[Brad]

Nice!

Whether or not I end up with a Synology, I definitely need to upgrade whatever hardware I have powering my NAS before long.

[Brad]

To follow your example, here's what shoving zeroes into a file on my two mirrored 14TB drives in an unencrypted dataset looks like:

# sync; dd if=/dev/zero of=tempfile bs=1M count=1024; sync1024+0 records in1024+0 records out1073741824 bytes (1.1 GB, 1.0 GiB) copied, 0.687322 s, 1.6 GB/s

versus the encrypted dataset

# sync; dd if=/dev/zero of=tempfile bs=1M count=1024; sync1024+0 records in1024+0 records out1073741824 bytes (1.1 GB, 1.0 GiB) copied, 0.687974 s, 1.6 GB/s

Hmm. Methinks ZFS being clever with zeros. I also have LZ4 compression enabled, and maybe it's crunching them all down before they hit the disk.

Let's try from random to the unencrypted dataset…

# sync; dd if=/dev/random of=tempfile bs=1M count=1024; sync1024+0 records in1024+0 records out1073741824 bytes (1.1 GB, 1.0 GiB) copied, 4.14828 s, 259 MB/s

Ahh, that looks more realistic. And to the encrypted dataset…

# sync; dd if=/dev/random of=tempfile bs=1M count=1024; sync1024+0 records in1024+0 records out1073741824 bytes (1.1 GB, 1.0 GiB) copied, 4.62426 s, 232 MB/s

Well, that's a bit slower, but it's not nearly as much as I'd expect based on real-world patterns I saw over the weekend. The `sync` command is certainly slower following `dd` in the encrypted dataset, though. So, there's probably some more low-level magic at play that I don't fully grok.

[turtle]

Yeah, I didn't dig in on the commands fully either but used them as a "general test" based on this blog post I found.

I should try with random too just for comparison...

[root@knowsmore ~]# sync; dd if=/dev/zero of=tempfile bs=1M count=1024; sync1024+0 records in1024+0 records out1073741824 bytes (1.1 GB, 1.0 GiB) copied, 0.297927 s, 3.6 GB/s[root@knowsmore ~]# sync; dd if=/dev/random of=tempfile bs=1M count=1024; sync1024+0 records in1024+0 records out1073741824 bytes (1.1 GB, 1.0 GiB) copied, 2.4137 s, 445 MB/s[root@knowsmore ~]# dd if=tempfile of=/dev/null bs=1M count=10241024+0 records in1024+0 records out1073741824 bytes (1.1 GB, 1.0 GiB) copied, 0.114965 s, 9.3 GB/s

There is a drastic difference between zero and random on this DB server (on a NMVe drive). Makes me think it has more to do with the random function introducing a lag of some sort. I could be wrong, but that is WAY slower than I would expect. The DB server is basic CentOS 9 minimal with only a few applications actually running on it. Granted, the DB activity is relatively high, and it is already in production so there will be some actual use during the test... but close to a tenth of the original speed? Something is fishy there.

[Brad]

You could try with `/dev/urandom` to see if it's any faster.

random blocks when it runs low on entropy, but that seems unlikely to me in these small tests.

(urandom and random generally use the same secure pseudorandom algorithm, but urandom gracefully gives out arguably less secure values when entropy is low. The actual implementation is complicated, is different between older linux/newer linux/*bsd/macos, and is the subject of many misconceptions that I sometimes fall into too. )

[turtle]

[root@knowsmore ~]# sync; dd if=/dev/urandom of=tempfile bs=1M count=1024; sync1024+0 records in1024+0 records out1073741824 bytes (1.1 GB, 1.0 GiB) copied, 2.49076 s, 431 MB/s[root@knowsmore ~]# sync; dd if=/dev/urandom of=tempfile bs=1M count=1024; sync1024+0 records in1024+0 records out1073741824 bytes (1.1 GB, 1.0 GiB) copied, 2.42138 s, 443 MB/s[root@knowsmore ~]# sync; dd if=/dev/urandom of=tempfile bs=1M count=1024; sync1024+0 records in1024+0 records out1073741824 bytes (1.1 GB, 1.0 GiB) copied, 2.4586 s, 437 MB/s[root@knowsmore ~]# sync; dd if=/dev/random of=tempfile bs=1M count=1024; sync1024+0 records in1024+0 records out1073741824 bytes (1.1 GB, 1.0 GiB) copied, 2.45564 s, 437 MB/s[root@knowsmore ~]# sync; dd if=/dev/random of=tempfile bs=1M count=1024; sync1024+0 records in1024+0 records out1073741824 bytes (1.1 GB, 1.0 GiB) copied, 2.42391 s, 443 MB/s[root@knowsmore ~]# sync; dd if=/dev/zero of=tempfile bs=1M count=1024; sync1024+0 records in1024+0 records out1073741824 bytes (1.1 GB, 1.0 GiB) copied, 0.293834 s, 3.7 GB/s[root@knowsmore ~]# sync; dd if=/dev/zero of=tempfile bs=1M count=1024; sync1024+0 records in1024+0 records out1073741824 bytes (1.1 GB, 1.0 GiB) copied, 0.311661 s, 3.4 GB/s

