Is there NAS software/hardware that allows different size drives?

[OMK]

I currently have a Drobo 5N.  Since the company closed down last year, I want to either purchase a new NAS storage solution or build my own to have a back up or before this one stops working. 

 

For me, the best thing about the Drobo is the fact that I can have drives of different sizes.  I (think I) started with three 6TB drives, then added an 8TB drive as an example.  I now have a 1x10TB WD Red, 2x8TB Seagate IronWolf and 2x6TB Seagate IronWolf drives. Every time I ran out of space (or there was a really good sale on) I just took out the smallest drive and replaced it with a larger one.  This is so much better than having to spend 189,820 JPY (1,758 CAD) all at once to get four 10TB drives.  It also has a type of RAID 5 that allows for just swapping drives. It automatically rebuilds the array, allocating the files and uses ALL of the drive space.  This feature also means if one drive fails, you still have all your data.

 

Does anyone know if there is a software/hardware solution that will allow me to have this same type of flexibility?  I would prefer to use one of my old computers to build this so I can upgrade in the future, like to 2.5/5 Gbps networking or adding more memory.  If it's not possible then some sort of NAS box with the flexible HD features would have to do.  Or even a RAID card of some sort if it comes to that.

 

I have tried to search for this but I haven't really found a good answer which is why I am here.  If my search skills suck and there is an article somewhere that clearly answers my question, then just posting a link would be fine.

[Robchil]

synology?.. it has it's own "raid" where you can add drives. 

 

[ChrisLoudon]

23 minutes ago, OMK said:

have tried to search for this but I haven't really found a good answer which is why I am here

Hi buddy,

 

I use Unraid for different sized disks.

 

Its not free but the max you'll pay is about $89 for a lifetime license.

 

My NAS has an 8TB + 6TB for double parity (allows for 2 drive failures). The main storage array then has 4TB + 4TB + 4TB + 4TB + 2TB + 1TB totalling 19TB of storage. And then to speed things up I have a 4TB SSD for cache.

 

The only stipulation with Unraid with regards to drive sizes is that the Parity drive(s) need to be the same size or larger than that largest disk in the storage pool.

 

Also, Unraid is installed and boots from a USB stick and runs entirely from RAM so you don't need a boot disk

[OMK]

2 hours ago, Robchil said:

synology?.. it has it's own "raid" where you can add drives. 

 

Thank you for this. 

 

I looked at the Synology website.  They have a raid calculator.  I used it to look at RAID 5.  It seems to only be using the smallest drive size.  If you have 5x8TB drives it calculates 29.1 TB of usable storage (the rest is for parity).  If you upgrade and add 1x6 TB drive it makes the 8 TB drives smaller so you now only have 27.3 TB of storage.  That's 2 TB LESS after adding 6 TB.

 

This is, unfortunately not what I am looking for.

 

 

[OMK]

2 hours ago, ChrisLoudon said:

The only stipulation with Unraid with regards to drive sizes is that the Parity drive(s) need to be the same size or larger than that largest disk in the storage pool.

Thank you.

 

I'm not sure I completely understand what this means, but it does give me a jumping off point to do more research which is really helpful.  Thankfully I will have some time tomorrow during work to do a bit of reading.

[Needfuldoer]

23 minutes ago, OMK said:

Thank you for this. 

 

I looked at the Synology website.  They have a raid calculator.  I used it to look at RAID 5.  It seems to only be using the smallest drive size.  If you have 5x8TB drives it calculates 29.1 TB of usable storage (the rest is for parity).  If you upgrade and add 1x6 TB drive it makes the 8 TB drives smaller so you now only have 27.3 TB of storage.  That's 2 TB LESS after adding 6 TB.

 

This is, unfortunately not what I am looking for.

 

 

Try "SHR", Synology Hybrid RAID. That should let you mix and match drives without wasting too much space. (I believe it dedicates the largest drive as parity space, like Unraid does.)

[OMK]

29 minutes ago, OMK said:

I'm not sure I completely understand what this means

Curiosity got the better of me and instead of going to sleep I looked this up.  Now I understand.

[brwainer]

Unraid or SHR as mentioned above… one difference is that SHR works more like Drobo’s implementation, meaning you will get more than one drive’s speed most of the time, whereas Unraid will never be faster than a single disk at a time other than SSD caching.

[ChrisLoudon]

14 hours ago, brwainer said:

one difference is that SHR works more like Drobo’s implementation, meaning you will get more than one drive’s speed most of the time

Yeh, Unraid can be pretty slow with writes but the cache helps. A fast SSD does the trick though.

 

An unrelated but still on-topic question though. Is data in a RAID5/6 array still accessible even with a failed drive(s)? As far as I understand, when a RAID 5 or 5 array is degraded, the data is still accessible in read only form as the data can be retrieved on-the-fly using the parity information. Full speed read / write ability returns when the drive is replaced and the array rebuilt.

