Re: Maximum LUN support
Hi, After a little more experimenting, I think this iscsi-targets fault. I agree this does not have any relevance to the open-iscsi code, nevertheless, I though it would nice to post here as well to keep this post updated. Do apologize if that is against the principles of this mailing-list. > Interesting. That does seem like a limitation in that code. Did you > try to change the INCOMING_BUFSIZE to a higher value? Or to decrease > the length of the target's name? So: iqn.2008.com:t1, iqn.2008.com:t2, > and so on? As suggested by someone on this list earlier, I tried to reduce the target name and instantly I was able to add (made discoverable) more of the devices at the initiator side. Initially the target names consisted of about 44 characters (when only 89 devices were getting transferred across to initiator). I changed the name such that it took about 15 characters - and this time I was able to add 139 devices with the same configuration of IETd. :) Also, I changed a variable INCOMING_BUFFER (again, as suggested by Konrad) to 16384 - then I was able to add (discoverable on initiator) 179 devices with target name consisting of 44 chars. :) By add I mean, rest all the devices defined at target were being dropped by target and not sent to initiator. I had a target config list of about 1000 soft links to a valid device. > On Wed, May 21, 2008 at 12:28 AM, Mike Christie <[EMAIL PROTECTED]> wrote: > > If you are using 869.* then the problem is most likely on the IET side. > > Like I said before I think you need to upgrade. I had the same problem > > when I was testing my fixes for lots of targets support. This would certainly mean that iscsi-target is playing a game with me :D Regards Shreyansh --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "open-iscsi" group. To post to this group, send email to open-iscsi@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/open-iscsi -~--~~~~--~~--~--~---
Re: Maximum LUN support
Hi Mike and List, Thanks for the reply. On Wed, May 21, 2008 at 12:28 AM, Mike Christie <[EMAIL PROTECTED]> wrote: > > Shrey wrote: >> Hi Mike, >> >> Thanks for you reply. Please find my reply inline. >> >> On May 19, 11:04 pm, Mike Christie <[EMAIL PROTECTED]> wrote: >>> Shrey wrote: Dear All, I started using/studying open-iscsi recently. I was wondering if there is any hard-coded limit to number of targets devices that can discovered per iSCSI target? Is there any hard-coded limit on the number of LUNs supported per target device (assuming that somehow HBA on iscsi target doesn't present any limit) ? >>> As others pointed out there is a module param for the max lun for >>> iscsi_tcp, but that should actually be limited by a libiscsi/scsi-ml >>> limit. libiscsi uses a function named int_to_scsilun in >>> drivers/scsi/scsi_scan.c and as you can see that only implments 2 >>> levels. libiscsi/iscsi_tcp also does not do the device scanning (the >>> iscsi layer only finds the targets) so we are limited by scsi_scan.c. To >>> get the limits for that do "modinfo scsi_mod". >> >> Ok, that gives me something to thing/experiment about. Thanks >> >>> There is also a limit on the number of targets. Because we allocate a >>> scsi_host per session, and the scsi layer uses a unsigned short for the >>> host number the number of targets is 2^16. >> >> That would mean 65536 devices. But I get stuck far below that - just >> about 90 targets. > > If you are using 869.* then the problem is most likely on the IET side. > Like I said before I think you need to upgrade. I had the same problem > when I was testing my fixes for lots of targets support. > > Oh yeah, I said this in some other mail, but will say it here so people > can search for it. There is another target limit and that is the number > of files a process can have open. We open a tcp socket for each session > and we do a session to each target portal. We also will open other files > so the exact number is not known. I think it is probably around 4000. I > do not have a setup that supports that many targets yet to know exactly > though. Let us know what you find out. Hmm, that sounds quite a large value as against what I am experiencing. I will try and find out what is happening in my case - probably the iscsi-target is acting like some kind of bottleneck (the max size of PDU is my initial guess) - or may be I am missing something. Nevetheless, thanks for the info - i really appreciate your help. > >> Are some parameters which I am missing which I need to configure or >> take care of? >> I tried tinkering "node.conn[0].iscsi.MaxRecvDataSegmentLength = >> 65536" but there was no difference. This actually is making me think >> that target is acting as a bottleneck. >> > > That is just for normal sessions. You would want to set > discovery.sendtargets.iscsi.MaxRecvDataSegmentLength Oops - I should have noticed. Thanks once again. I will try tinkering with this. > > but like I said that will not completely fix the problem. Well, this should give me something very good to start with. I will post whatever my finding are (as soon as I find something ;) ). Thanks all. Shreyansh --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "open-iscsi" group. To post to this group, send email to open-iscsi@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/open-iscsi -~--~~~~--~~--~--~---
