Slow Disk Acces

[lyzanxia]

I have the exact same board, and also get around 40mb/s. Cpu is not very busy at that moment. If I initiate 2 cifs copy operations at the same time, I get twice +-40mb/s. So I guess its got something to do with the cifs implementation? Ftp gets me around 60mb/s.

 

[joeschmuck]

You know, after posting I was thinking about CPU usage. Even mine doesn't get hit hard but I still think it's CPU related. You probably have much higher transfer rates writing to the NAS and slower reading from the NAS. That is my situation. As I understand it it does have to do with calculating the parity for comparison but I could definitely be incorrect. Maybe, just maybe it's a small amount of mathematics but it just takes too long to calculate it. So don't think of it as your CPU not being maxed out, think of it as only one thread and the CPU isn't fast enough for that single calculation. See if that sounds right. If someone else has a better explanation I am all ears.

As for it being Samba, I'm sure it plays a role here if you're getting faster FTP speeds.

 

[Ryle]

1) You may need to use something like GParted to delete all the partition info on them before formatting for UFS. I thought the developers fixed Destroy Volume to wipe out the first and last areas of the hard drives which I thought would fix that problem.

Ok I will try to fully erase disk with another tool and test in UFS

quick point, with the proper hardware, I've gotten 4 gb/s (2 in 2 out) from FreeNAS (cifs, ftp, rsync via ssh).

When i Google 'E35M-I AMD E350' i see a board that only has passive cooling. It's a long shot but maybe you've got a heat problem and your CPU is under clocking itself when it gets to hot?

Ok that confort me, Yes cooling is passive but I put a 12cm fan on Heat pipe, and for the moment tower is fully open (At it is a self modify tower I have still work to do on it :D) So I don't think it's a overheating problem but by the way it would be nice to have CPU temperature under Freenas WebGui

I have the exact same board, and also get around 40mb/s. Cpu is not very busy at that moment. If I initiate 2 cifs copy operations at the same time, I get twice +-40mb/s. So I guess its got something to do with the cifs implementation? Ftp gets me around 60mb/s.

Ok that confort me too.
But what I doesn' understood (and I have re-tested it) is on the first boot of nas max transfer 30MB/S, just do reboot and here I go up to 60MB (and when using multiple transfer up to 75MB), that client do you use for FTP, I retry with FileZilla and I still have max 3MB/s. What is your exact hardware configuration and what settings did you use for ftp and cfis ??

You know, after posting I was thinking about CPU usage. Even mine doesn't get hit hard but I still think it's CPU related. You probably have much higher transfer rates writing to the NAS and slower reading from the NAS. That is my situation. As I understand it it does have to do with calculating the parity for comparison but I could definitely be incorrect. Maybe, just maybe it's a small amount of mathematics but it just takes too long to calculate it. So don't think of it as your CPU not being maxed out, think of it as only one thread and the CPU isn't fast enough for that single calculation. See if that sounds right. If someone else has a better explanation I am all ears.

As for it being Samba, I'm sure it plays a role here if you're getting faster FTP speeds.

Yes I try to watch CPU usage (By the Way, under freenas webGui, why is max cpu % scale set to 200% , is there a way to change that or to have bigger graph ?) and my cpu is stuck to 100% during file transfer E350 is a dual core CPU, is Freenas really using it ?

I test transfer speed In reading and surprisly it's worse than for writting

Antoher things that just happen: I was transfering about 15GB of files and suddently transfer stopped! Nas was still running but no more connection (no ping) but network was ok (can access my adsl box) and whithout doing anything connection came back !
As i have no screen on nas is there some log I can access through WebGui ???

Another question: I know that on XP there's some limitations on Ethernet (bandwith?) is there something like under Win 7 ???


Thanks for all your help !

 

[matthewowen01]

each logical cpu gets it's own 100%, you have 2 logical cpus. if it was a quad core with hyper threading, you'd have 800%.

to better monitor things, can you connect a monitor and use the 'top' command at the console.

 

[lyzanxia]

I use filezilla too, using 2 transfers at the same time (set it in options in filezilla). My hardware config is the same e350 board,8gb ram,raidz1 4*2tb wd greens.
My cifs settings is like it is default in freenas. My ftp setting is 3 connections and the rest default.
cpu scale 200% is because you have a dual core I suppose.

