The Lemon Fool

A few weeks ago transfer speeds from my PC to my NAS (a Buffalo LS220) doubled from what they'd always been before, and have since dropped back, and I can't figure out why either happened.

I've had the LS220 for a couple of years now and always had transfer speeds to it from my PC of around 30-33MB/s. (A bit disappointing, but I'd always figured, hey, it's a cheaper end of the market NAS, so ok...).

I use it for general LAN storage and for backups and those are the figures I usually get copying files to it and also the speeds typically reported by Macrium.

That was up until a Friday three weeks ago when the Macrium logs show transfer speeds for that day and the following two days backups of 66MB/s, 64MB/s & 56MB/s, and when I noticed that in the logs on Sunday and tried copying files to the NAS I also got similarly high speeds.

Then the Monday and Tuesday it went back to the low 30s, both for copying files and Macrium, and then Wednesday it went back up to the 60s, only to drop back to the 30s a couple of days later, which is how it's been since, and I can't figure out why or, now that I know the setup is capable of better speeds, what I need to do to get those back, and keep them.

As far as I know, nothing changed over the period or leading up to it. The LS220 was on the same version of its software it had been on for ages, there weren't any Windows updates during the period, and I'd not changed anything, software, hardware or configuration, nothing at all.

So, the question is, what could be the cause of the change in transfer speeds, and, hence, what can I do to get and keep it high?

My setup is it's an LS220D0202 and it and my Win10Pro PC are connected to a gigabit switch. The LS220 runs continuously but the PC gets powered up & booted every morning and shut down & powered off every evening, and I have fast startup turned off, so it's always a from-scratch reboot. I have jumbo frames enabled all round, and at the times in question there is (and always has been) little/no other activity on the LAN.

Any one have any ideas?

https://www.servethehome.com/buffalo-ls ... as-review/
No suggestions for speeding it up but there's a review here where they get nearer to your best, with a comment from the article...

It does seem like the bottleneck is in either the CPU or the NIC.

And the bottom readers comment is from someone only getting an average of 28MB/s.

mc2fool wrote:Any one have any ideas?

Did you change in what you were working on on those days, and hence it was backing up? Larger files tend to be significantly faster on anaemic hardware.

Has it flipped between SMB V1 and SMB V2 for some reason? (I'd expect V2 to be faster and there's talk about editing the smb config if it isn't enabled by default)

Infrasonic wrote:https://www.servethehome.com/buffalo-ls220d-2-drive-nas-review/
No suggestions for speeding it up but there's a review here where they get nearer to your best, with a comment from the article...

It does seem like the bottleneck is in either the CPU or the NIC.

And the bottom readers comment is from someone only getting an average of 28MB/s.

Interesting, thanks, I'll check it out and the disk benchmarker they used tomorrow. (I'll bet the guy getting 28MB/s doesn't have jumbo frames enabled ... he's also going through his router).

xeny wrote:

mc2fool wrote:Did you change in what you were working on on those days, and hence it was backing up? Larger files tend to be significantly faster on anaemic hardware.

Has it flipped between SMB V1 and SMB V2 for some reason? (I'd expect V2 to be faster and there's talk about editing the smb config if it isn't enabled by default)

No to all. In any case, Macrium writes huge single image files and measures actual I/O throughput, and when I did my timing tests I did it by copying single very large files.

SMB 2 is enabled all round, both on the NAS and the PC, and every time I've checked (PowerShell Get-SmbConnection) it has been using it, but I suppose there is the possibility it's flipping behind my back. I need V1 turned on on the PC 'cos of a served drive on my router, but I'll do some experiments with it tomorrow.

Well, turning off (removing) SMB V1 altogether from my PC made no difference, so we can exclude any surreptitious flipping of SMB versions used, and the disk benchmarking tool used in the article linked to by Infrasonic gives the same 30-30MB/s figures as Macrium and just plain file copying do.


https://imgur.com/a/PIvNfHt

Can you try connecting it directly to the PC NIC (might require a crossover cable)
- that will remove the chance of anything in the switch affecting it and give you your theoretical max rate between the two devices

If that doesn't make any difference it implies the bottleneck is internal to one of them (or it was misreporting the faster transfer speeds)
- do you know what the drives are in the NAS? Could they be hybrids? that could give different write speeds for different locations on the disks
though at the sizes of test transfer shown I'd expect it to be working mostly with a RAM cache than waiting for a spool to disk

-sd

Well, I've found the proximate cause. Just out of curiosity I thought I'd see what it was like with SMB V1 and ...



and that's totally reproducible, SMB V1 speeds are twice those of SMB V2!

The LS220 can be configured to have either one or both turned on, with both it switching automatically (presumably depending on what clients request) and that's the default, so clearly while it mostly used V2, at the times when it was unusually fast it must have been using V1.

Now, the question is, is it the LS220 that's the cause of the difference or is it something about my Windows SMB V2 configuration? A google for SMB V1 faster than V2 got me to:

https://social.technet.microsoft.com/Fo ... nservergen and links from and further googles from there have found:
https://social.technet.microsoft.com/Fo ... networking and then
https://docs.microsoft.com/en-us/window ... le-server/ along with
https://docs.microsoft.com/en-us/powers ... w=win10-ps

The two technet articles recommend setting the various cache lifetimes to zero, which I've tried but that didn't help. I've also tried disabling bandwidth throttling, as that looked like an obvious one to try, but also to no effect....

Is something like Wireshark worth giving a go?
https://www.google.com/search?q=wiresha ... e&ie=UTF-8

Infrasonic wrote:Is something like Wireshark worth giving a go?
https://www.google.com/search?q=wiresha ... e&ie=UTF-8

Ugh. Dunno. Looks like a pretty steep learning curve, and learning the SMB protocol wasn't on my wish list! Unless there is something easy to look for?

mc2fool wrote:

Infrasonic wrote:Is something like Wireshark worth giving a go?
https://www.google.com/search?q=wiresha ... e&ie=UTF-8

Ugh. Dunno. Looks like a pretty steep learning curve, and learning the SMB protocol wasn't on my wish list! Unless there is something easy to look for?

I had a play with Wireshark in my Linux container on my Chromebook some time ago and came to the same conclusion, it's not something you can really busk without a good understanding.
There are loads of specific tutorials out there, but as you say it's how much time you want to commit to it for what might well be a minimal return.