Re: Maximum LUN support
Shrey wrote: > Hi Mike, > > Thanks for you reply. Please find my reply inline. > > On May 19, 11:04 pm, Mike Christie <[EMAIL PROTECTED]> wrote: >> Shrey wrote: >>> Dear All, >>> I started using/studying open-iscsi recently. I was wondering if there >>> is any hard-coded limit to number of targets devices that can >>> discovered per iSCSI target? Is there any hard-coded limit on the >>> number of LUNs supported per target device (assuming that somehow HBA >>> on iscsi target doesn't present any limit) ? >> As others pointed out there is a module param for the max lun for >> iscsi_tcp, but that should actually be limited by a libiscsi/scsi-ml >> limit. libiscsi uses a function named int_to_scsilun in >> drivers/scsi/scsi_scan.c and as you can see that only implments 2 >> levels. libiscsi/iscsi_tcp also does not do the device scanning (the >> iscsi layer only finds the targets) so we are limited by scsi_scan.c. To >> get the limits for that do "modinfo scsi_mod". > > Ok, that gives me something to thing/experiment about. Thanks > >> There is also a limit on the number of targets. Because we allocate a >> scsi_host per session, and the scsi layer uses a unsigned short for the >> host number the number of targets is 2^16. > > That would mean 65536 devices. But I get stuck far below that - just > about 90 targets. If you are using 869.* then the problem is most likely on the IET side. Like I said before I think you need to upgrade. I had the same problem when I was testing my fixes for lots of targets support. Oh yeah, I said this in some other mail, but will say it here so people can search for it. There is another target limit and that is the number of files a process can have open. We open a tcp socket for each session and we do a session to each target portal. We also will open other files so the exact number is not known. I think it is probably around 4000. I do not have a setup that supports that many targets yet to know exactly though. Let us know what you find out. > Are some parameters which I am missing which I need to configure or > take care of? > I tried tinkering "node.conn[0].iscsi.MaxRecvDataSegmentLength = > 65536" but there was no difference. This actually is making me think > that target is acting as a bottleneck. > That is just for normal sessions. You would want to set discovery.sendtargets.iscsi.MaxRecvDataSegmentLength but like I said that will not completely fix the problem. > I think I will post all this on the iscsi-target list. > > Thanks a lot > > -- > Shreyansh > > > --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "open-iscsi" group. To post to this group, send email to open-iscsi@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/open-iscsi -~--~~~~--~~--~--~---
Re: Maximum LUN support
Hi Mike, Thanks for you reply. Please find my reply inline. On May 19, 11:04 pm, Mike Christie <[EMAIL PROTECTED]> wrote: > Shrey wrote: > > Dear All, > > > I started using/studying open-iscsi recently. I was wondering if there > > is any hard-coded limit to number of targets devices that can > > discovered per iSCSI target? Is there any hard-coded limit on the > > number of LUNs supported per target device (assuming that somehow HBA > > on iscsi target doesn't present any limit) ? > > As others pointed out there is a module param for the max lun for > iscsi_tcp, but that should actually be limited by a libiscsi/scsi-ml > limit. libiscsi uses a function named int_to_scsilun in > drivers/scsi/scsi_scan.c and as you can see that only implments 2 > levels. libiscsi/iscsi_tcp also does not do the device scanning (the > iscsi layer only finds the targets) so we are limited by scsi_scan.c. To > get the limits for that do "modinfo scsi_mod". Ok, that gives me something to thing/experiment about. Thanks > > There is also a limit on the number of targets. Because we allocate a > scsi_host per session, and the scsi layer uses a unsigned short for the > host number the number of targets is 2^16. That would mean 65536 devices. But I get stuck far below that - just about 90 targets. Are some parameters which I am missing which I need to configure or take care of? I tried tinkering "node.conn[0].iscsi.MaxRecvDataSegmentLength = 65536" but there was no difference. This actually is making me think that target is acting as a bottleneck. I think I will post all this on the iscsi-target list. Thanks a lot -- Shreyansh --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "open-iscsi" group. To post to this group, send email to open-iscsi@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/open-iscsi -~--~~~~--~~--~--~---
