Synology DS1513+ Perfomance hits - iSCSi

Radian

Member
Mar 1, 2011
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Just configured a new DS to replace a Windows Storage server that is hosting CSV, configured the same MPIO settings as the old Windows NAS (Redundant nics and switches dedicated for iSCSi) but I'm seeing a big performance hit compared with the old windows NAS.

VM startup is awful, very slow and opening start menu in guest VM you can see a definite pause. When running on the old windows NAS VM's operated perfectly.

I'm using a Iscsi LUN block IO with multiple paths enabled (DSM indicates four initiator connections active). Anyone having performance problems with their DS? Any settings need adjusting?

I do notice that my MPIO setting on the new DS target is "Round Robin subset", whereas the windows NAS MPIO is set for "RoundRobin".
 

voodooFX

Active Member
Jan 26, 2014
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MTU?
Can you see traffic through all the interfaces?
Have you tried any benchmark on a VM?
 

Jaesii

New Member
Feb 6, 2016
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I too have terrible performace with Synology.

I have 2 hosts connected to the synology using 10GbE DAC cables. My Datastore latency is all over the place. I also have poor VM startups.

I've tried 9000 MTU and this makes little improvement. I have a sever I use for storage testing. Moving a file from one local drive to another, I never get over 50MB/s. It should be flying on 10G ethernet.
 

mattr

Member
Aug 1, 2013
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Pretty much any ARM/Atom based NAS has terrible performance. I have a QNAP TS-563 (2GB model) and I wasn't even seeing 50MB/s with it. I enabled write caching which got me up to 80MB/s. Increasing the RAM to 16GB got me up to 120MB/s limited by GbE. However it's not consistent. On large files it'll dip down to 60MB/s then back up to max. On my Windows/Linux Xeon/Core file servers They just flatline at 120MB/s. I basically just use my NAS devices for backups and Dropbox-like solutions.
 

Jaesii

New Member
Feb 6, 2016
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My synology is an intel i3 with 8GB ram and 10GbE. It shouldn't give me crap performance.

Here's what I get on my Synology. The Array consists of 5x WD Enterprise 2TB drives and 2 SLC SSDs for R/W cache.


Heres my FreeNAS SAN with just 8x HGST consumer 1TB 2.5 drives and no cache.
 

bds1904

Active Member
Aug 30, 2013
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What type of raid are you running on the synology? That's where I would start. Also, just because they are SLC drives doesn't mean that are decent drives for the task you are using them for. What kind are they? How is the cache configured? For some reason I can't remember how synology deals with 2 cache drives by default.

You could also have a crap disk in the pool. Did you do a bad blocks before putting them into the synology to see if their performance was up to par individually? I've seen that with plenty of 2TB WD drives. As a matter of fact I had to RMA ~200 of 500 drives purchased in 3 lots because of poor access times (1.5 seconds+), bad blocks, poor spin up times etc. That's 200 bad drives that were factory fresh. Hence my "no WD for me" policy but I wasn't the one that made the call on purchasing the drives, but I digress.

Also, enable sync-writes (sync always) on that FreeNAS to see the (lack of) performance a non-ram-backed write cache gives you. It'll give you an idea of what to expect for writes out of the synology.
 
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