Synology expansion unit vs 2nd NAS, and raid 5 or not?

[mcbroomf]

I wonder if anyone has experience expanding a Synology NAS (one of the + series) with their expansion units, or decided to add a 2nd NAS (or perhaps a different route?) as capacity filled.

I have a DS1515+, 5 bay, 6TB drives, raid 5 and will probably fill it by the end of the year.  It's my 2nd backup, with primary storage SSDs and HDs inside a Windows desktop and 1st backup JBOD's HDs in an external box.  The NAS is hardwired to my desktop through the router.  Also have an additional backup in the house and an offsite backup.  I've liked having one large volume which is accessible to Windows PCs that run my printers as well as my laptop even if the desktop is off.

I've read suggestions that raid 5 is a not a great option to use, or at least there are better options, and indeed I had bad experience with it in the past (OWC boxes through USB2) but not the same tech as now.  I think raid 10 was recommended, looking at options I wonder about raid 6 as well going forward.

I can add a 5 bay expansion unit to the 1515+, and I could leave it as raid 5 or switch to a different raid, or I could add a 2nd NAS, perhaps an 8 bay.  With both options I'd use much bigger drives (probably 12TB).  I store my files by calendar folders, so if I add a 2nd NAS I'd just leave the 1515+ static after 2019 and put my 2020 and newer files on the new unit.

I should add that I don't stream anything (I don't have a TV or a stream ready hifi).  Also a new NAS would be 10GBe ready which I don't think my 1515+ is.  I don't need it now and I don't have any other 10GBe hardware.  Maybe a nice to have though ...
 
Experience, thoughts or recommendations?

Thanks

Mike

[Jim Kasson]

I have not had good reliability with the consumer-grade Synology boxes. I have had excellent luck -- no failures in maybe 20 box-years -- with the data-center grade boxes. If you're going to expand a consumer-grade Synology box, I'd recommend a separate NAS rather than the expansion chassis, and redundant storage to both boxes. You'll have more failures, but your eggs will be in two baskets. That's if you car using the Synology boxes for redundancy and fault-tolerance. If you're using them for availability, an expansion chassis might make sense.

I don't recommend RAID 5 with modern, high-capacity drives. The chance of a second failure during rebuild is too high. Better to use RAID 6. Configure a couple of hot standby disks, too, so you don't have to go running to the NAS box every time there's a failure.

Jim

[mcbroomf]

Thanks Jim,
Did you have issues with the box hardware croaking, or drives within those boxes more likely to fail?
Good point about using 2 baskets, and as I have 2 extra full backups on site I'm covered, and the TB3 enclosure gives me faster access than I'd get with the NAS.  I generally just pull files from the NAS to one of my printer computers and don't worry if it takes a few minutes to complete.
Looking at Synology now it appears that their XS models are probably their data/enterprise NAS.  More expensive than the Plus series for sure and unfortunately no 8 bay offered so I'd probably have to go up to a 12 bay.  Tons of room for expansion though.

[Jim Kasson]

Thanks Jim,
Did you have issues with the box hardware croaking, or drives within those boxes more likely to fail?

The boxes, but now that you mention it, the drives last longer, too.

jim

[Joe Towner]

This thread should be in the Computers & Peripherals section.

So let's start with the easy questions, and get into the deeper options.  RAID5 is fine, the data set is 'small' in that it's only across 5 drives - I do SHR2 or RAID6 in a 8bay DS1817+.  If you were to migrate to SHR there may be an advantage, but it's limited.  When did you build this NAS and how big was the initial data set you copied from other places?  How many TB's of data did you add in 2018 and is 2019 trending to be more?  Beyond the disk space running out, are there other issues or limitations in the NAS as it sits?

Honestly, doing single drive upgrades from 6tb to 10tb/12tb drives in the current enclosure will most likely get you a couple of years more use without the additional investment of an enclosure or new NAS.  Hard drives don't die like they use to, and since this is a second backup location the idea of having it 'die' isn't as impacting compared to someone who works off their NAS directly.  If you want to 'rebuild' the NAS, turn it off & swap all the disks at once, then recopy everything over from your source jbod disks, it may be faster.  You can always take the removed 6tb disks and attach them to a pc and do a live linux cd to mount the RAID drive to copy off.

-Joe

[mcbroomf]

Hi Joe thanks for your reply, sorry I put this in the wrong section.

I bought the NAS in Jan 2016, started with approx. 10TB TB of data.  Since then; 2016 1.8TB, 2017 2.2TB, 2018 3.4TB, 2019 similar pace to 2018.  I have ~3TB left but obviously don’t want to fill it completely.  No issues so far.