Re: Maximum LUN support
Shrey wrote: > Dear All, > > I started using/studying open-iscsi recently. I was wondering if there > is any hard-coded limit to number of targets devices that can > discovered per iSCSI target? Is there any hard-coded limit on the > number of LUNs supported per target device (assuming that somehow HBA > on iscsi target doesn't present any limit) ? > As others pointed out there is a module param for the max lun for iscsi_tcp, but that should actually be limited by a libiscsi/scsi-ml limit. libiscsi uses a function named int_to_scsilun in drivers/scsi/scsi_scan.c and as you can see that only implments 2 levels. libiscsi/iscsi_tcp also does not do the device scanning (the iscsi layer only finds the targets) so we are limited by scsi_scan.c. To get the limits for that do "modinfo scsi_mod". There is also a limit on the number of targets. Because we allocate a scsi_host per session, and the scsi layer uses a unsigned short for the host number the number of targets is 2^16. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "open-iscsi" group. To post to this group, send email to open-iscsi@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/open-iscsi -~--~~~~--~~--~--~---
Re: Maximum LUN support
Hi Konrad and list, Thanks for the reply. Please see my comments inline. On May 19, 7:13 pm, Konrad Rzeszutek <[EMAIL PROTECTED]> wrote: > On Mon, May 19, 2008 at 06:53:07AM -0700, Shrey wrote: > > > Hi all, > > > Further update on this topic: > > > > Thanks once again :) - If I manage to find/assert it, I will surely > > > post back. > > > I tried to do an experiment to confirm the maximum number of available > > targets and LUNs with an initiator. I did: > > > On the target machine: > > 1. I created softlinks for a device such that they are named /dev/link > > $i_$j where i varies from 1-100 and j varies from 0-10. Thus, I had > > links like "link1_0, link1_1, ...,link30_0,..., > > link99_0, ...link100_10". > > 2. Each link was a softlink of a valid SCSI device on the target. All > > You have actually 100 SCSI devices on your target? ohh no - I wish I had :). I have created softlinks to some valid devices. I have couple of SCSI disks, and I have created more than 100 links, spread across all of them so that not all links point to same device. This is just a ploy to make iscsi-target feel that 100 targets have been attached. Best part - it takes them silently, without complaining. :) > > > this was pushed into the /etc/ietd.conf file and service iscsi-target > > was restarted. (Yup, I am using iscsi-target-0.4.16 on the target > > side.) > > 3. This gave me 100 targets, each having 10 LUNs - starting from > > mydisk1 to mydisk100 (as target names). > > > On the initiator: > > 1. I set the discovery on this target machine IP. and tried to log in. > > > result: > > Discovery itself is not able to add more than 89 (twice I got 90) > > devices. It simply doesn't get any information about the top 11 > > devices from the ietd.conf file. > > Which is that the first target wouldn't show up right? I have added targets in ietd.conf on iscsi-target as: Target iqn.2008-04.mydevice1.com:storage.disk1 LUN 0 /dev/link1_0 LUN 1 /dev/link1_1 Target iqn.2008-04.mydevice2.com:storage.disk2 LUN 0 /dev/link2_0 LUN 1 /dev/link2_1 ... ... Target iqn.2008-04.mydevicen.com:storage.diskn LUN 0 /dev/linkn_0 Now, whichever devices are on top of this list are thrown out. Probably this as a result of some kind of target sorting as you said - but, mydevice11 should come after mydevice100 isn't it?? but it doesn't - iscsi-target simply throws (Dropping key) of top 'x' entries where 'x = y - 90' where y is total number of devices (targets) added in this list > > > On the target, the message log contained something like "Dropping key > > (target ___ )" which, I found, was appearing from text_key_add() > > function from the iscsi-target package. > > > The code is something like: > > ... > > if (conn->rsp.datasize + len > INCOMING_BUFSIZE) { > > log_warning("Dropping key (%s=%s)", key, value); > > return; > > } > > Interesting. That does seem like a limitation in that code. Did you > try to change the INCOMING_BUFSIZE to a higher value? Or to decrease > the length of the target's name? So: iqn.2008.com:t1, iqn.2008.com:t2, > and so on? Nope, I did not, though I should have. That would be my next step - thanks. I did try using different names, but i think that is not the problem because if I use the same target name as above "Target iqn. 2008-04.mydevice(n).com:storage.disk(n)" - iscsi-target is able to add mydevice100 but not mydevice1. So, I have ruled out that the target name is doing something strange. > > > ... > > > Initiator doesn't show any error, and infact the node list (iscsiadm - > > m node) doesn't display any device starting from mydevice1 - > > mydevice11 in the list. > > Which would imply that the target didn't send that IQN to the initiator. Yup, this is what even I interpreted. The output of 'iscsi_discovery ' doesn't contain the name of those devices which have been dropped and which have already been reported as "Dropping keys .." at the iscsi-target side. > > > > > I tried this experiment many times by > > 1. changing the number of LUNs, > > 2. changing the device being pointed to by the soft links, > > 3. changing the number of target devices defined in ietd, > > So you added more targets and that didn't change it, and when > you lowered the target count it would be a lower amount > of block disks showing up on the initiator side? Precisely, this is what happened. > > > 4. making half the links point to one device, and other half to other > > 5. Shuffling the order of ietd defined target names (and each time > > starting 10-11, according to definition in ietd.conf, are not send by > > target, whatever there name be). > > Yeah, it probably sorts them. OK, but still, i feel mydevice23 should come before mydevice4 - that way, mydevice23 should not be added even if it is at the bottom of the list - but that is not happening. top 10-11 devices are simply dumped. > > > > > Each time the result was same (atleast) - 89-90 can only be added. > > > I am stil
Re: Maximum LUN support
Shrey wrote: > Hi all, > > Further update on this topic: > >> Thanks once again :) - If I manage to find/assert it, I will surely >> post back. > > I tried to do an experiment to confirm the maximum number of available > targets and LUNs with an initiator. I did: > > On the target machine: > 1. I created softlinks for a device such that they are named /dev/link > $i_$j where i varies from 1-100 and j varies from 0-10. Thus, I had > links like "link1_0, link1_1, ...,link30_0,..., > link99_0, ...link100_10". > 2. Each link was a softlink of a valid SCSI device on the target. All > this was pushed into the /etc/ietd.conf file and service iscsi-target > was restarted. (Yup, I am using iscsi-target-0.4.16 on the target > side.) > 3. This gave me 100 targets, each having 10 LUNs - starting from > mydisk1 to mydisk100 (as target names). > > On the initiator: > 1. I set the discovery on this target machine IP. and tried to log in. > > result: > Discovery itself is not able to add more than 89 (twice I got 90) > devices. It simply doesn't get any information about the top 11 > devices from the ietd.conf file. When you say devices, you mean targets right? open-iscsi-2.0-869 should work. I believe iscsi-target-0.4.16 does not support lots of targets. You shuold post to the IET list. I think there are threads on this already, so actually you should search their list to make sure it is not fixed in the svn tree. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "open-iscsi" group. To post to this group, send email to open-iscsi@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/open-iscsi -~--~~~~--~~--~--~---
Re: Maximum LUN support
On Mon, May 19, 2008 at 06:53:07AM -0700, Shrey wrote: > > Hi all, > > Further update on this topic: > > > > > Thanks once again :) - If I manage to find/assert it, I will surely > > post back. > > I tried to do an experiment to confirm the maximum number of available > targets and LUNs with an initiator. I did: > > On the target machine: > 1. I created softlinks for a device such that they are named /dev/link > $i_$j where i varies from 1-100 and j varies from 0-10. Thus, I had > links like "link1_0, link1_1, ...,link30_0,..., > link99_0, ...link100_10". > 2. Each link was a softlink of a valid SCSI device on the target. All You have actually 100 SCSI devices on your target? > this was pushed into the /etc/ietd.conf file and service iscsi-target > was restarted. (Yup, I am using