Hetzner: AX series - is RAID 1 mandatory?

seenu · November 2020

Hello,

I am trying to get AX 41 from hetz but i see that they mentioned 'raid 1' in details page

and for me, using NVMe disk for backup looks funny

my doubt is.... is raid 1 mandatory there or they are just showing it for info purpose?

thanks

RouteIX · November 2020

No,

If you use their rescue system, and follow the prompts there, you can select your own level RAID, or pull it out of RAID entirely.

Just takes a few more steps, and you'll be storted.

seenu · November 2020

Thanks @RouteIX

mezoology · November 2020

maybe you know this but ill just include it as of maybe you missed it. and assuming you need it for backup

@seenu said: using NVMe disk for backup looks funny

you can click in 'storage' instead of 'high i/o' on the top of the page.
it will convert the 2x 512G NVMe drives to 2x 2TP HDDs.

Mulder · November 2020

@seenu said: and for me, using NVMe disk for backup looks funny

are you going to use AMD Ryzen 5 3600 for backup? that's crazy

seenu · November 2020

@Mulder Nope, that's why I am asking a way to get rid of RAID 1 and use external backup solution

chocolateshirt · November 2020

Raid is not for backup, it is for redundancy/performance.

Mulder · November 2020

@seenu said: Nope, that's why I am asking a way to get rid of RAID 1 and use external backup solution

take the NVMe in raid1 and upgrade https://www.hetzner.com/additional-hardware/ for backups

seenu · November 2020

@chocolateshirt said: Raid is not for backup, it is for redundancy/performance.

Honestly I am very new to word raid but from whatever i read online, RAID 1 makes copy of primary disk so can't we call it backup?

AC_Fan · November 2020

@seenu said:

@chocolateshirt said: Raid is not for backup, it is for redundancy/performance.

Honestly I am very new to word raid but from whatever i read online, RAID 1 makes copy of primary disk so can't we call it backup?

No, for many reasons:
It's in the same physical location and storage medium.
Software errors and human ignorance will cause data loss.
Etc.

RAID is just for keeping stuff online, backups must always be done.

seenu · November 2020

Oh, i wil learn more about it.

seenu · November 2020

@AC_Fan overall do you recommend, keeping it RAID 1 or no raid is also fine?

saibal · November 2020

RAID 1 should improve read speeds with the proper drivers.

Falzo · November 2020

@saibal said:
RAID 1 should improve read speeds with the proper drivers.

and saves your ass in case one drives suddenly dies.

@AC_Fan pointed out, that is still a big difference to a proper backup though. you delete something on your raid 1 - it's gone, malware messes your data - your f*cked. your provider deadpools ... I think you get the idea, why raid-1 is not a backup but a redundancy to protect against SPOF.

Not_Oles · November 2020

@seenu

Hello from Mexico!

I think it's really great that you are going to get your own server. I wish you the very best as you start on your very fun server journey!

Maybe it might be helpful to you if we think about two different high level functions:

The first function, backup, might be the ability to restore data if the data on the main machine is lost -- because a disk drive fails, because the datacenter building burns down, whatever.

The second function, redundancy might be the ability of a machine to continue running despite failure of a key hardware component such as disk drive, power supply, network connection, etc.

It might be fair to say that RAID is trying to address the second function (redundancy) but indirectly and partially addresses the first function (backup).

What happens is that RAID "wastes" disk space by mirroring or striping multiple copies of the data on multiple disks. The result is that, when one disk goes down, the machine can continue to function because it still can access everything despite that one disk is gone. Maybe the dead disk can be hot swapped without even rebooting the machine. Once a new, working disk is present, RAID will copy everything to the new disk and return to having multiple copies of all the data.

So maybe we can say that RAID provides a backup in the sense of redundancy but not in the "real" backup sense which permits data to be restored from remote backup which is completely isolated from the original machine's datacenter.

An important factor in choosing whether "To RAID or not to RAID" (Hamlet) is how often your data changes. One guy doing programming might be quite happy with not using RAID and making a once a day, offsite backup. A bank, with many customers and thousands of transactions a second will want more than just one backup per day. Everybody falls somewhere along this continuum. Hetzner will let you set up your server with or without RAID, as you prefer.

I know from previous discussions that you are interested in using Proxmox. You might want to check out this page on software RAID with Proxmox: https://pve.proxmox.com/wiki/Software_RAID

Besides RAID, another factor to consider when selecting a server is "To ECC or not to ECC." AX41 comes with non-ECC memory. ECC is an upgrade. Here are links to a HN discussion of a page about ECC which I found helpful: https://news.ycombinator.com/item?id=25167288 and https://danluu.com/why-ecc/

There are different types of RAID and different types of ECC memory. I went with software RAID 1 and Proxmox on an AX51 server which has ECC as the default. So far, it works great!