I didn’t realize it when I posted initially but the 1515+ is spec’d at 30TB max (5 x 6TB drives which is what it’s filled with, 22TB available in Raid 5) so unless there’s a firmware update that allows larger drives I’ll have to expand.  I sent Synology an inquiry, waiting to hear.

I asked mods to move this thread to C&P ...

[Joe Towner]

Hey mcbroomf - it's all good, that's what we have mods for

Based on this thread, you should be fine all the way up to 14tb - https://community.synology.com/enu/forum/6/post/123745

One thing I didn't mention is the ability to shift some earlier years off to an external USB3 drive.  As in take 2015 and earlier and shove them onto an external USB3 connected drive (with additional copies on offline drives).  Use the internal RAID5 set for more recent stuff (adjusting your other backups/sync's accordingly. 

I've seen external 10tb's for $200, and on special for a bit less, figure you can shuck them and fill your NAS for ~$1,000. 

What drives are in your JBOD & other storage systems - offline or offsite?  Doing a data shuffle that shows a round of improvements may be worth it.

[mcbroomf]

Ha, good timing, I just got an email back from Synology with a link to their drive compatibility.  The guy who answered said they don't update their spec sheets so I guess when the 1515+ was released 6TB was all they'd tested it with.  Also I had assumed that expanding the 1515+ just expanded the raid 5 I'm using but he specifically cautioned against that.  They recommend building a new raid in an expansion unit.

In fact I think I may leave the 1515+ alone and fill an expansion unit with 12TB drives, raid 6.  That will give me 36TB, good for a few more years and not too expensive (aside from the drives which I'd need either way)... and I can alternate upgrades, ie when the expansion unit is getting a little full remove the 6TB drives in the 1515+ and update to 12TB drives or drives with the best /TB pricepoint.

I'm using a combination of 10 and 12TB drives in my on-board primary storage and 8TB on the TB3 enclosure.  10TB on a different computer and a mix of 1TB through 4TB offsite.

Still a little concerned with Jim's observation about enterprise hardware vs consumer.  I've asked them what they consider enterprise grade.

[degrub]

If you do that, see if you can expand the cache memory in the main unit.

[Joe Towner]

If you're going to pay for the DX expansion, spend the extra $200 and get a full blown unit like the DS1019+.  The Plus series is 'prosumer' with the XS/XS+ being their business series.  The Values series are ok, with the J being the bare bottom. 

https://www.synology.com/en-us/products

[mcbroomf]

If you do that, see if you can expand the cache memory in the main unit.

I took a look at adding more memory.  Not sure I'll bother given the way I'm using the NAS as my 2nd backup, I guess it's always nice to have faster access but I simply don't use the NAS as anything like a "working" drive.  I could also replace a whole drive with an SSD and somehow use it as cache, but the same issue.

Thanks

[mcbroomf]

If you're going to pay for the DX expansion, spend the extra $200 and get a full blown unit like the DS1019+.  The Plus series is 'prosumer' with the XS/XS+ being their business series.  The Values series are ok, with the J being the bare bottom. 

https://www.synology.com/en-us/products

Yes, that was my 1st question, ie expand with a DX513, or add a 2nd NAS.  What's the advantage of adding a new unit?  Mine is a Plus series, 1515+, no longer offered.
 
The only thing I can think of is that the expansion unit is connected to the main NAS with esata cable and if the original unit conks out for some reason with a hardware issue then I loose both until I can get a new NAS box (which would then have to be compatible with the DX513) and reconnect it.  They guy who answered my questions told me that is I lose a drive on the main unit that as long as I have a separate raid on the expansion unit it would be unaffected.  I'm thinking this is a pretty good reason to go for a separate NAS.

[paulster]

The only vaguely compelling reason I can see for using the expansion unit over a separate NAS is if you absolutely need to expand a single drive array beyond the confines of the original box.  Otherwise you have the advantage of splitting your risk of hardware failure between two devices, and you'll have more CPU and network bandwidth available, at the expense of having to maintain two setups.

[mcbroomf]

The only vaguely compelling reason I can see for using the expansion unit over a separate NAS is if you absolutely need to expand a single drive array beyond the confines of the original box.  Otherwise you have the advantage of splitting your risk of hardware failure between two devices, and you'll have more CPU and network bandwidth available, at the expense of having to maintain two setups.

Yes, Synology rep specifically warned against extending the raid onto the expansion unit, ie just create a new raid on the unit.  It's a little more expensive to buy a new NAS vs expansion unit but in the scheme of things considering the need for 6 x 12TB harddrives, a pretty small amount, and as I posted above it would ward against a NAS unit fail where the expansion unit raid would be intact but inaccessible while the main NAS is repaired or replaced.  I have no need to expand the raid, I'm perfectly happy to add a 2nd so I think I'm heading towards the unit Joe recommended and as that fills up I'll switch out the drives in the older NAS for much bigger.

