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davebctx

globalSAN v5 performance with Synology DS1511+

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I've recently started using globalSAN v5 with my Synology DS1511+ and have found that read performance from the drive is extremely poor.

The XBench results for it give the following:

Sequential:

Uncached Write 149.72 91.93 MB/sec [4K blocks]

Uncached Write 100.58 56.91 MB/sec [256K blocks]

Uncached Read 38.16 11.17 MB/sec [4K blocks]

Uncached Read 1.57 0.79 MB/sec [256K blocks]

Random:

Uncached Write 225.33 23.85 MB/sec [4K blocks]

Uncached Write 191.36 61.26 MB/sec [256K blocks]

Uncached Read 1492.74 10.58 MB/sec [4K blocks]

Uncached Read 4.25 0.79 MB/sec [256K blocks]

I didn't have this sort of performance problem with the previous version of globalSAN. Is there anything I can do about this - it's making my photo library practically unusable.

Dave

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I had the same problem with read performance on an OpenFiler iSCSI connection. Write performance was fine.

I created a new user who had no startup items and didn't have a problem with read/write performance with this user. I have since found that it is an issue with the number of applications I had open at the time I did the connection to the GlobalSan initiator volume - Using gsutil to connect.

Since I only used the iSSCI connection during an overnight backup (ie. wake-on-lan the OpenFiler, connect to the volume using gsutil, backup using rsync and SuperDuper (sparse bundle), disconnect the volume, use gsutil to disconnect the iSCSI connection and then remotely shutdown the OpenFiler) - Since my case was rather unique I did not expect that other users would experience the read performance issue and have not logged it.

I presumed it was due to a buffer allocation issue with the number of open/running applications limiting what GlobalSan could use - It seems to be a 32 bit application and may be limited to memory below 4GB. I have 8GB in my MacMini Server.

I have since converted the OpenFiler to an NFS share as an interim measure, as the GlobalSan Initiator seems to be a bit flaky and I could not guarantee the read speed without logging off/on into the other user - This has taken me over 2 weeks to complete, as I have to rewrite most of a 1,000 line bash script for my backups.

I have saved a copy of the old iSCSI bash script and would revert to it in a heartbeat if the read performance could be guranteed with GS V5 - but at the moment I am not holding my breath and will regularly test GS V5 as new versions are released.

I think tthe read performance issue is only being experienced by a minority of users - most users will keep their drives connected constantly and will not experience the issue.

As you have stated I did not have this problem with GS V4 and SL 10.6.7 - But since moving to GS V5 and Lion 10.7.2 the problem became apparent.

Hope this helps,

Tom.

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Hi,

I had the same problem with read performance on an OpenFiler iSCSI connection. Write performance was fine.

I have tested my COMSTAR iSCSI targets on two of my Macs, a Mac mini 2009 and a MBP 3,1, 2.2 Ghz. The performance using GS v.5 seems to be the same as the previous GS initiators I used on those machines. Actually reading 4k or less blocks has always been slow, while transferring greater blocks shows a good performance:

Sequential

Uncached Write: 123,23 MB/sec [4K blocks]

Uncached Write: 55,26 MB/sec [256k blocks]

Uncached Read: 9,5 MB/sec [4k blocks]

Uncached Read: 94,65 MB/sec [256k blocks]

Random

Uncached Write: 19,09 MB/sec [4K blocks]

Uncached Write: 59,54 MB/sec [256k blocks]

Uncached Read: 2,18 MB/sec [4k blocks]

Uncached Read: 94,72 MB/sec [256k blocks]

Transferring small block sizes always results in a speed impact, but as you can see, transferring bigger block sizes results in reasonable transfer speeds.

Cheers,

budy

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Actually reading 4k or less blocks has always been slow, while transferring greater blocks shows a good performance:

Hi Budy,

Can you confirm the below

a) Do either of your Macs have greater than 4GB Ram?

B) Start a good number of applications (e.g iTunes, Safari, Mail, MS Word, MS Excel - About 10 or so apps should be enough - mixture of 32bit & 64bit)

C) Unmount the iSCSI Volume & disconnect the LUN

d) Connect the LUN - Volume should auto mount

e) Re-run the performance stats and see if the read performance is the same?

Thanks,

Tom.