iscsi-target-0.4.16 on the target > side.) > 3. This gave me 100 targets, each having 10 LUNs - starting from > mydisk1 to mydisk100 (as target names). > > On the initiator: > 1. I set the discovery on this target machine IP. and tried to log in. > > result: > Discovery itself is not able to add more than 89 (twice I got 90) > devices. It simply doesn't get any information about the top 11 > devices from the ietd.conf file. Which is that the first target wouldn't show up right? > On the target, the message log contained something like "Dropping key > (target ___ )" which, I found, was appearing from text_key_add() > function from the iscsi-target package. > > The code is something like: > ... > if (conn->rsp.datasize + len > INCOMING_BUFSIZE) { > log_warning("Dropping key (%s=%s)", key, value); > return; > } Interesting. That does seem like a limitation in that code. Did you try to change the INCOMING_BUFSIZE to a higher value? Or to decrease the length of the target's name? So: iqn.2008.com:t1, iqn.2008.com:t2, and so on? > ... > > Initiator doesn't show any error, and infact the node list (iscsiadm - > m node) doesn't display any device starting from mydevice1 - > mydevice11 in the list. Which would imply that the target didn't send that IQN to the initiator. > > I tried this experiment many times by > 1. changing the number of LUNs, > 2. changing the device being pointed to by the soft links, > 3. changing the number of target devices defined in ietd, So you added more targets and that didn't change it, and when you lowered the target count it would be a lower amount of block disks showing up on the initiator side? > 4. making half the links point to one device, and other half to other > 5. Shuffling the order of ietd defined target names (and each time > starting 10-11, according to definition in ietd.conf, are not send by > target, whatever there name be). Yeah, it probably sorts them. > > Each time the result was same (atleast) - 89-90 can only be added. > > I am still trying to find what could be the possible bottleneck that > is preventing me to add more devices - till then, I would really Looks like a bug in iscsi-target. You probably show post this question on its mailing list as well. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "open-iscsi" group. To post to this group, send email to open-iscsi@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/open-iscsi -~--~~~~--~~--~--~---
Re: Maximum LUN support
Ok, I got something to ponder from one of the old discussions : http://groups.google.com/group/open-iscsi/browse_thread/thread/cc57ad9b5f571b31 (I wonder why I did not find it earlier - might be acted a little lazily!!) On May 19, 6:53 pm, Shrey <[EMAIL PROTECTED]> wrote: > Hi all, > > Further update on this topic: > > > > > Thanks once again :) - If I manage to find/assert it, I will surely > > post back. > > I tried to do an experiment to confirm the maximum number of available > targets and LUNs with an initiator. I did: > > On the target machine: > 1. I created softlinks for a device such that they are named /dev/link > $i_$j where i varies from 1-100 and j varies from 0-10. Thus, I had > links like "link1_0, link1_1, ...,link30_0,..., > link99_0, ...link100_10". > 2. Each link was a softlink of a valid SCSI device on the target. All > this was pushed into the /etc/ietd.conf file and service iscsi-target > was restarted. (Yup, I am using iscsi-target-0.4.16 on the target > side.) > 3. This gave me 100 targets, each having 10 LUNs - starting from > mydisk1 to mydisk100 (as target names). > > On the initiator: > 1. I set the discovery on this target machine IP. and tried to log in. > > result: > Discovery itself is not able to add more than 89 (twice I got 90) > devices. It simply doesn't get any information about the top 11 > devices from the ietd.conf file. > On the target, the message log contained something like "Dropping key > (target ___ )" which, I found, was appearing from text_key_add() > function from the iscsi-target package. > > The code is something like: > ... > if (conn->rsp.datasize + len > INCOMING_BUFSIZE) { > log_warning("Dropping key (%s=%s)", key, value); > return; > } > ... > > Initiator doesn't show any error, and infact the node list (iscsiadm - > m node) doesn't display any device starting from mydevice1 - > mydevice11 in the list. > > I tried this experiment many times by > 1. changing the number of LUNs, > 2. changing the device being pointed to by the soft links, > 3. changing the number of target devices defined in ietd, > 4. making half the links point to one device, and other half to other > 5. Shuffling the order of ietd defined