Recommended RAID Controllers

Issues related to hardware problems
kbocek
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Recommended RAID Controllers

Post by kbocek » 2019/08/12 15:53:59

Preparing to build a new server when Centos 8 is released. What are recommendations for RAID controllers?

I loved my old 3Ware controllers (especially the web interface) but those are long gone. The last host I built I used an LSI Megaraid. I see those on Amazon. Less happy with having to use the stand-alone windows software to manage it, but it's working.

Anyone using anything else in terms of hardware RAID?

kbocek
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Re: Recommended RAID Controllers

Post by kbocek » 2019/08/21 17:31:35

Wow, nothing? I know RAID hasn't fallen out of "fashion."

aks
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Re: Recommended RAID Controllers

Post by aks » 2019/08/21 18:43:15

Yeah, scale horizontally for both performance and HA. RAID used to be Redundant Array Of INEXPENSIVE Disks, until a bunch of vendors figured they could make a bucket load of money from it. The things like I/O quiesce and stripping are not that hard, but many (larger) vendors pretended it was.
Welcome to the big pile of sh*t (TM) called micro services. Well it's not true, you can get redundancy without RAID even in monolithic services (just think "outside the box" - man I should be a management consultant).
It depends on your persistence layer. What do you need to store? How much and how often? What happens if you loose it? For example most RDMS now offer ways to replicating data around, and yes you need to think about your particular use case, but it has been battle tested. Even in the "NoSQL" camp, you can have redundancy.
I blame $$$$$$$ :D

kbocek
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Re: Recommended RAID Controllers

Post by kbocek » 2019/08/21 20:22:22

I just want to be able to replace a failed drive seamlessly. Like I've done dozens of times over the years.

I guess the LSI Logic cards are the only game in town. It really bugs me that the software out there (megaraid) hasn't been updated in *years*.

aks
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Re: Recommended RAID Controllers

Post by aks » 2019/08/24 10:45:46

Why not use software RAID?

kbocek
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Re: Recommended RAID Controllers

Post by kbocek » 2019/09/02 18:34:19

Because hardware RAID offer so many features: a management interface *outside* of the OS, hot swap and automatic rebuild, automatic integrity checking, performance since these functions are done by the controller.

aks
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Re: Recommended RAID Controllers

Post by aks » 2019/09/05 17:14:53

a management interface *outside* of the OS,
Yup but without the OS, it ain't doing it's thing.
hot swap and automatic rebuild
Hot swap can be done in software. If you have hot swap hardware then that too can handled by software.
Automatic rebuild, okay, maybe the specific hardware can recover from a very specific case, but software can do this too.
In a truly disastrous scenario (think petabytes of trash), I've never had a non intervening (i.e.: human involved) recovery - no matter how much money was thrown at the problem (although I suspect billions would solve it).
automatic integrity checking
Not really in the general case. Sure RAID scrubbing (which software does anyway) can help. But the meaning of blocks on are disk are lost to the disk/array.
performance since these functions are done by the controller.
Really? Have you looked at <insert modern system name> can do? Usually the "speed" case is more hardware, not calculating RAID values. This was true (say) 10 years ago, bit not now.

Plus software gives you flexibility.

Well if you want to throw lots of money at it, that's your thing.

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TrevorH
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Re: Recommended RAID Controllers

Post by TrevorH » 2019/09/05 17:19:19

Given the choice of hardware or software RAID I would always choose hardware. It's just easier and quicker and better.
The future appears to be RHEL or Debian. I think I'm going Debian.
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
Use the FAQ Luke

kbocek
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Re: Recommended RAID Controllers

Post by kbocek » 2019/09/05 18:22:46

Yeah, what Trevor said.

northpoint
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Re: Recommended RAID Controllers

Post by northpoint » 2019/09/05 18:48:25

I run both Hardware raid and software raids. They both have their advantages and disadvantages though. The only bad side of a hardware raid controller is that if it dies you best have another one ready. If in an enterprise environment I would stock a replacement. Also the cache batteries too. Depending on the manufacturer (ahem, Dell) you probably would have to keep in mind the firmware versions too.

Software raid I do not have to worry about that situations above. Not that software raid is better its just in a failure situation you stand to be up and running quicker with software raid. I also find software raid more feature rich depending again on the hardware raid controller you choose.

Price comes into play here too. However, To each their own.
Ryzen x1800 * Asus x370 Pro * CentOS 7.4 64bit / Icewarp /

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