Is there a general rule about what % capacity a raid should be considered "full" before it's added to?  I seem to recall the individual drives should only be filled to 90-95% capacity.  I'm at about 87% at the moment.

[Joe Towner]

I'm running a lot closer to the edge with my 97% on the volume - I'm doing cleanup & organization in the background, but yea, there comes a point when you have to stop.  There are huge advantages with a new NAS - mostly in that you'll not touch it for that much longer.  Doing SHR2 (RAID6, but with extra features) means you lose 2 drives, and doing that in a 5 bay enclosure means you only have the capacity of 3 drives.  Stepping up to a 6/8 bay enclosure means you're getting 4-6 drives of usable space.

My biggest complaint about the current Synology lineup is 4x 1gb ports is bunk in my opinion for 2019 'new products'. Synology doesn't have a combo 10gbps ethernet + 2x SSD caching card like QNAP does, so in their single slot models we have to choose one. I just did up a proposal for a RS3618xs unit for a client & we're filling it with 12x 10TB drives due to the cost per gig.  Doing an 8 bay unit with 10TB drives would get you like 54TB usable. Stepping up to 12TB drives would only gain you 6(ish)TB, or 14TB would gain 12(ish)TB.  IMHO the price jumps don't make up for the minimal gains in capacity.

Just playing with price & options:
DS2419+ $1,500 (12bay)
8TB ext drive (WD/Seagate) 5400rpm (shuck the drive out of the enclosure) $140 each
$3,180 for ~74TB of usable

DS1819+ - $905 (8bay)
10TB drives (shuck'ed) $200 each
10TB NAS drives $270 each (WD RED, 5400rpm)
$2,505 for ~54TB usable space with shucked drives
$3,065 with 'NAS' drives

Performance of the three units above would be about equal - more spindles, on slightly slower drives.  Both setups could take a 10gbps card or a dual SSD cache card.  As for shuck'ing external drives, just make sure the model you're getting has their 'compute' brand disks inside, not the Archival one.  With any of the arrays having a space onsite really makes it easier to deal with any possible failure, but drives don't die like they use to (touch/knock on wood).

[mcbroomf]

I think I'm inclined to go with the DS1618+,  a 6 disk plus unit.  Looks like I could add a 10GBe NIC later on if I want more speed. 

I had not thought about using 10TB drives but a couple of 12TB drives had prices drop in the last couple of days to $330, about the same /TB cost as $270/10TB.  Shucking is interesting but I think I'd prefer to stick with native drives.  I will wait a while and see if prices for 10TB drives drop.

If I use raid 6 I'll get 48TB which is tons, and I can update the 1515+ to 12TB drives or more in a few year when prices drop and I think the 6TB maybe close to EOL.

[paulster]

I like the DS18xx+ series and have a couple of them, although I am about to switch out one to a DS2419+ for greater flexibility.  With 8 slots you have the option to have a couple of arrays in the same unit, which can be useful, or you can keep adding drives to expand an existing array over time.  The 12 slot unit I like because it'll allow me to build a new array alongside an existing one using much bigger disks, migrate the shares over to that array, and then decommission the previous disk set and remove the disks all within the same chassis.  Otherwise I'd have to do a complete RAID rebuild for each disk I swapped out, which adds risk.

I like the either the Mellanox ConnectX-2 single-port 10Gbe cards, or the Mellanox ConnectX-3 dual-port 10Gbe cards in mine, and they've cheap and easy to source.  I wouldn't recommend the ConnectX-2 dual-port since the PCIe bus in the Synology units isn't electrically wide enough to get the full bandwidth available from both ports on this PCIe 2.0 card, although the likelihood is you'll max out the drives before you max out the network interface anyway.

[douglevy]

FWIW - I have the 1815+ and the 5 bay expansion unit, setup to raid 5. I've had zero issues and currently have just shy of 40 TB of data out of 80 capacity. I run 12 drives with 1 hot spare. I have a mix of 8 and 12 tb drives in it, and will phase the 8's out as I need more storage.

-D

[mcbroomf]

I changed my mind from my post above and ordered a DS1819+ but only the 6 x 12TB drives I'd planned on.  I'll run them Raid 6 so get 48TB and will swap out the 6TB drives in my old unit and build a bigger raid when the time comes (quite a few years).  And I can use the 2 spare slots as needed over time to expand.

Thanks everyone for your advice and discussion ...

[andyptak]

Joe, could you expand on the "make sure the model you're getting has their 'compute' brand disks inside, not the Archival one" comment please?

I'm going through a similar exercise myself, although with different products and am wondering about drive choice. I'm looking to end up with 30-40 TB of decent drives that don't cost an arm and a leg. Thanks.