iSCSI Support for ReadyNAS

You most likely got here by looking for the “iSCSI Target Support for ReadyNAS“. Unfortunately, your quest isn’t over yet, since the downloads have moved to a new location. This way it’s easier for me to release updates and, to be frank, it’s easier for you to find them.


I will still update this page whenever there’s a new release available.

Current iSCSI Releases for ReadyNAS:

    This is the current release built from the “stable” branch of the iSCSI Enterprise Target Project

56 thoughts on “iSCSI Support for ReadyNAS

  1. Pingback: iSCSI Target Support for ReadyNAS updated — WhoCares?

  2. Pingback: ReadyNAS goes iSCSI — WhoCares?

  3. Jan-Piet Mens

    Thanks a lot Stefan — I have iSCSItarget_0.4.17-readynas-1.0.1 running on RAIDiator 4.1.5 and nothing got bricked. ;-)

    One small thing: the docs say, in step #7, to shut down the iscsi target after the line “… Rebooting”. I believe that should be after the closing fi of the if block.

  4. Pingback: Jan-Piet Mens / iSCSI Support for ReadyNAS updated

  5. Stefan Rubner Post author

    You’re right of course. Netgear changed the


    script with RAIDiator 4.1.4 and I completely forgot to update the docs. Thanks for the heads-up. The documentation in the Wiki is fixed now.

  6. Jonas

    I’m really lost, i know nothing about ssh i’ve installed everything but the part about configuring the device or the file i cant. Please advise step by step for dummies…

  7. Stefan Rubner Post author

    Actually I was under the impression that the information given here for the .bin version was as close to a step by step guide than you can get.
    I revised the documentation a bit now to make it clearer. Or at least I hope so. If that’s still not good enough I’d need more information about the specific problems you encounter.

  8. Pingback: » Creating an iSCSI target on a Netgear ReadyNAS

  9. Nathan

    I’ve got the service installed, LUN file created, config file in place, and service running seemingly happily. However when I attempt to connect to the target from an initatior there are no LUNs presented. I’ve capture the iscsi traffic in Wireshark and confirm good a successful login and the the initiator asks for all targets, but the response packet doesn’t list any targets. I’m guessing I’ve goofed somewhere, but I’m just not seeing it. Are there any logs anywhere that I could view to see what I’ve screwed up? :)

    Have tried both and 1.4.18 (when the more recent showed this problem). Current test lun file is 10GB.

  10. Stefan Rubner Post author

    There may be a problem with the location of the config files. Please check whether you have a working copy of ietd.conf in /etc/iet/ which is the new location where the daemon looks for it’s config.
    The installer *should have* taken care of that but it seems that it doesn’t in all cases.
    Logs should be available in the syslog or the kernel log, depending on the type of error the iSCSI daemon reports – if any.

  11. Jason Morgan

    I need to be able to have the same files visible on the readynas as on the iSCSI target.

    So using a file container would not be an option (unless I locally mount the iSCSI virtual disk using an initiator on the NAS).
    If instead of using a file container I use an LVM target, would this allow simultanious access to the filesystem from the NAS device and a remote initiator, without bricking the entire thing?

  12. Total Stranger

    Firstly, awesome addon for the ReadyNAS, thanks heaps.

    Just testing transfer speeds over the LAN to the ReadyNAS, CIFS vs iSCSI, and CIFS is beating the iSCSI target nearly two fold. :(
    Does anyone know of any configuration options that can improve the performance of iSCSI?

    Also, I second Jason’s question, can you target a device (I’m assuming by doing Lun *blah* Type=blockio)?

  13. Stefan Rubner Post author

    Well, yes, you can target a device – but you’d have to create that in the first place and I wouldn’t want to mess with the ReadyNAS that much. Also I would like to discourage the parallel use of the device used for the iSCSI target unless you add another file system layer like GFS or OCFS2 since iSCSI was never meant to handle that kind of abuse ;)
    As for the tuning issue: you can try to play with the settings in ietd.conf. In addition tuning the TCP/IP stack on the ReadyNAS can be helpful. There’s not general rule what will help and what will make matters worse but there’s a lot of hints out the on Google.