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I've recently started using globalSAN v5 with my Synology DS1511+ and have found that read performance from the drive is extremely poor. The XBench results for it give the following: Sequential: Uncached Write 149.72 91.93 MB/sec [4K blocks] Uncached Write 100.58 56.91 MB/sec [256K blocks] Uncached Read 38.16 11.17 MB/sec [4K blocks] Uncached Read 1.57 0.79 MB/sec [256K blocks] Random: Uncached Write 225.33 23.85 MB/sec [4K blocks] Uncached Write 191.36 61.26 MB/sec [256K blocks] Uncached Read 1492.74 10.58 MB/sec [4K blocks] Uncached Read 4.25 0.79 MB/sec [256K blocks] I didn't have this sort of performance problem with the previous version of globalSAN. Is there anything I can do about this - it's making my photo library practically unusable. Dave
Hi Budy, Can you confirm the below a) Do either of your Macs have greater than 4GB Ram? B) Start a good number of applications (e.g iTunes, Safari, Mail, MS Word, MS Excel - About 10 or so apps should be enough - mixture of 32bit & 64bit) C) Unmount the iSCSI Volume & disconnect the LUN d) Connect the LUN - Volume should auto mount e) Re-run the performance stats and see if the read performance is the same? Thanks, Tom.

Thank you for providing these details. I have been able to replicate this behavior in our lab with a Synology iSCSI Target and we are investigating the behavior. We will report back with more information pending our further analysis.

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Same here , also a synology (DS209+II). Need this fixed fast please. Write ~50MB/s, Read 0MB/s

Its running on a machine i can not just reboot every time to get it back to normal as it also runs live websites/mailserver etc.

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Any updates on this . I am sure we are not the only once. Never had that problem with the free version.Now i "bought" the latest version my NAS is useless at the moment (even after reboot same problem. Write ok , read near zero mb/s.

First time i had to pay for a "downgrade" ;-)

Holding of on buying another 3 copies for my other workstations until solved.

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I filed a case this weekend and was contacted by SNS to send them a tcpdump trace so they can more easily investigate the issue. So if you also have this issue, do the same to help SNS solve this. I guess the more different traces they have the better to zoom in on the problem.

-----cut-------

Thank you for your ticket. We have been working on this issue, but it has been rather elusive to consistently replicate and analyze.

It would be very helpful if you could please send us traces for 30sec - 1min from your system when it is experiencing the poor read speeds.

Collecting traces for troubleshooting iSCSI issues is very simple using the terminal window and the tcpdump command that comes with OS X.

The command requires using sudo, which means that you will need to provide an administrative password to run the command. This command does not make any changes to the OS, so it is safe to run.

Using the syntax below will, however, capture all of the traffic between your workstation and the target machine. The use of CHAP security may hide some of the important troubleshooting data. Also, this capture may reveal values of CHAP secrets, so if you are using CHAP authentication, please disable it before running this command.

Here are the steps:

1) Prepare the following command in a terminal window (but don't run the command until you reach the point of the slow read speeds):

sudo tcpdump -i {interface} -n -s 0 -w {output file} host {ip addr or hostname of target}

Note:

{interface} is the ethernet interface that the OS X machine uses to talk to the target. Use the ifconfig command to determine the correct interface. This should be something like en0 or en1.

{output file} is the file name for the captured traffic. This is the file that you will send to us when the capture is complete.

{ip addr or hostname} is the address or hostname of the iSCSI target device, in this case your Synology. This filters the capture to just traffic to and from the target.

for example:

sudo tcpdump -i en1 -n -s 0 -w target.cap host 192.168.1.250

2) Connect to your target using the globalSAN initiator and initiate a benchmark test or transfer that will display the slow read speeds. Then hit the Enter key in the terminal window to start the TCP dump.

3) Let the TCP Dump run for 30 seconds to 1 minute capturing the slow read speeds. Then use <Control>-c to end the tcpdump command in the terminal window.

4) Send the resulting output file to us in reply to this email ticket. If the file is quite large, let us know how big it is so that we can arrange some other method of delivery.

----- cut-----

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I filed a case this weekend and was contacted by SNS to send them a tcpdump trace so they can more easily investigate the issue. So if you also have this issue, do the same to help SNS solve this. I guess the more different traces they have the better to zoom in on the problem.

Would love to help but I was running a trial version that has since expired. I am not shelling out the $ until I know it's going to work right...

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Would love to help but I was running a trial version that has since expired. I am not shelling out the $ until I know it's going to work right...

Same here, trial has now expired.

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Good news guys.

Today i got a beta version to test and (sofar) all seems fixed. Even after a few reconnect and a fully loaded server.

