I have a spare 240GB SSD - Will I gain anything

[Grantp]

My current setup is

Motherboard - SuperMicro X9SCM-F
RAM - 32GB Kingston ECC
H.Drives - 8x3TB estern Digital Reds in a mirrored Raidz2
FreeNAS - 9.1.1 Release

I have a spare 240GB Corsair Neutron SSD and was wondering if it was worth installing into my FreeNAS box.

After doing some reading I don't believe I need it as a ZIL as I only have CIFS shares on my box.
And according to what I've read in CyberJocks PowerPoint Presentation the max size should be 140GB when used as L2ARC (I.E. 7/8 of memory x 5).

So as I've said earlier will there be any advantages gained in installing said SSD into my current system?

Many thanks Grant

 

[cyberjock]

Honestly, if you haven't proven that you actually need it, don't put it in. Adding complexity where it is unnecessary is not recommended. Your system is well built with the hardware you linked. Don't break it by trying to add stuff you don't need. :)

 

[Grantp]

Thanks for reply, I don't know if I have proven if I need it or not. Response times seem very laggy to me. For example, if I open a CIFS directory containing 243 top level folders I can sit with a blank screen for 10 seconds before it populates the window. If I open a folder that has MP3 files in each MP3 files has embedded album art that doesn't show until I click on the file then refresh the window. Is this down to the fact it is a CIFS Networked drive (is that just the nature of networked drives) or am I missing some setting/tuneables or something. Would having L2ARC help this in any way?

I have read the many post regarding the slow directory listings using CIFS so looks like I have to live with that but what about the album art and such like not displaying

 

[cyberjock]

Thanks for reply, I don't know if I have proven if I need it or not. Response times seem very laggy to me. For example, if I open a CIFS directory containing 243 top level folders I can sit with a blank screen for 10 seconds before it populates the window. If I open a folder that has MP3 files in each MP3 files has embedded album art that doesn't show until I click on the file then refresh the window. Is this down to the fact it is a CIFS Networked drive (is that just the nature of networked drives) or am I missing some setting/tuneables or something. Would having L2ARC help this in any way?

I have read the many post regarding the slow directory listings using CIFS so looks like I have to live with that but what about the album art and such like not displaying

Hard to say for the directory listing. I'm pretty sure directory listings aren't cached. But, you also need to figure out where the limitation is(this goes back to my original post of you have to prove that an L2ARC could help). If the pool is reading like crazy for 10 seconds and then your directory is listed, then an L2ARC might help(again, if you are assuming it will cache directory listings). On the other hand if the server hard drives blink and then your desktop waits 10 seconds for the reply, an L2ARC is pointless(regardless of if it caches listings or not).

It's really hard to say for the album art. The L2ARC is not a read-ahead cache, so you're still going to have slow reads until the cache fills(and it doesn't fill very fast). It's more like trying to fill a 1 gallon jug by collecting drips of water from a leaky faucet. As for album art and stuff, that's VERY dependent on alot of factors. The program that I use caches the album art locally on the hard drive in a database, so my album art appears within 2-3 seconds for my entire collection.

There's also tons of settings that you can enable/disable that can cause bad behavior(such as slow directory listings). On my old Windows Desktop my Symantec Antivirus would make directory listings randomly take about 30 seconds. Some directories had less than 5 files! Through investigation I proved it wasn't my server randomly misbehaving but was my firewall. Now I run linux and I get better CIFS speeds than I ever got on Windows. :)

So again, unfortunately, all I can say is you should prove that your pool is the limitation before you go farther. Keep in mind that L2ARC steals RAM from the ARC, so you can end up with a slower server overall when adding an L2ARC. You can conceivably solve one problem while creating another.

 

[Grantp]

Thanks again for your reply. I really don't know Linux so when you say 'you have to prove that an L2ARC could help' how do I do this. From Windows 7 if I run CrystalDisk I get these results which I think are fairly good results

I tried Unchecking 'Support DOS File Attributes' in the CIFS settings (mentioned in another thread and now MP3 Album Art comes up instantly. But when I open up a folder full of MP4 (Video) files this is what I get

1) When first opened up I see this

All the folders appear to be empty

2) When first opening one of the above folders I see this

3) This never displays the thumbnails until I single click on each one then update/refresh window. I then see this, this is the display I always get if disk is local.

4) When closing this folder I then get this display, showing content in the folder unlike earlier.

If I then close down explorer and come back to it sometime after the thumbnail displays are all still there (As in Pic 3 and 4) so I am assuming (with the little knowledge I have) that these have been cached in some way.

I don't know if any of this is to do with CIFS, the fact it's a networked drive or something else. If it's just the way it is I will live with it but if there is something I can do to make it display like I am used to seeing in Windows 7 then that would be great.