  14. Tony Cooper

    I have been using iscsi 1.4.18 that i have had install and has worked fine for about 8 months now. about a week ago the iscsi volume started reporting disk errors in windows and therefor disabled VSS. The readyNas RND4000 reports all disks are fine. Any ideas as my iscsi volume is 2tb in size and would take a week to run a full scandisk

  15. Stefan Rubner Post author

    That the RND4000 reports all drives as fine unfortunately doesn’t say anything about the state of the iSCSI volume. Since the iSCSI volume essentially is just a file to the RND4000, chances are that the overall structure of the file itself is ok. However, the filesystem structure contained within that file may well be damaged without the RND4000 having any chance to detect that.
    Such errors can only be detected by the machine connecting to and using the iSCSI target. So my advice would be to trust your Windows error message and at least run a simple check on the iSCSI volume from your Windows host.

  16. Jørn Wildt

    Is it possible to use the iSCSI drive from the NAS (Duo) itself? Can the various pre-installed services under the standard web-admin see the disc and use it for streaming media? How about access control?



  17. Stefan Rubner Post author

    No, they can’t, at least not with this add-on. Wouldn’t make much sense anyway since an iSCSI device on the NAS itself is just a mere file on the main storage of the NAS itself. If you’re looking for a way to make the NAS use an external iSCSI disk, you might want to have a look at the open-iscsi add-on. Using this you can connect external iSCSI drives to the NAS and you should then be able to use them. I have to admit I haven’t tested this yet, so you’re on your own there.

  18. Jørn Wildt

    Okay. I am asking because I want to backup my NAS using Mozy … but Mozy does not support network drives. I friend told me that a drive on my PC mounting an iSCSI drive would be backup-able by Mozy from my own PC. But that doesn’t help much if I can only backup stuff that the NAS cannot use.

    Thanks for the reply.


  19. Mike Patnode

    Downloaded and installed After following the instructions verbatim, I realized my target was not being created and spent a lot of time searching the net for the cause of this message:

    iscsi_trgt: iscsi_target_create(131) The length of the target name is zero

    I finally came back here and read all the comments. The problem the whole time was ietd.conf needs to be /etc/ietd, not /etc like the instructions say. :-( Hopefully google will find this comment for the next guy who comes along.

    Two other quirks:
    1. If you don’t specify –adress=IP on the command line, you get the following error message:

    medianas:/etc/iet# ietd -d2 -f
    1284248763.537724: created target
    1284248763.556602: unable to create server socket (Address family not supported by protocol) 10 1 6!

    That said, it doesn’t seem to effect the functionality, so I suspect it’s an effect of the ANY/ANY in targets.allow.

    2. The start/stop scripts aren’t managing the pid file correctly:
    medianas:/etc/iet# /etc/init.d/rfw-iscsi-target start
    Starting iSCSI Target: ietd.
    medianas:/etc/iet# /etc/init.d/rfw-iscsi-target stop
    Stopping iSCSI Target: ietdNo /usr/sbin/ietd found running; none killed.
    medianas:/etc/iet# ps -ef | grep ietd
    root 5196 1 0 16:46 ? 00:00:00 /usr/sbin/ietd
    root 5221 4026 0 16:48 pts/1 00:00:00 grep ietd

    I haven’t bothered trying to debug this yet.

    That said, great software! It’s the only solution to make my Media Center machine diskless (aside from the SSD).