Will keep it running for a few days but seems like the sns boys took it really serious and found the issue.

I had to re-register and that got me an extension on the trial at the same time, so assuming SNS releases the fixed beta (or a full ) version , you should have so more playtime before buying.

If it stays stable for the entire trial i will dig in and buy some licenses.

Good support sofar ! Have seen much worse.....

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I am having read bad read performance too...

any way to post a link to the beta for testing any release plans...

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I'm running iSCSI 5.0.0.286 on a MacBook Pro connected to an Synology 1511+ with a trial license. Also I'm not satisfied with the read speed and for me it's currently a show stopper.

I need to mention that the iSCSI initiator solved all my other problems like the time machine backup.

So if this gets fixed ….

Glenn

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Hi all :)

Testing on my iMac27" 2011 and 1511+, moving an 4GB movie file to the iSCSI partition, takes 2mins.

Copy it back to the mac, takes 2hours.....

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I received a mail after submitting a request on the read speed issue...

MacBook Pro Directly connected using 1GB network I'm hitting 75MB/s Writing and 100MB/s reading speed.

Results 130.36

System Info

Xbench Version 1.3

System Version 10.6.8 (10K549)

Physical RAM 8192 MB

Model MacBookPro6,1

Drive Type SYNOLOGY iSCSI Storage

Disk Test 130.36

Sequential 83.02

Uncached Write 136.39 83.74 MB/sec [4K blocks]

Uncached Write 104.68 59.23 MB/sec [256K blocks]

Uncached Read 40.50 11.85 MB/sec [4K blocks]

Uncached Read 151.40 76.09 MB/sec [256K blocks]

Random 303.27

Uncached Write 265.35 28.09 MB/sec [4K blocks]

Uncached Write 190.79 61.08 MB/sec [256K blocks]

Uncached Read 1592.85 11.29 MB/sec [4K blocks]

Uncached Read 281.54 52.24 MB/sec [256K blocks]

Thanks a lot for the fast response!

Glenn

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Did some Xbench tests, storage shared over SanMP:

Results 8.38

System Info

Xbench Version 1.3

System Version 10.7.2 (11C74)

Physical RAM 16384 MB

Model iMac12,2

Drive Type SYNOLOGY iSCSI Storage

Disk Test 8.38

Sequential 5.72

Uncached Write 140.51 86.27 MB/sec [4K blocks]

Uncached Write 95.30 53.92 MB/sec [256K blocks]

Uncached Read 39.21 11.47 MB/sec [4K blocks]

Uncached Read 1.52 0.77 MB/sec [256K blocks]

Random 15.67

Uncached Write 178.78 18.93 MB/sec [4K blocks]

Uncached Write 175.32 56.13 MB/sec [256K blocks]

Uncached Read 1576.76 11.17 MB/sec [4K blocks]

Uncached Read 4.11 0.76 MB/sec [256K blocks]

And here is some results from Ubuntu:

ubuntuiscsi.jpg

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Wow. Communication and support is fantastic here. Glad I didn't purchase. For double the price ATTO solution looks well worth it now. I understood the lack of the aforementioned when the software was free, but having an expiring trial license requiring eventual purchase when there are clearly issues is a non-starter for me.

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I have been testing a beta build which has been working great with no read / write speed issues. If I want to purchase a permanent key will it work with the beta build currently on my machine or is it only good for the current stable release? Do we get the initial discounted price since many of us would have purchased but the initial build did not work with our Synology NAS solutions?

Thanks

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I have been testing a beta build which has been working great with no read / write speed issues. If I want to purchase a permanent key will it work with the beta build currently on my machine or is it only good for the current stable release? Do we get the initial discounted price since many of us would have purchased but the initial build did not work with our Synology NAS solutions?

Thanks

Yes, the permanent key will work with the beta.

Please send us the email address used to activate the trail so we can check your account for the original activation date.

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Do we get the initial discounted price since many of us would have purchased but the initial build did not work with our Synology NAS solutions?

Same question here - as "us" Beta testers have helped to improve the product and pointed out some of the issues with the first release. Maybe it is time for a post festive season sale :D

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Yes, the permanent key will work with the beta.

Please send us the email address used to activate the trail so we can check your account for the original activation date.

Thanks Ryan... who do I email with the address I used to activate the original version back in October to get the discounted price?

Thanks a lot!

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Thanks Ryan... who do I email with the address I used to activate the original version back in October to get the discounted price?

Thanks a lot!

SNSRyan... Are you here?

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