target names (and each time > starting 10-11, according to definition in ietd.conf, are not send by > target, whatever there name be). > > Each time the result was same (atleast) - 89-90 can only be added. > > I am still trying to find what could be the possible bottleneck that > is preventing me to add more devices - till then, I would really > appreciate if there is anything anyone would like to point out. Any > hints or mistakes I am making? Hopefully, using dummy (links) is not > something "not-allowed" as per target/initiator implementation. > > -- > Shreyansh Will post back if I find anything useful/problematic Thanks Shreyansh --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "open-iscsi" group. To post to this group, send email to open-iscsi@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/open-iscsi -~--~~~~--~~--~--~---
Re: Maximum LUN support
Hi all, Further update on this topic: > > Thanks once again :) - If I manage to find/assert it, I will surely > post back. I tried to do an experiment to confirm the maximum number of available targets and LUNs with an initiator. I did: On the target machine: 1. I created softlinks for a device such that they are named /dev/link $i_$j where i varies from 1-100 and j varies from 0-10. Thus, I had links like "link1_0, link1_1, ...,link30_0,..., link99_0, ...link100_10". 2. Each link was a softlink of a valid SCSI device on the target. All this was pushed into the /etc/ietd.conf file and service iscsi-target was restarted. (Yup, I am using iscsi-target-0.4.16 on the target side.) 3. This gave me 100 targets, each having 10 LUNs - starting from mydisk1 to mydisk100 (as target names). On the initiator: 1. I set the discovery on this target machine IP. and tried to log in. result: Discovery itself is not able to add more than 89 (twice I got 90) devices. It simply doesn't get any information about the top 11 devices from the ietd.conf file. On the target, the message log contained something like "Dropping key (target ___ )" which, I found, was appearing from text_key_add() function from the iscsi-target package. The code is something like: ... if (conn->rsp.datasize + len > INCOMING_BUFSIZE) { log_warning("Dropping key (%s=%s)", key, value); return; } ... Initiator doesn't show any error, and infact the node list (iscsiadm - m node) doesn't display any device starting from mydevice1 - mydevice11 in the list. I tried this experiment many times by 1. changing the number of LUNs, 2. changing the device being pointed to by the soft links, 3. changing the number of target devices defined in ietd, 4. making half the links point to one device, and other half to other 5. Shuffling the order of ietd defined target names (and each time starting 10-11, according to definition in ietd.conf, are not send by target, whatever there name be). Each time the result was same (atleast) - 89-90 can only be added. I am still trying to find what could be the possible bottleneck that is preventing me to add more devices - till then, I would really appreciate if there is anything anyone would like to point out. Any hints or mistakes I am making? Hopefully, using dummy (links) is not something "not-allowed" as per target/initiator implementation. -- Shreyansh --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "open-iscsi" group. To post to this group, send email to open-iscsi@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/open-iscsi -~--~~~~--~~--~--~---
Re: Maximum LUN support
On May 15, 3:36 pm, Stefan de Konink <[EMAIL PROTECTED]> wrote: > On Thu, 15 May 2008, Shrey wrote: > > On May 15, 12:39 pm, Stefan de Konink <[EMAIL PROTECTED]> wrote: > > > On Wed, 14 May 2008, Shrey wrote: > > > > I started using/studying open-iscsi recently. I was wondering if there > > > > is any hard-coded limit to number of targets devices that can > > > > discovered per iSCSI target? Is there any hard-coded limit on the > > > > number of LUNs supported per target device (assuming that somehow HBA > > > > on iscsi target doesn't present any limit) ? > > > > It is a module parameter, check modinfo. > > > Thanks :) - > > defined as > > - module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO); > > - > > and has a default value of 512. > > > But is there any limit on the number of target devices that can be > > discovered per iscsi target? Something like "only x targets can be > > fetched using sendtarget from machine B to Machine A, each having > > max_lun maximum number of LUNs" > > > Thanks again for the information/help. > > Mmm... I wanted to know this last week. And in the SCSI module there is > written you can go up to 16k. But I suggest if you go above 4k to review > the time that is needed to rescan ;) > > I don't know about targets, I only checked for luns :) Thanks once again :) - If I manage to find/assert it, I will surely post back. - Shreyansh --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "open-iscsi" group. To post to this group, send email to open-iscsi@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/open-iscsi -~--~~~~--~~--~--~---