They are essentially the same result.

Edit: Well.....

[root@knowsmore ~]# rsync -avP CentOS-Stream-9-latest-x86_64-dvd1.iso /tmp/sending incremental file listCentOS-Stream-9-latest-x86_64-dvd1.iso  8,747,220,992 100%  330.24MB/s    0:00:25 (xfr#1, to-chk=0/1)sent 8,749,356,665 bytes  received 35 bytes  343,112,027.45 bytes/sectotal size is 8,747,220,992  speedup is 1.00

[Yontsey]

Scanned through this thread and I'm thinking about taking the plunge with a DS920+. I have/had multiple external HDDs running to an old MBP as a media server but found out this AM that it has finally taken a shit and looks like it's dead. Need to find an easier way for a media server and it looks like this is the way to go. DS920+ might be overkill but I like being able to upgrade the RAM. I've never set up a server or anything like that so I'm pretty vanilla. Been watching YouTube videos all morning and it seems pretty straight forward. Would probably go the Plex route because it seems like a better software option than the one that comes from Synology.

Question is, how many HDDs should I get initially and how big? My externals right now are 8TB but I had some room to grow. I can't remember exactly how much off hand. If I go with 2 8TB and set them up in SHR, that will give me one for storage and one for backup, correct? If I have 4 8TB would that be 16TB storage and 16TB backup? Once again, forgive my lack of knowledge.

[Brad]

Originally Posted by Yontsey Question is, how many HDDs should I get initially and how big? My externals right now are 8TB but I had some room to grow. I can't remember exactly how much off hand. If I go with 2 8TB and set them up in SHR, that will give me one for storage and one for backup, correct? If I have 4 8TB would that be 16TB storage and 16TB backup?

SHR with just two drives means they're basically mirrored. So, two 8TB drives gives you ~8TB of usable space.

However, if you start with more than two drives, instead of mirroring, SHR will stripe the data with "parity" data across the drives. In that configuration, less than half of the total storage will be used for parity (data integrity). Four 8TB drives would give you ~24TB of usable space. The math gets weird quickly if you mix drive sizes, but if they're all the same size, then you basically "lose" roughly one's worth of capacity to store parity data.

When in doubt, Synology's website has a good calculator GUI here: https://www.synology.com/en-us/support/RAID_calculator . Click the drive sizes at the top to add them to the NAS below, or click the drives in the NAS to remove them. Then scroll down to see the effect those changes have on available storage.

Originally Posted by Yontsey one for backup, correct?

Rule number one of RAID: RAID is NOT a backup. Having multiple drives in a RAID-like configuration that uses mirroring or parity will provide you some read performance gains and can self-heal against bitrot or keep things running with degraded performance if you have one failing drive, but if you accidentally delete a file, it's immediately deleted from the mirror/parity as well. This is why storage gurus are adamant not to call RAID (or SHR or XFS) a "backup". It can be mirrored or have parity data, but it's best to pretend like that doesn't exist because you will never interact directly with it.

You gotta treat the NAS as one big hard drive. If there's anything mission-critical in there, you still want periodic backups to an external device. You may find lots of resources talking about the 3-2-1 backup rule or strategy (and I may have mentioned it earlier in this thread). One good summary from Seagate's blog here: What is a 3-2-1 Backup Strategy?

The 3-2-1 rule, attributed to photographer Peter Krogh, follows these requirements: • 3 Copies of Data – Maintain three copies of data—the original, and at least two copies. • 2 Different Media – Use two different media types for storage. This can help reduce any impact that may be attributable to one specific storage media type. It’s your decision as to which storage medium will contain the original data and which will contain any of the additional copies. • 1 Copy Offsite – Keep one copy offsite to prevent the possibility of data loss due to a site-specific failure.