Folks here on LES who understand much more than I do: please correct the mistakes I made while trying to help @seenu .

I hope this is helpful! Good luck with your new server!

akhfa · November 2020

@Not_Oles said:
@seenu

Hello from Mexico!

I think it's really great that you are going to get your own server. I wish you the very best as you start on your very fun server journey!

Maybe it might be helpful to you if we think about two different high level functions:

The first function, backup, might be the ability to restore data if the data on the main machine is lost -- because a disk drive fails, because the datacenter building burns down, whatever.

The second function, redundancy might be the ability of a machine to continue running despite failure of a key hardware component such as disk drive, power supply, network connection, etc.

It might be fair to say that RAID is trying to address the second function (redundancy) but indirectly and partially addresses the first function (backup).

What happens is that RAID "wastes" disk space by mirroring or striping multiple copies of the data on multiple disks. The result is that, when one disk goes down, the machine can continue to function because it still can access everything despite that one disk is gone. Maybe the dead disk can be hot swapped without even rebooting the machine. Once a new, working disk is present, RAID will copy everything to the new disk and return to having multiple copies of all the data.

So maybe we can say that RAID provides a backup in the sense of redundancy but not in the "real" backup sense which permits data to be restored from remote backup which is completely isolated from the original machine's datacenter.

An important factor in choosing whether "To RAID or not to RAID" (Hamlet) is how often your data changes. One guy doing programming might be quite happy with not using RAID and making a once a day, offsite backup. A bank, with many customers and thousands of transactions a second will want more than just one backup per day. Everybody falls somewhere along this continuum. Hetzner will let you set up your server with or without RAID, as you prefer.

I know from previous discussions that you are interested in using Proxmox. You might want to check out this page on software RAID with Proxmox: https://pve.proxmox.com/wiki/Software_RAID

Besides RAID, another factor to consider when selecting a server is "To ECC or not to ECC." AX41 comes with non-ECC memory. ECC is an upgrade. Here are links to a HN discussion of a page about ECC which I found helpful: https://news.ycombinator.com/item?id=25167288 and https://danluu.com/why-ecc/

There are different types of RAID and different types of ECC memory. I went with software RAID 1 and Proxmox on an AX51 server which has ECC as the default. So far, it works great!

Folks here on LES who understand much more than I do: please correct the mistakes I made while trying to help @seenu .

I hope this is helpful! Good luck with your new server!

Just want to say, nice explanation here

seenu · November 2020

Thanks for great explanation and for taking your time to write such lengthy one @Not_Oles
Highly appreciated

yokowasis · November 2020

@Not_Oles said:
@seenu

Hello from Mexico!

I think it's really great that you are going to get your own server. I wish you the very best as you start on your very fun server journey!

Maybe it might be helpful to you if we think about two different high level functions:

The first function, backup, might be the ability to restore data if the data on the main machine is lost -- because a disk drive fails, because the datacenter building burns down, whatever.

The second function, redundancy might be the ability of a machine to continue running despite failure of a key hardware component such as disk drive, power supply, network connection, etc.

It might be fair to say that RAID is trying to address the second function (redundancy) but indirectly and partially addresses the first function (backup).

What happens is that RAID "wastes" disk space by mirroring or striping multiple copies of the data on multiple disks. The result is that, when one disk goes down, the machine can continue to function because it still can access everything despite that one disk is gone. Maybe the dead disk can be hot swapped without even rebooting the machine. Once a new, working disk is present, RAID will copy everything to the new disk and return to having multiple copies of all the data.

So maybe we can say that RAID provides a backup in the sense of redundancy but not in the "real" backup sense which permits data to be restored from remote backup which is completely isolated from the original machine's datacenter.

An important factor in choosing whether "To RAID or not to RAID" (Hamlet) is how often your data changes. One guy doing programming might be quite happy with not using RAID and making a once a day, offsite backup. A bank, with many customers and thousands of transactions a second will want more than just one backup per day. Everybody falls somewhere along this continuum. Hetzner will let you set up your server with or without RAID, as you prefer.

I know from previous discussions that you are interested in using Proxmox. You might want to check out this page on software RAID with Proxmox: https://pve.proxmox.com/wiki/Software_RAID

Besides RAID, another factor to consider when selecting a server is "To ECC or not to ECC." AX41 comes with non-ECC memory. ECC is an upgrade. Here are links to a HN discussion of a page about ECC which I found helpful: https://news.ycombinator.com/item?id=25167288 and https://danluu.com/why-ecc/

There are different types of RAID and different types of ECC memory. I went with software RAID 1 and Proxmox on an AX51 server which has ECC as the default. So far, it works great!

Folks here on LES who understand much more than I do: please correct the mistakes I made while trying to help @seenu .

I hope this is helpful! Good luck with your new server!

Yes, yes, i see. hmmm.. Good. Perfection.

Hetzner: AX series - is RAID 1 mandatory?

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