  20. Mike Patnode

    Finally, I’m seeing an almost 6x improvement in my iSCSI writes vs SMB from Windows 7 to the ReadyNAS, but a 2x slow down on the read:

    SMB Performance via LAN Speed Test
    “Computer Name:”,”HTPC”
    “IP Address:”,”″
    “MAC Address:”,”00-0A-CD-1A-87-98″
    “Number of Test Packets (1-100):”,”100″
    “Packet length:”,”1,048,576 × 100″,”1,048,576 × 100″
    “Avg time / packet:”,”0.0299100″,”0.0218100″
    “Time to complete:”,”2.9910000″,”2.1810000″
    “Bytes per second:”,”35,057,706″,”48,077,762″
    “Bits per second:”,”280,461,648″,”384,622,096″
    “MBps (Mega-Bytes)”,”33.4336338″,”45.8505268″
    “Date:”,”08-29-2010 at 17:54:12

    iSCSI Performance via LAN Speed Test
    “Computer Name:”,”HTPC”
    “IP Address:”,”″
    “MAC Address:”,”00-0A-CD-1A-87-98″
    “Number of Test Packets (1-100):”,”100″
    “Packet length:”,”1,048,576 × 100″,”1,048,576 × 100″
    “Avg time / packet:”,”0.0052300″,”0.0454900″
    “Time to complete:”,”0.5230000″,”4.5490000″
    “Bytes per second:”,”200,492,543″,”23,050,692″
    “Bits per second:”,”1,603,940,344″,”184,405,536″
    “MBps (Mega-Bytes)”,”191.2045889″,”21.9828529″
    “Date:”,”09-11-2010 at 17:14:40″

    No noticable difference with IOmode=wb.

  21. Stefan Rubner Post author

    As to the bugs: I’ll see what I can do about the stopping not working as expected. The other thing is that the ReadyNAS is simply missing IPv6 support, that’s what the “unable to create server socket” is all about. The read slowdown as shown in your tests may be due to the fact that the iSCSI target acts just like a disc. So it will profit from not checking any permissions and also it doesn’t have to bother with all the compatibility issues introduced with Windows 7 and Samba. This may explain why writes are faster. That reads are slower on the iSCSI target is most likely attributed to the fact that the iSCSI target doesn’t do any caching whereas the SMB daemon does. So if the test is going to re-read the same file over and over, SMB is likely to be faster than the iSCSI target.

  22. Mike Patnode

    Thanks! That all makes sense. It looks like the performance is perfectly adequate to record 2 HD streams and playback 1 simultaneously. That’s all I really need though it’s always fun to try to squeeze out a little more.

  23. Stefan Rubner Post author

    Well, you may want to play with the WThreads settings in ietd.conf …

  24. Pingback: Blog » Jumbo Frames, iSCSI and Disabling Nagle

  25. Ajnick

    Hi, great addition for the readynas duo if only i could get it to work. I have installed the latest version and created a test LUN of 40Gb. The service is running but I cannot get the globalSan initiator to see the LUN. I am using Mark Wilson’s instructions I don’t get the configure targets option only one to donate (which I have done). Any help would be great.

  26. Ajnick

    I have an update when rebooting the readynas I do get connected then disconnected from the iSCSI target so I presuming this will be a permissions issue I have not altered the ietd.conf file apart from changing the LUN to blockio and setting the alias as ReadyNas

  27. Welf Mahlke


    somehow I can’t get your iscsi addon running on my ReadyNAs NV+! I have radiator 4.1.7 installed. Furthermore I installed the ssh- enabled Addon and the Toggle Addon. After all I installed the latest iscsi Addon. I use PUTTY to get a ssh connection to my ReadyNAS. SO far so good. I read your instructions and copied the command with the config file in Putty command line. That worked also. But the I tried to copy the command “Lun 0 Path=/c/iscsi_0,Type=fileio” into the command line in PUTTY and after Enter it says “bash: Lun: command not found“ ! Then I created a 40 GB file with the command “dd if=/dev/zero of=/c/iscsi_0 bs=10485760 count=4096“ as you said in the instructions. I waited till the command line appeared again. But when I want to find the Target with the windows iscsi initiator Windows /), I cannot find any target.

    I have now tried to get this working for three days and almost near to give it up. I also tried it on another ReadyNAS NV with Windows XP (I got seven ReadyNAS NV integrated into my two Networks at Home and at Work) but without any success. I will give you a donation for your effort, but first of all I have to get this ADD-on to work. Does anybody have an idea?