 

On the other hand, In an UNRAID array, when a drive fails, the data ISN'T recoverable until the drive is replaced. When in a degraded state, only the data on that drive isn't accessible until replaced.

[Needfuldoer]

4 hours ago, ChrisLoudon said:

Is data in a RAID5/6 array still accessible even with a failed drive(s)?

Yes, so long as you don't lose more drives than you have parity for your pool will keep on trucking along. That's RAID's raison d'être: uptime insurance. (Not as a backup!) 

 

When you replace the failed drive, the RAID controller will use the parity data spread across the other drives to fill in the missing data that belongs on the new, blank drive. It might be a little slower in the meantime, but it shouldn't fail to a read-only state unless you configure it to do so.

[OMK]

5 hours ago, ChrisLoudon said:

Yeh, Unraid can be pretty slow with writes but the cache helps. A fast SSD does the trick though.

 

I'm not 100% sure, but with a NAS, even with a 2.5 Gb Ethernet connection, wouldn't that be the limiting factor with data transfer rates, not the HD?

 

Also, thank you everyone for you help!  It has enabled me to figure out what to look for in my searches.

[brwainer]

2 hours ago, OMK said:

I'm not 100% sure, but with a NAS, even with a 2.5 Gb Ethernet connection, wouldn't that be the limiting factor with data transfer rates, not the HD?

 

Also, thank you everyone for you help!  It has enabled me to figure out what to look for in my searches.

Entirely depends on what you’re doing. Large files that are sequentially written and read? Yeah a single drive is going to sustain >1Gbps all day (right around 2.5Gbps at the outside of the disk where the linear velocity is fastest, slowing down to the middle). More small files (<1MB), or things read non-sequentially, like programs or video editing? Not a chance without a large array or SSDs.

[ChrisLoudon]

19 hours ago, OMK said:

I'm not 100% sure, but with a NAS, even with a 2.5 Gb Ethernet connection, wouldn't that be the limiting factor with data transfer rates, not the HD?

 

Also, thank you everyone for you help!  It has enabled me to figure out what to look for in my searches.

With spinning metal HDDs, even a fast one that could maybe do 200MBs would be faster than a 1Gbs network that tops out at about 100MBs. So yes, theoretically.

 

The problem is, as soon as you mix Parity into the equation, either in a RAID 5/6 array or an UNRAID config, write speeds take a big dip since parity data needs to be calculated ad written (along side the actual data) which is why the cache disk in Unraid is handy.

 

All Data gets written to that 1st then flushed to the array either on command or scheduled.

 

 

[LIGISTX]

15 hours ago, ChrisLoudon said:

With spinning metal HDDs, even a fast one that could maybe do 200MBs would be faster than a 1Gbs network that tops out at about 100MBs. So yes, theoretically.

 

The problem is, as soon as you mix Parity into the equation, either in a RAID 5/6 array or an UNRAID config, write speeds take a big dip since parity data needs to be calculated ad written (along side the actual data) which is why the cache disk in Unraid is handy.

 

All Data gets written to that 1st then flushed to the array either on command or scheduled.

 

 

FWIW, I can write to the Z2 array in my sig at about 4.5-5.5 gbps, which is about the same speed I can read data off it assuming the data is not in ARC. So ZFS parity calculations don’t add that much overhead…. The difference with unraid is, unraid only reads and writes data from/to a single disc, so you don’t get the benefit of reading and writing across many drives at once to increase overall bandwidth. 

[Mihle]

I thought that unraid can read from HDDs faster than one disk, but only if you happen to read files that are on different disks, but you don't have super much control over what files are on what disks. A single file is only read from one disk.

 

I am not wrong am I?

 

I don't know about the other solution mentioned, but I think it's quite easy to add drives later on unraid.

[LIGISTX]

9 hours ago, Mihle said:

I thought that unraid can read from HDDs faster than one disk, but only if you happen to read files that are on different disks, but you don't have super much control over what files are on what disks. Q single file is only read from one disk.

 

I am not wrong am I?

 

I don't know about the other solution mentioned, but I think it's quite easy to add drives later on unraid.

Unraid writes data to a single disc only, it is not set up like a true RAID solution would be… which is why it’s called “unraid”. 
 

https://docs.unraid.net/unraid-os/manual/what-is-unraid/#:~:text=Unlike most RAID systems%2C Unraid,level folder on a drive.

[Mihle]

2 hours ago, LIGISTX said:

Unraid writes data to a single disc only, it is not set up like a true RAID solution would be… which is why it’s called “unraid”. 
 

https://docs.unraid.net/unraid-os/manual/what-is-unraid/#:~:text=Unlike most RAID systems%2C Unraid,level folder on a drive.

I know that, that and I said so in the text you quoted? Doesn't change anything I said?

 

I was talking about reading data, from multiple files, that are on different disks.