lxde
#mate
#screen
#gnu
#eff
#openstack
#arduino
#recycling
#retrocomputing
#woodworking
#electricvehicles
#gardening
#bicycles
#robotarms
#solarpower
#steampower
#homebrew