  28. Welf

    Now, at this point I have to say: Great Support and a very nice Contact. Couldn’t have been better. Thanks a lot and have a nice vacation!!!

  29. misterhee

    Hi Stefan.

    I have installed the new readyNAS 4.1.8 firmware (to get time machine backups working again). After this I installed iSCSItarget_1.4.20.2-readynas-1.0.5. I followed all install instructions successfully with no errors reported / iscsi_0 created etc.

    However either windows nor Mac can see the iscsi on the ReadyNAS when scanning for a target/portal etc.

    When I ssh into the readynas and run stop() on rfw-iscsi-target (even after manually running start()), I get the following:

    ReadyNAS:~# /etc/init.d/rfw-iscsi-target stop
    Stopping iSCSI Target: ietdNo /usr/sbin/ietd found running; none killed.

    I have a feeling that the daemon is not actually running properly etc.

    Can you please let us know if the current iSCSItarget_1.4.20.2-readynas-1.0.5.bin is compatible with firmware 4.1.8?

    Thanks in advance,

    (sorry for the double post – please delete the message I posted in the contact section)

  30. Steve Dolphin

    Hello there,

    Firstly, thank you for taking the time and effort to develop an add-on which provides iSCSI access – it’s surprising this isn’t built in (it is in other ReadyNAS models, but not the NV+ as I’m using).

    I have installed it and after playing with the command prompt for a couple of days I have had no luck at getting a target mounted in Windows 7.

    dd completes without issue (although, note: I tried to make a +2TB volume without realising that there was a limitation in dd – of course there is but I just didn’t think) – has anyone found how to make a 2TB+ LUN? gpart doesn’t seem to exist on this build.

    The target name appears in the initiator and I can connect to it, but it then doesn’t appear in the disk management console for me to mount to a drive letter – I’ve tested a different iSCSI target and it works fine – is it perhaps that I’m using the minimal config? Do I need a proper target name to mount it?:

    Lun 0 Path=/c/iscsi_0,Type=fileio

    Unrelated – there is a slight bug as highlighted previously in that the “stop” command does in fact not stop the daemon – a “ps” still shows the daemon running – from what I can tell this is because the PIDFILE is wrong, despite you specifying /var/run/ the output is actually /var/run/ – I changed the service script to match and it now starts and stops correctly.

  31. Steve Dolphin

    Update: I fixed my main problem (target advertised but couldn’t connect): a typo difference between the file name and the config file (one was _0 (zero) and the other was _o (the letter O)).

  32. Steve Dolphin

    Okay, final post today: I’ve got this working fine now, the only issue is that (running 4.1.8) the throughput speed is just awful – I can’t find any reference to what you think the throughput for your iSCSI driver vs. the normal CIFS share should be, but in my tests today it’s running at about 50% (11MB/s with iSCSI, 23MB/s without).

  33. Pingback: ReadyNAS NV+ and Encryption (TrueCrypt) « Steve Dolphin

  34. Gary Parker

    Hi Stefan, just wanted to say thanks for this really useful addition to the ReadyNAS Duo and mention a few gotchas I worked around:

    – the GlobalSAN iSCSI Initiator for OS X went to a 14-day trial as of v5 but you can still get the last free version in their “legacy” folder here:

    Version is working just fine in my OS X 10.7.3 machines.

    – I installed the iSCSItarget_1.4.20.2-readynas-1.0.5.bin package on my ReadyNAS Duo (Sparc) running 4.1.19 and had to fix the following:
    – ‘/etc/init.d/rfw-iscsi-target’ references the wrong PIDFILE, it should point to ‘/var/run/’
    – ‘/etc/init.d/rc3’ and ‘/etc/rc6/S99reboot’ didn’t get the entries put in to start and stop the daemon respectively. I followed the instructions here ( and added ‘/etc/init.d/rfw-iscsi-target start’ and ‘/etc/init.d/rfw-iscsi-target stop’ in the requisite place and it’s working fine now.

