NAS - Upgrading from 1 HDD to Multiple HDD and RAID?

[gryffinwings]

So I'm not sure how to search for what I'm asking for information about, but I think the title says it all.

Say you have a NAS, and at one time, you were only able to afford a single HDD and it was enough, say you were able to upgrade to have an additional 3 HDD and can now setup a RAID 5 or 10. Is there a way to maintain your files on the drive they are on or do they need to be backed up to another storage device? Also how does adding additional drives to a RAID array work?

Thanks for information or link? I know the basics about RAID and the basics, but have never implemented it.

 

[Charlie22911]

Drobo does this, you can add drives at a later date to increase capacity.
If you want to roll your own, unRAID is very similar.

In both cases a drive is dedicated to parity, adding a drive will cause a parity rebuild and you’ll gain more capacity without losing data.
Traditional RAID is not capable of this.

 

[mxnerd]

QNAP / Synology / ASUStor also support RAID level migration.

https://www.qnap.com/en/how-to/tutorial/article/online-raid-level-migration/

https://www.synology.com/en-us/know.../StorageManager/storage_pool_change_raid_type

https://www.asustor.com/online/College_topic?topic=352#11

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Dell PERC RAID controllers support RAID level migration too.

https://www.dell.com/support/articl...troller-perc-h310-h710-h710p-and-h810?lang=en

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INTEL Rapid Storage Technology Raid Level Migration

https://www.intel.com/content/www/us/en/support/articles/000005997/technologies.html

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RAID migration is slow and risky though. You better hope there won't be power outage in the following days.

 

[gryffinwings]

So is when converting from a single drive to RAID, you are doing a RAID Migration?

Is RAID migration hardware supported only or is it supported through whatever underlying software or OS you would be using?

 

[mxnerd]

So is when converting from a single drive to RAID, you are doing a RAID Migration?
Is RAID migration hardware supported only or is it supported through whatever underlying software or OS you would be using?

1. Yes.

2.

• DELL's PERC controller RAID is hardware based.
• QNAP/Synology/Asustor : hardware/software combination. <-- should be software based according @dave_the_nerd and Synology website.
• Intel Rapid Storage Technology is pure software based. Very unreliable (according to my own experience and internet) Usually being called FakeRAID. https://mangolassi.it/topic/6068/what-is-fakeraid/3

Someone correct me if I'm wrong.

 

[dave_the_nerd]

QNAP/Synology/Asustor is a hardware/software combination.
...
Someone correct me if I'm wrong.

On the high end units, maybe? But on the low end 2-4 bay units, I'm pretty sure those boxes just use SoCs with plain-vanilla SATA controllers, embedded Linux, and mdadm (with a few proprietary tweaks, presumably) software RAID.

At least as of 2014. Dunno what they're doing now, but I doubt they added hardware RAID.

 

[mxnerd]

OK. Here is a list of the chips (CPUs) Synology use for their NAS. Seems no hardware controller though.

Many model use SoC CPUs like @dave_the_nerd has suggested.

https://www.synology.com/en-us/knowledgebase/DSM/tutorial/General/What_kind_of_CPU_does_my_NAS_have

 

[thecoolnessrune]

DELL's PERC controller RAID is hardware based..

I'll also note that Dell has an "S" line of PERC Controllers just like Cisco and HPE does. All variants are simply Software RAID Engines extending the functionality of the Intel PCH RAID (basically using the straight-through drive functionality of the Intel PCH to overlay their own gated, proprietary software RAID engine on top of it). Some, like Cisco's, are even compatible with Broadcom's centralized Storage deployment / management / monitoring software. But those entry-level "controllers" are still just software raid at the end of the day.