Advantages/Disadvantages of Synology Hybrid Raid?

[Intel70]

Hi All,

Bought a DS411 the other week, loving it and am excited about DSM 4.1!

I bought 4x WD20EARX WD 2TB Green drives to go with the NAS. Set them up in RAID 5 instead of SHR, for no particular reason.

I've had zero problems so far and everything's running perfectly. Though I just read about potential problems with consumer drives in RAID configurations, thanks to a lack of TLER functionality. I understand that thanks to the software RAID used in Synology NAS's, potential TLER issues are much less of a problem compared to hardware RAID.

My Question: Besides the significant flexibility options offered with SHR, as well as less wasted space in some circumstances, are there other advantages to running a Synology NAS with SHR over traditional RAID? More reliable overall? No difference? Any specific info in regards to no TLER in consumer drives?

Essentially I'm wanting to know; before my drives fill up should I take the time to move my data off the NAS and recreate my volume with SHR? Am I worried over something that's really a non issue for a home NAS?

Thanks in advance!
Intel70.

[Meinaart]

I would try to migrate to SHR if you can still easily do it. If you need more storage in the future (which you probably will ) you can upgrade in steps instead of all disks at once and also with a lot less waste of space. I think this is a big advantage. Also, it makes it easier to migrate your volume to a diskstation with more bays.

You probably already know this links but still good to look at them again .
http://forum.synology.com/wiki/index.ph ... id_RAID%3F
http://www.synology.com/support/RAID_ca ... hp?lang=us

Especially the raid calculator is a nice tool to see the differences between SHR and RAID 5.

So it has mainly to do with easy upgradability in the future, which is a big advantage if you have a 6TB volume (not easy to backup all data when it's full to migrate to SHR later on).

[halkx]

OK...I have a DS2411+ with 5x3Tb and 7x2Tb as SHR-1...The volume reports 23.23Tb in size whereas the raid calculator feature in synology website indicates 26Tb for my setup...am I missing something? (the difference seems to be a 3tb disk...).

Also, I am waiting for a DX1211 which I plan to load with 12x2Tb disks and expand the current volume...what kind of size increase should I expect?

Thanks Michael

[HarryPotter]

The size is ok. A official called "2 TB disk has about 1.81 TB space (about minus 10%, which is what you get).
A volume with a 3 TB disk cant be expanded with 2 TB disks. Better create a new independent one.

[halkx]

The size is ok. A official called "2 TB disk has about 1.81 TB space (about minus 10%, which is what you get).
A volume with a 3 TB disk cant be expanded with 2 TB disks.

so you are saying that I need to create a second volume on the expansion?

That's odd...I don't want to replace the 3tb disks on the 2411 with 2tb ones...I want to add new disks on the dx1211...surely it is logical that SHR would add the capacity of the new disks to the current volume?

[HarryPotter]

It has been discussed about a million time on this forum: you cant add a smaller HD than the biggest existing one to a volume!

And anyway: IMO it is not advisable to spread a volume over multiple devices. To risky for failing.

[halkx]

I hear you...will create a second volume then...

[neo77]

Dear all - I just purchased a DS212j.

For the moment I want to run the following setup:
Drive1: Hitachi 2TB 7k3000 deskstar
Drive2: Hitachi 640GB (from my 2009 MacPro)

I don't require RAID redundancy, etc and just wanted to drive 1, the brand new deskstar as a single drive with most of my stuff on it. The 640GB, the older drive is loud and clunky and I want to have it in the NAS for just maybe occasional use.
I backup Drive1 on an external Caviar Green of similar size.

Googling around I found that what I was looknig for was called a 'JBOD configuration'. However, I had real trouble finding a way to set it up like this in the DSM and ended up creating 2 separate Volumes (Volume 1 = 2TB new Hitachi and Volume 2 = 640GB old Hitachi). However, the DS212j formatted each of the drives in Synology Hybrid RAID.

My Q is - could I leave it this way - i.e. two independent volumes, each formatted in SHR or should I somehow try to format the two disks as 'JBOD' ?
The formatting took ages. Is there any drawback on running SHR on just a single disk ?

Apologies if this sounds silly, I'm a total newby with NAS/servers and I couldn't find a post that answered my Q anywhere. If there is, again, I apologise.

I'd be most grateful for anyones view.

Best Regards,
Neo

[savy]

Q: Is there any drawback on running SHR on just a single disk ?

If you do that you loose the biggest advantage of the physical data redundancy among more that one hard drive however "paying" for all side effects.

In your conditions I would go with 2 separate JBOD volumes.

[neo77]

Q: Is there any drawback on running SHR on just a single disk ?

If you do that you loose the biggest advantage of the physical data redundancy among more that one hard drive however "paying" for all side effects.

In your conditions I would go with 2 separate JBOD volumes.

Great, thanks, makes 100% sense.
I was just wondering what the actual side effects are ? I haven't found any in my googling ...

[savy]

- lower read/write speed/transfer-rate
- reduction of ~50% of available volume space (due to RAID redundancy)

[wiremonkey]

Just FYI, I had two 2TB hard drives in a DS411 as SHR RAID. I added two more identical 2TB drives two days ago and it's still expanding! I think the whole process to expand about 600GB of data to all four drives using SHR RAID will be almost 3 days! So, be prepared to have your system down for quite some time when you expand folks. I'm sure you can access files, but I don't think it's a sound idea during data manipulation.
Cheers,
Tyler

[jwshrive]

I'm hoping this is the correct thread to post in, and I'm sure this is answered within this topic somewhere but there's a fair bit of information to sort through. Therefore, I'm hoping this will be a quick question and answer here.

I purchased a DS411 a few months back and it is serving its purpose admirably. I originally purchased 2 x 2TB drives and set them up with SHR, but soon realised this would not be enough as I started to do backups on a regular basis and my media library expanded. Therefore, I purchased 2 x 3TB drives to expand my storage. Now, I've still got plenty of space, with 6.25TB in total. Obviously I have lost some space though due to starting the SHR with 2TB drives. Therefore, if in the future I purchase 2 x 3TB drives to replace the older 2TB drives, will I actually gain any space, or will I need to redo the entire setup first?

[Eideen]

...Therefore, if in the future I purchase 2 x 3TB drives to replace the older 2TB drives, will I actually gain any space, or will I need to redo the entire setup first?

You will gain space, just replace 1 disk at the time, to allow the volume to rebuild.
http://www.synology.com/support/faq_sho ... 1&lang=enu

[jwshrive]

Thanks for the response. I was hoping that would be the case, but I wasn't sure. No worries about letting the volume rebuild - that makes perfect sense. This gives me an upgrade path, though I shouldn't need it for at least a year. Of interest, are 4TB drives supported?