  35. Hamal Terry

    On the error when stopping, and the LUN not appearing when started, I’ve traced it to a typo in the /etc/init.d/rfw-iscsi-target script.

    Line 10 should read:


    And not:


    I made the change, and like Steve, things began to work for me.

    Additionally, on line 3o, there’s this:

    modprobe iscsi_trgt

    Not sure if it’s legit, so I left it.

    Hope this helps everyone having issues, and Stefan, thanks again for this great software you’ve written!! Kudos!

  36. QatQat (Antonio)

    Hi Stefan,

    thanks for the wonderful piece of software. it works perfectly on my readyNAS DUO.
    I am also experiencing great performance but unfortunately only on small(ish) files.
    To give an example, if I transfer a 500MB file to a CIFS share (over a 1GB LAN) the avg transfer speed will be approx 14mb/sec.
    Doing the same over a NFS share it varies between 15 and 17MB/Sec

    Moving the same file to an iSCSI target on the same DUO i experienced an incredible 50 to 65Mb/sec.
    Seek performance is also fantastic but only for short bursts.

    It looks like the unit runs out of steam if involved in a longer execution. I cannot explain why but the same tests run for larger files (over 2GB) or higher number of small files give completely different results.

    When transferring a single file of approx 4GB the final transfer speed will be 8-10MB/sec

    when transferring loads of small files (cannot quantify how many) for over 2 minutes performance get down to kbytes/sec .

    Is there any reason for this? The drives in the unit are 2 x 2TB Western Digital (30 days of life).
    I experience the same with or without Jumbo frames enabled.

    What else can I try to avoid this behavior and stabilise the good performance I experience with smaller files?

    Thanks in advance for you help.


  37. Stefan Rubner Post author

    Antonio, you can try to increase the number of worker processes for the iSCSI daemon (WThreads config statement). But since the Sparc cpu in the Duo isn’t really the fastest one available, you should try to tune carefully there. Also you can experiment with the size of the different buffers (Send/RcvDataSegmentLength) but again: carefully. Putting more RAM into the ReadyNAS may help as well for it will allow the NAS to buffer more of the file in memory before writing to disk.

  38. QatQat (Antonio)

    Thanks for your prompt reply. I will run some tests trying to finetune the config file and eventually post back the results, although I think that increasing the memory may be also be a good thing to do.



  39. QatQat (Antonio)

    Hi Stefan,

    I have purchased a 1GB memory module for the unit. I will install it and run tests this afternoon.
    Concerning the number of worker processes my WThreads is currently set to 3. What would be an ideal setting?


  40. QatQat (Antonio)

    Ok, here are some results.

    small file access has increased trememdously. The unit seems to put everything in memory and then write later but that’s ok for me. Files are anyway immediately availble for opening.

    Write speed also has improved quite a lot

    a 2.35GB file was transferred at an average of 14.39Mb/sec
    a 1.6GB file was instead transferred at an average of 31.02 Mb/sec

    Indeed the unit is now much more usable as iSCSI target for my laptop as well as my CentOS 6.2 Server or my Win2008 server without noticeable delays.

    I have not tried it with two initiators connected at the same time but that would be asking too much from a home NAS unit.

    I will try to increase the number of WThreads and get back if I notice anything worth mentioning.


    Thanks again for your valuable piece of software and your support.

  41. Chris Hibberd

    Hi All,

    I know this is an old Add-on, but its been brilliant for testing and well, playing, but I was wondering, as I know nothing about programming etc. will it ever support Hyper-V Failover?, I found the post below by you, but I just wondered if its never going to be supported or can’t be supported, or just needs adding

    The iSCSI target on the ReadyNAS NV/Duo/… doesn’t support the needed feature of “reservation” of iSCSI targets.