That may be overkill depending on your needs, but at the very least, having a disconnected external drive that's periodically updated with a backup of your NAS's contents will put you light years ahead of most, and that'll give you an actual backup you can load in case you accidentally delete something from your NAS.

So, if you want 16TB of usable storage with a backup, you want at least three 16TB drives. Two 16TB drives go in the NAS, and one 16TB drive stays outside for periodic backup.

Originally Posted by Yontsey Once again, forgive my lack of knowledge.

Hey, we all have to start somewhere! When I started this thread, I was basically in your shoes. I had several external USB drives. I'd read a bunch of articles and wikis and watched some YouTube videos, but I'd never actually put my hands on a NAS before.

Speaking of new NASes, my DIY NAS has been rock solid for the last couple months and performance continues to be great. I've decided that I probably won't be buying a Synology NAS any time soon, at least as long as this old hardware keeps chugging along. I have used its Docker/Kubernetes capabilities a few times, and I have a long-running container for my media in Jellyfin (basically FOSS Plex), but I haven't needed to do anything with full VMs, and I doubt I will.

[Ryan]

I have a Synology NAS backed up to Backblaze. The NAS is also my Time Machine backup for my laptops, which are also backed up to Backblaze directly (I exclude the TM directories on the NAS from its Backblaze config).

[Yontsey]

Hmmm….that’s good to know that it’s not a backup.

I did mess around with that storage capacity thing on Synologys sight and that’s why I was slightly confused. In a 4 Bay, two 8TB drives is basically 8-8 but four 8TB was 24-8 and that’s what was throwing me off. For what I’m doing, the DS720+ might be enough for me. I basically just want it as a media server.

[Yontsey]

Ended up finding an old Mac Mini at work that I forgot about. It’s running 10.13 but it works none the less. Good enough to run my external HDDs through iTunes.

[turtle]

Old mini is a good file server. Easy support for macOS files systems and sharing too. Nice!

[Yontsey]

8GB of RAM and a SSD HHD in it. Runs like a champ because it's a clean install. I still want to get a Synology at some point but this buys me time. I was itching because I have all my horror movies on there and it's Halloween season.

[turtle]

I'm running Plex on my i7 Mini with a SAN connection to my NAS for the library location. So when you upgrade you would be able to do the same. Basically move your files to the NAS and update the library path to the NAS.

What version of mini is it? What is the CPU in it? Might be able to support hardware transcoding which it totally worth it if you can.

[Yontsey]

It's an oldie. It's like a mid-2011 model. I want to say 2.3ghz i5. As of right now, it does exactly what I want so I'll hold off on the Synology. I'll snag one eventually. In the mean time, I'll keep adding to my Unifi setup before we move.

[Yontsey]

Dumb question, but if I get a DS920+ and only put in 2 HDDs and do SHR, can I add a third and forth drive down the road without any issues? Does it have to do some sort of reconfig or does it just add the extra storage?

[turtle]

Not a dumb question at all.

You can add drives later with no issue at all. The NAS will rebuild the raid with the new capacity (after a little admin interaction). Your other data will be safe while it expands too.

The admin interaction is really going through DSM and telling it to add the new drive to the pool. It will do the rest from there.

[chucker]

Your disks also don't need to be the same size. Right now, I have a 3.6 TB disk, and two 7.3 TB disks. This makes for 10.9 TB actual available space, as it uses some of that disk space for redundancy, and some of it for expansion.

You can also gradually grow the SHR later on. I could eventually replace the 3.6 one with a third 7.3 TB disk, or a larger one.

[chucker]

Originally Posted by turtle The admin interaction is really going through DSM and telling it to add the new drive to the pool. It will do the rest from there.

Yup.

It was basically

1. shut the thing down
2. open it up; add a disk (which is fairly easy)
3. boot it up again
4. tell it to add the new disk to the existing pool
5. wait (many hours)

[Yontsey]

Ok good to know. I'm finishing up ordering everything for my new network rack and then next move is to probably get a DS920+. I saw they released the DS923+ but for my use, the extra money isn't worth it.

[Brad]

Originally Posted by chucker 5. wait (many hours)

This is also why it's a good idea to buy as much storage as you can afford up front: to postpone the eventual expanding/resilvering process.

