eh? It's just extending the internal storage... externally, hence "DAS". It has tons of use cases.
It does, but they MD1000s were mainly setup for SAN devices in mind. Yeah they can also be attached to servers as well which is not bad either. Just not my preference, nothing wrong with that.
Not sure what you mean, a DAS is a DAS... MD1000, MD3000, MD1200, MD1400... whatever. They are simply (as what Dell calls them, @scottalanmiller , not me) "Server JBOD Expansions". They aren't specific to SAN use and are not SANs.
From Scott's post it seemed to say the data written to the drives that allows rebuilding the array when the RAID is replaced is what is missing. If that data is gone, aren't you hosed? Unless it is backed up somewhere?
It's not the disks that are bad, it's the controller itself. It's ROM is messed up.
With luck the flashed controller will pull the array data back in.
My money is on fake RAID you got there. So use md.
Also because you already use MD. 🙂
You know what, I can even move the two disks to my new workstation and not have to transfer any data.
I think the answer may have been found... 😄
Actually even better, I can break the RAID 1 on my current box and convert it to non-RAID, then move one of the disks to my new workstation and convert it back to RAID 1. If done right, I think I can do it all without any data loss too.
I'd prefer to just move the two disks and not have to transfer any data... but that's just me.
Yeah. I'll need to copy my home directory to the SSD in my current box before doing that though. That might be easier than breaking/re-creating the RAID. I'm not quite ready to "switch" yet. Hmm...
One of the confusing pieces here is that Linux actually does things more clearly but the Windows world is so confusing that if you carry that confusion into the Linux world, it makes things harder. Windows rarely uses or discloses the names of their product components. So Windows Software RAID is used to describe part of the Windows OS. But what if you have software RAID on Windows that is not Windows Software RAID? Windows Admins typically have no good terminology to discuss this, even though it is common. They just.... don't know what's going on and don't document it. But in Linux, we have the terms on hand all of the time (MD, ZFS, whatever.) So the Linux side isn't as bad as it seems, but if you are used to a weird blend of generic names being used as if they are specifics from the Windows world and assume that the Linux world is just as crazy, then it seems crazy.
Thanks - I will proceed without using ZFS - I prefer hardware RAID.
ZFS is perfectly fine with hardware RAID, if you like ZFS' features otherwise (like zsend is nice) then there's no reason to avoid it. If you don't plan to use any unique features, then XFS is my "go to" choice by default. Very fast, very stable.
The most common RAIN approach that I see is taking all disks in the pool, noting their nodal presence and using mirroring to distribute the data so that data mirrors never go to the same disk and/or the same node. So a little like a networked RAID 1E but with more flexibility and the option to add nodal separation and performance testing so that data moves to where it is used.
Are you aware of any open source RAIN systems?
Gluster and Swift
I think Ceph and Lustre may be two others.
Lustre is RAIN, but is closed. Gluster was the open replacement for Lustre.
Just a quick search showed that Lustre was GPL 2.0, not sure if that is new or not.
Oh wow, must be new. It was crazy expensive in 2006 when we were really investigating it. That's awesome.
Ah looks like it went open source in 2010.
Oh cool, so I remember things well then. I'm just out of date. Gluster probably forced their hand, why would anyone consider Lustre when it was closed source? The answer was probably... they wouldn't and didn't.
Yep, I'd assume that was the case. Especially when it is a such a specific, and at the time, niche market.
And when Gluster went directly after them, even in name.
Now which applies to MDADM RAID? If Cold swapping is the only way of swapping drives, then I guess it immediately excludes it from any Enterprise or even business solution.
MD RAID (MDADM is the management utility for MD RAID) is hot swap, of course, and some vendors like ReadyNAS and Synology add their own extensions to add blind swapping. No one would even discuss it if it wasn't hot swap.