Re: To partition or not to partition MD arrays (Was Re: smartctl cannot access my storage, need syntax help)
Hey Andy. Andy Smith wrote: > >On Thu, Jan 18, 2024 at 12:53:43AM +, Steve McIntyre wrote: >> I'm clearly a member of a third group of people,,, :-) > >Oh, I didn't mean to imply that those going by taste were in a >minority! Taste, or possibly, "just never thought about it" could >well be the biggest group. I was only talking about my observations >of those who seem to hold strong opinions on this, usually to the >point where they will advocate "their way" to others. ACK! >> Putting partitions on the RAID drives helps *me* identify them. > >So, I don't care what people do and I'm not trying to change your >mind. Would you mind going into what makes "sda1" more identifiable >for you than "sda" though? > >Or is it that you make use of partition labels for some extra info? If I'm looking at disks on a system, the first thing I'll look for is the partition table. If a disk has a partition table with "Linux RAID" partitions viaible, that gives me a strong hint of what I should expect on the disk. Especially if I'm swappings disk around between systems, commisioning new systems and re-using disks etc. -- Steve McIntyre, Cambridge, UK.st...@einval.com Can't keep my eyes from the circling sky, Tongue-tied & twisted, Just an earth-bound misfit, I...
Re: To partition or not to partition MD arrays (Was Re: smartctl cannot access my storage, need syntax help)
Hello, On Thu, Jan 18, 2024 at 12:53:43AM +, Steve McIntyre wrote: > I'm clearly a member of a third group of people,,, :-) Oh, I didn't mean to imply that those going by taste were in a minority! Taste, or possibly, "just never thought about it" could well be the biggest group. I was only talking about my observations of those who seem to hold strong opinions on this, usually to the point where they will advocate "their way" to others. > Putting partitions on the RAID drives helps *me* identify them. So, I don't care what people do and I'm not trying to change your mind. Would you mind going into what makes "sda1" more identifiable for you than "sda" though? Or is it that you make use of partition labels for some extra info? Thanks, Andy -- https://bitfolk.com/ -- No-nonsense VPS hosting
Re: To partition or not to partition MD arrays (Was Re: smartctl cannot access my storage, need syntax help)
Andy Smith wrote: > >The newer set of people recommending partitions are mostly doing so >because there's been a few incidents of "helpful" PC motherboards >detecting on boot what they think is a corrupt GPT, and replacing it >with a blank one, damaging the RAID. This is a real thing that has >happened to more than one person; it even got linked on Hacker News >I believe. > >Then there will just be people going by taste. > >Personally I still put them directly on drives. If I ever get taken >out by one of those crappy motherboards, I reserve the right to get >a different religion. ð I'm clearly a member of a third group of people,,, :-) Putting partitions on the RAID drives helps *me* identify them. -- Steve McIntyre, Cambridge, UK.st...@einval.com Can't keep my eyes from the circling sky, Tongue-tied & twisted, Just an earth-bound misfit, I...
To partition or not to partition MD arrays (Was Re: smartctl cannot access my storage, need syntax help)
Hello, On Tue, Jan 16, 2024 at 01:01:02PM -0800, David Christensen wrote: > On 1/16/24 11:51, Franco Martelli wrote: > > I thought it was mandatory for a RAID to partition drives with this > > partition type, am I wrong? In the ancient past it was required, because that was one of the ways that mdadm arrays were assembled: the md kernel driver saw the "LInux RAID" partition types and tried using them. If you weren't going to do that, you had to have an mdadm config file, or ewven specify the topology on the kernel command line. This was 15 or more years ago. Ever since udev, each newly-appearing block device is handed to a script for incremental assembly based on the md metadata on the device itself, so any kind of block device will do. > As I switched from mdadm(8) to zfs(8) years ago, perhaps another > reader can explain what mdadm(8) does when given whole disks and > when given disk partitions. mdadm doesn't care. The older set of people recommending partitions were because drive capacities used to vary quite a lot more than they do today. So people used to say, "put a partition on and make it few hundred MB less than the total size of the drive, then if you have to replace it with a slightly smaller one you'll be fine." Since 2005 or so there has been a standard called IDEMA LBA1-03¹ about what the actual capacity in sectors should be for any stated drive capacity, and most drives obey this, though there are still a few exceptions. So this is very much less of a concern, especially for those buying "enterprise" storage. The newer set of people recommending partitions are mostly doing so because there's been a few incidents of "helpful" PC motherboards detecting on boot what they think is a corrupt GPT, and replacing it with a blank one, damaging the RAID. This is a real thing that has happened to more than one person; it even got linked on Hacker News I believe. Then there will just be people going by taste. Personally I still put them directly on drives. If I ever get taken out by one of those crappy motherboards, I reserve the right to get a different religion. 😀 Thanks, Andy ¹ https://idema.org/wp-content/downloads/2169.pdf -- https://bitfolk.com/ -- No-nonsense VPS hosting