Yontsey, if you can wait just a bit, there are very often hard drive sales on Black Friday (or Cyber Monday or whatever people call it now). Keep refreshing https://shucks.top (if you're willing to shuck externals) and https://diskprices.com/ (if you want to buy from Amazon) over the next couple of weeks, and you may save several hundred dollars depending on what you're looking for.

[drewprops]

I assume you all run your systems with a UPS? What happens if there is a power outage?


...

[Brad]

Originally Posted by drewprops I assume you all run your systems with a UPS? What happens if there is a power outage? ...

Most of my systems are on UPS, yes. My network router, a raspberry pi, and my NAS share one UPS. My hackintosh/desktop in another room has its own UPS. And of course laptops and phones effectively have built-in UPSes. Since the router is on UPS, if/when there's an outage, all of my essential systems are still running, and I can connect to other devices to shut them down cleanly.

Both of my UPSes have a USB data port that can signal to a PC what the current capacity is and when it's switched from mains to battery backup. I know macOS has rudimentary support for this, and I've seen options in TrueNAS, but I haven't actually configured anything around it. If I expected flakier power in my home, I'd probably configure my NAS and hackintosh/desktop to shut down automatically after a minute or so of battery-only power, but I haven't bothered.

Also, both of these UPSes start beep-screaming after several seconds of lost mains. If power went out in the middle of the night while I was asleep, I'd probably be awakened pretty quickly by the chirps in other rooms, kind of like how a smoke detector with a dying battery chirping on the other side your home will still wake you up.

[drewprops]

Originally Posted by Brad ...kind of like how a smoke detector with a dying battery chirping on the other side your home will still wake you up.

I have a small one to cushion our U-verse gateway device and I've heard that thing go off.

...

[Yontsey]

Originally Posted by drewprops I assume you all run your systems with a UPS? What happens if there is a power outage? ...

I'm getting a Tripp Lite rack mount for my network setup for my new house so when I get everything set up, I'll have it on there. We are also putting in a whole home generator too for the house. So the UPS will act as that transition if there is ever any outages. Now if I can get this house finished.....

[Yontsey]

Pulled the trigger on a DS923+ and 3 8TB HDDs. Finished buying everything for my Unify rackmount setup and wanted to get a Plex server setup before we move in the next 2 months. Running a server setup from my Mac Mini is very unreliable. Feels like every time I go to access my media server to watch a movie I have to go restart the Movie app to get access to it.

[turtle]

That is a cool NAS. I can't find where the CPU in that one will do hardware transcoding so you might run into imitations with that one being the Plex server if you have to transcode on the fly. Generally if you are streaming from that NAS to a Plex app in your home it won't be a problem unless the device is a lower res than the source.

You don't have to buy Synology RAM. I am running the RAM I linked to on pg 2 of this thread and it has been solid. Way cheaper than buying from Synology.

I would totally go for the 10Gb expansion card and connect it to your UniFi gear on a 10Gb port. Mine has been solid and while I'm not saturating the 10Gb, I'm fairly certain I would saturate a 1Gb connection.

[Yontsey]

Originally Posted by turtle That is a cool NAS. I can't find where the CPU in that one will do hardware transcoding so you might run into imitations with that one being the Plex server if you have to transcode on the fly. Generally if you are streaming from that NAS to a Plex app in your home it won't be a problem unless the device is a lower res than the source. You don't have to buy Synology RAM. I am running the RAM I linked to on pg 2 of this thread and it has been solid. Way cheaper than buying from Synology. I would totally go for the 10Gb expansion card and connect it to your UniFi gear on a 10Gb port. Mine has been solid and while I'm not saturating the 10Gb, I'm fairly certain I would saturate a 1Gb connection.

Looks like the RAM you linked has gone up in price. Would this 16GBx2 set be compatible? It's DDR4 SODIMM. In the FAQs a couple people asked about Synology compatibility, 2 said yes, 1 said no.

[turtle]

I wouldn't simply because it isn't ECC and you. You really want the higher quality server level RAM. I would go with this RAM which is speed matched for your NAS and ECC.

[Yontsey]

Thanks. I ordered 16GB. I'm going to wait on the network expansion module until I get everything set up at the new house and see how everything is set up.

[Ebby]

I just ordered the same RAM last month. What a coincidink.

Its working great, but I had to turn off the "Non-Synology module detected" nag. All good after that.

First restart takes a while. It does a RAM test. You can also manually do a RAM test in the Synology Assistant app.

Also, disable memory compression for a snappier response. You got the RAM, might as well use it.