Re: Maximum LUN support
On Thu, 15 May 2008, Shrey wrote: > On May 15, 12:39 pm, Stefan de Konink <[EMAIL PROTECTED]> wrote: > > On Wed, 14 May 2008, Shrey wrote: > > > I started using/studying open-iscsi recently. I was wondering if there > > > is any hard-coded limit to number of targets devices that can > > > discovered per iSCSI target? Is there any hard-coded limit on the > > > number of LUNs supported per target device (assuming that somehow HBA > > > on iscsi target doesn't present any limit) ? > > > > It is a module parameter, check modinfo. > > Thanks :) - > defined as > -module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO); > - > and has a default value of 512. > > But is there any limit on the number of target devices that can be > discovered per iscsi target? Something like "only x targets can be > fetched using sendtarget from machine B to Machine A, each having > max_lun maximum number of LUNs" > > Thanks again for the information/help. Mmm... I wanted to know this last week. And in the SCSI module there is written you can go up to 16k. But I suggest if you go above 4k to review the time that is needed to rescan ;) I don't know about targets, I only checked for luns :) Stefan --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "open-iscsi" group. To post to this group, send email to open-iscsi@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/open-iscsi -~--~~~~--~~--~--~---
Re: Maximum LUN support
Hi, On May 15, 12:39 pm, Stefan de Konink <[EMAIL PROTECTED]> wrote: > On Wed, 14 May 2008, Shrey wrote: > > I started using/studying open-iscsi recently. I was wondering if there > > is any hard-coded limit to number of targets devices that can > > discovered per iSCSI target? Is there any hard-coded limit on the > > number of LUNs supported per target device (assuming that somehow HBA > > on iscsi target doesn't present any limit) ? > > It is a module parameter, check modinfo. Thanks :) - defined as -module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO); - and has a default value of 512. But is there any limit on the number of target devices that can be discovered per iscsi target? Something like "only x targets can be fetched using sendtarget from machine B to Machine A, each having max_lun maximum number of LUNs" Thanks again for the information/help. -- Shreyansh --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "open-iscsi" group. To post to this group, send email to open-iscsi@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/open-iscsi -~--~~~~--~~--~--~---
Re: Maximum LUN support
On Wed, 14 May 2008, Shrey wrote: > I started using/studying open-iscsi recently. I was wondering if there > is any hard-coded limit to number of targets devices that can > discovered per iSCSI target? Is there any hard-coded limit on the > number of LUNs supported per target device (assuming that somehow HBA > on iscsi target doesn't present any limit) ? It is a module parameter, check modinfo. Stefan --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "open-iscsi" group. To post to this group, send email to open-iscsi@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/open-iscsi -~--~~~~--~~--~--~---
Maximum LUN support
Dear All, I started using/studying open-iscsi recently. I was wondering if there is any hard-coded limit to number of targets devices that can discovered per iSCSI target? Is there any hard-coded limit on the number of LUNs supported per target device (assuming that somehow HBA on iscsi target doesn't present any limit) ? Actually I have a simple setup wherein Machine A and Machine B are connected over a 10Gbps Ethernet, and Machine B has a HBA to a single SCSI disk. Machine A has open-iscsi-2.0-869. Machine B is running iscsi-target-0.4.16. I wanted to know the peak capability of the open- iscsi initiator for certain study. Hope I am able to put forward my doubt clearly. I myself haven't searching for this too hard - but at least I couldn't find anything in the docs/README. Thanks in advance --- Shrey --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "open-iscsi" group. To post to this group, send email to open-iscsi@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/open-iscsi -~--~~~~--~~--~--~---