 

[cyberjock]

Thanks again for your reply. I really don't know Linux so when you say 'you have to prove that an L2ARC could help' how do I do this. From Windows 7 if I run CrystalDisk I get these results which I think are fairly good results
View attachment 2845

For starters, FreeNAS is built from FreeBSD, which isn't linux.

Second, you prove it not by running diagnostics but by reading up on ZFS and seeing what your cache's are doing. There's a whole bunch of commands you can run and you have to interpret all that data. In some cases where you have a super busy server in an enterprise environment an L2ARC is naturally benefitial. For home users, virtually useless. Trying to optimize ZFS is far beyond the scope of this forum, and many people spend weeks/months trying to figure it out without success.

As for your other issue with thumbnails, there's no way to know what the limitation is. The program that generates those thumbnails might default to not creating them from network shares so you don't overload the network shares all at once. There's no easy way to tell you what your situation is because there's so many ways that troubleshooting could go. It could be a bug with Explorer and whatever program is generating the thumbnails. I don't know. I could give you at least 50 scenarios of possible causes that aren't related to your server at all.

You really are on your own to figure it out since your choice of software packages surely doesn't match mine. I browse my network from linux, and I don't enable the thumbnails because I don't want to deal with the delay while it gives me a thumbnail of 100 files over a minute or so. When I used to use Windows I always disabled them because they are slow.

One thing I do know is nobody has posted with a problem like yours for the thumbnails, so I have to assume its less likely to be a server-side issue.

 

[Grantp]

Ok thanks again for your reply. My bad calling it Linux, in my ignorance and little knowledge of Linux I recognized commands like ls, vi, rm, cd / etc as Linux commands.

I will leave as is as it's not really a problem, I am just used to Windows displaying thumbnails instantly no matter how many files are in the directory.

Thanks for all your help and I'll just put my spare SSD away and forget about it, as it has no current use.

 

[John M. Długosz]

I was speculating that besides for sustained speed, a SSD front-end can allow the drives to sleep more. And avoid that long delay when they are waking up, and save power. Especially if the spin-ups are staggered.

 

[cyberjock]

I was speculating that besides for sustained speed, a SSD front-end can allow the drives to sleep more. And avoid that long delay when they are waking up, and save power. Especially if the spin-ups are staggered.

The L2ARC is not a read-ahead cache. It's actually quite complex and doesn't work like a "dumb cache" like you are probably used to. Couple that with the fact that the L2ARC doesn't cache everything and only trickle fills with data you shouldn't expect a drive to sleep more. Not to mention having drives sleep seems to shorten their lifespan significantly.

Let's also keep in mind that the likelihood he'll want to watch the same movie 10 times in a row(thereby making it likely to be partially in the L2ARC)is pretty slim.

 

[John M. Długosz]

What about the directory structure and such?

Calling it an ARC implies that it remembers the last stuff read from slower media, kicking out some older stuff. It is the name of a specific algorithm, which is a "smarter" LRU.

 

[Grantp]

Well all my thumbnail / album art problems appear to be sorted. I rebooted my FreeNAS box and all art / thumbnails are displayed instantly.

 

[Dean Collins]

Thanks for reply, I don't know if I have proven if I need it or not. Response times seem very laggy to me. For example, if I open a CIFS directory containing 243 top level folders I can sit with a blank screen for 10 seconds before it populates the window. If I open a folder that has MP3 files in each MP3 files has embedded album art that doesn't show until I click on the file then refresh the window. Is this down to the fact it is a CIFS Networked drive (is that just the nature of networked drives) or am I missing some setting/tuneables or something. Would having L2ARC help this in any way?

I have read the many post regarding the slow directory listings using CIFS so looks like I have to live with that but what about the album art and such like not displaying

Wow as a potential new user you seem to have pretty high end equipment....to have these laggy results seems concerning to me.

I have a thecusn7700 i'm looking to replace (I had to replace a motherboard earlier this year and am concerned about the proprietary costs so looking for commodity hardware) if this is the best results FreeNas can offer maybe its not for me.

 

[cyberjock]

There are plenty of reasons for long directory list delays. Most people have one or more issues related to zpool performance, firewall performance, album art/thumbnails, and network performance.

FreeNAS performs quite well assuming you give it good resources, but that doesn't solve any of the other problems. Especially regarding the album art/thumbnails causing slowdowns, that's a Windows problem, so you are on your own to solve those. I will say that Linux doesn't have many of the slowdowns because it prioritizes displaying the directory list before loading up album art/thumbnails.

In short, FreeNAS hasn't really been found to have a bug directly causing the issues.