 

[joeschmuck]

@Ryle,
Let us know what your results are once you change over to UFS. For testing purposes you could just use a single drive. If that works, then do all the drives. I played around with many configurations testing throughput and UFS is by far faster. It's not safer but if you're only streaming videos then that is not really that important if you lose it or there is a little file corruption. If you are storing valuable data, consider using a mirrored ZFS for your data and the other drives for UFS for video and not so valuable data.

 

[Ryle]

@Ryle,
Let us know what your results are once you change over to UFS. For testing purposes you could just use a single drive. If that works, then do all the drives. I played around with many configurations testing throughput and UFS is by far faster. It's not safer but if you're only streaming videos then that is not really that important if you lose it or there is a little file corruption. If you are storing valuable data, consider using a mirrored ZFS for your data and the other drives for UFS for video and not so valuable data.

It will be mainly for video, so yes UFS with raid 5 is enough, but I thought putting together personal document but I don't want to use 4To for about 2G of doc :). I thought that the main avantage of ZFS was to avoid writte hole (and so be a bit faster)

So I still try UFS and here are my results:

UFS 1 disk alone:

First boot
- Write: ~27MB / Transfer speed not stable but better than RaidZ / CPU usage ~10% / Mem Usage <1GB
- Read :~35MB / Transfer speed not stable worse than RaidZ

second boot :
Idem ( maybee slighly worse)

UFS 4 disk in striping:
First boot
- Write: 66MB / Transfer speed stable / CPU usage ~40% / Mem Usage <1GB (If I correctly read the chart I have 4Go of inactive memory !! what that's )
- Read :85MB / Transfer speed stable

second boot :
- Write: 30MB / no stable !!! What the fuck I haven't change anything why do I always have completely different behaviour between 2 boot ???

third boot :
Idem....


I will try tomorrow to directly connect my pc and the NAS to get rid of switch even if I don't really believe that my problems are coming from here....

 

[joeschmuck]

I like the speed you were getting with the RAID-5. I don't have a clue how to read those charts most of the time. I think they try to display too much information on a single chart. It would be nice to select what is or isn't displayed.

I don't understand what is going on with your machine. You're not overclocking anything are you?

ZFS avoiding the write hole is only one part of ZFS. The other part is data integrity where it calculates parity during the reading and this is where things take a bit more time.

To be honest, I hope it's your switch just so you can get past this problem.

 

[Ryle]

Truth is elsewhere...

Ok folks, I have done some test, and there something strange:

I try with a direct connection between PC and NAS => Same behaviour, switch are not in cause.

Being quite despaired, I try a foolish things: I installed Windows 7 on NAS !!!

I first installed HDtune and test all 4 disk to see If I haven't a small black duck in my HDD family :p
Result are a quite homogeneous except for one disk which have a better "stability" than the 3 others why ?? I currently have not clue (can post HDDtune screenshot if needed)...

Obviously no Software raid with Windows, so just use a simple share on each drive and see what happens:
- Write : 70 MB/S (get to 90MB on disk with windows can tell why :p)
- Read : 110 MB/S

that's the best I had, but I see something really strange when reading/writing from NAS, for example:
Transfer start at 10MB for ~2 sec and then blackout no more com with nas (even with a direct ping !!!) for about 15s and after that 10s at 40MB/S and next about 110MB
Every next transfer was stuck directly at 110 MB ...

After some more test I see that I have random blackout during transfer, I thing that I will buy a pci-express network card to do some test (are they easily compatible with freenas ??? )

 

[Ryle]

Yes...

Hi everybody!

I finally found what cause me so much pain !
It was the network card of my main PC (embedded of course....) I put a PCi-express Ethernet card and no more blackout and finally descent speed even in ZFS (even after several reboot):

Write : 60 MB/S (Network more or less stable but no more blackout)
Read : 90MB/S (Network stable)

UFS:

Write : 90 MB/S (Network stable)
Read : 110 MB/S (Network stable)

Ok now that my speed issues are finally over, I'm trying to test data security, and there again another problem:
4 Drive RAID-Z:
- Wiping one disk => getting error when trying to replace disk

4 Drive UFS striping
- Wipping one disk => Disk status is Down but I have no possible action....

(wipping method: Put disk under windows => create one full partition, then clean disk using diskpart)

Did I miss something

Thanks for all your help and support