  42. Stefan Rubner Post author

    Actually there byy now is a version – at least in the iSCSI target project’s SVN repository – that supports iSCSI reservation and thus could theoretically be used together with Hyper-V. That said, there’s a catch: the latest version of the iSCSI target requires a more modern kernel than the one installed on the Sparc line ReadyNAS boxes. If time permits I’ll try to backport the necessary stuff as I did before, but since the changes this time are rather massive I doubt there’s chance to really make it happen. As an alternative I could look into providing a newer kernel for the ReadyNAS but that would obviously be a major task. So don’t expect anything in the near future ;)

  43. Chris Hibberd

    Thanks for the reply,

    Its a shame it will take you a long time, its a good add-on and we use both my old Duo’s for testing, sort of cheaper iScsi storage, Failover was the next challenge and we kept getting the errors about the “reservation/iScsi-3?” thing, we googled it and found your post about it not being supported…..needed a coffee and a sit down after that disappointment, not in your add-on i mean, just the fact it was’nt supportted and the post was 2 years old

    is it something you could provide instructions on? I would guess it would be wayyyy over my head though, I would offer to pay, but the money I have probably would not cover two cups of coffee :-(

    Thanks, and if you do manage to update it I will be happy to test it :-)

  44. Mark Fletcher

    Like Chris, I too have recently installed the iSCSI add-on onto my ReadyNAS NV+ and think it’s great – very simple to set up and get working when you follow the instructions. However, like some others I also found the performance also slow (I’m using multiple LUNs for one target all configured as fileio), but I have the stock standard 256Mb installed. Awaiting a delivery for a 1Gb module and hopefully that will alleviate the issue I’m seeing (slow transfer rates) as it appears that memory is used for caching.

    Reading up about fileio vs blockio, fileio appears to be the preferred option but obviously incurs an overhead on the host (perhaps the SPARC just doesn’t have enough in the way of horsepower?). Do you think blockio would be a better option for us NV+ users? I guess an option is to use Flex-RAID and configure the drives as RAID5, then use blockio?

  45. Mark Fletcher

    Oh and BTW – like Chris, I too would seriously consider investing in pursuing the option described for Reservations – Stefan, would you entertain it? I am sure that others would be willing to pledge a donation for the continuing development of this module!

  46. Stefan Rubner Post author

    The blockio directive -if I recall correctly – is for use on block devices only. Since on a ReadyNAS with standard configuration there’s no way to create/use a new block device this only leaves fileio to access the virtual filesystem.
    As for the reservations: I will definitely look into that but time is still a luxury I don’t have much of right now.

  47. Arslan

    HiDid you manage to find an awensr to the targets not being found or advertised? Im having exactly the same issue I tried the suggestion of just downloading the ietd.conf direct to the /etc but still no joy. The daemon is running fine I can connect to it without issue but no targets appear. I have tried three different systems still no joy and also 2 NV+ boxes both with the latest firmware and latest ISCSI add on. If I use SSH explorer I can see the target in /c and the ietd is configured to point at it. The only thing I can think of is both NV+ boxes were already configured and had data on them so something is remiss as their seems to be some other issues with front view. For example if i click on the shutdown and reboot they dont do it I have to do a reboot through SSH. If I click on the reset to factory default under upgrade it pretends to do it for about 10 seconds and doesnt. Can i factory reset through SSH? I have backed up all the data so no issue there.

  48. Stefan Rubner Post author

    Have you created the target files and also changed the ietd.conf accordingly? What’s the version of the iSCSI add-on you’re trying to use?


  49. Eric Marcus

    hi, on my readynas duo I have two 2tb disks in a mirror, it was all shared as CIFS. I’ve set up the iScsi target as a 1 tb file and connected from Windows 7 without any problem. I then deleted my cifs shares and recreated the iscsi file to fill my whole disk mirror and that worked fine. however, when I connect from windows 7 iscsi initiator the target is still seen as only 1 tb. Is this a persistent setting on the readynas or in windows? where to look?

    My intent, by the way, is to make this the repository for my home esxi server.


Leave a Reply

Your email address will not be published. Required fields are marked *