Hi! Just a note of curiosity: Several years ago I wanted to test some RAID configurations, but had no server with enough disks. However the server had a lot of RAM (by that time). So I ended with creating a few small ramdisks which I exported as iSCSI devices. The host was happy with those "disks". In the meantime the devicemapper can even inject "I/O errors", so maybe you can build a useful scenario for some basic tests. Like this: --- DEV=bad_disk dmsetup create "$DEV" <<EOF 0 8 zero 8 1 error 9 7 zero 16 1 error 17 255 zero EOF ---
Regards, Ulrich >>> Bobby <italienisch1...@gmail.com> schrieb am 06.11.2019 um 22:49 in >>> Nachricht <0c2592cf-ad61-4fe4-8006-63edabe4a...@googlegroups.com>: > Hi Donald, > Hi The Lee-man, > > Thanks for the reply. Both replies were helpful and both replies actually > clarified my concepts. And I realized, the question was not clear....You > were kind enough to reply in detail even when the question of was not clear > ! > > *The Lee-man*, your guess was right. I was thinking something like that and > I realized it makes no sense. > > *Donald*: Yes, you are right. I took this point of yous "*then doing normal > I/O to that iSCSI disk will provide all the traffic you will typically > need*"....the > wireshark showed me ! > > I'm a novice in Open-iSCSI yet very much interested in it. Please excuse my > simple questions. It is written, Open-iSCSI acts as "*kernel driver*" > between "*block layer*" and "*network layer*". Therefore following two > questions: > > - Linux block layer perform IO scheduling IO submissions to storage device > driver. If there is a physical device, the block layer interacts with it > through SCSI mid layer and SCSI low level drivers. So, how *actually* a > software initiator (*Open-iSCSI*) interacts with "*block layer*"? I will > be really grateful if you can explain me. > > - What confuses me, where does the "*disk driver*" comes into play? > > Thanks :-) > > > On Monday, November 4, 2019 at 5:43:24 PM UTC+1, The Lee-Man wrote: >> >> On Monday, November 4, 2019 at 2:49:08 AM UTC-8, Bobby wrote: >>> >>> Hi >>> >>> I have two virtual machines. One is a client and other is a sever (SAN). >>> I am using Wireshark to analyze the iSCSI protocols between them. >>> >>> Someone recommended me, in addition to a packet analyzer, I can also use >>> a packet generator. Any good packet generator for iSCSI client/server model? >>> >>> Thanks >>> >> >> Your question is not clear, but I'm *guessing* you are asking if you can >> use some sort of software to inject iSCSI packets into your client/server >> stream, e.g. so that you can simulate errors and see how your software >> handles them? >> >> If so, then the answer is no, there is nothing I know of. >> >> Such "bad command injection" can be done with fancy hardware analyzers. A >> good (expensive) network analyzer can (I believe) inject bad packets of any >> type.See https://www.firewalltechnical.com/packet-injection-tools/ >> >> It sound like none of this is directly related to open-iscsi, though. >> > > -- > You received this message because you are subscribed to the Google Groups > "open-iscsi" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to open-iscsi+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/open-iscsi/0c2592cf-ad61-4fe4-8006-63edabe4 > af7f%40googlegroups.com. -- You received this message because you are subscribed to the Google Groups "open-iscsi" group. To unsubscribe from this group and stop receiving emails from it, send an email to open-iscsi+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/open-iscsi/5DC3F334020000A100034E56%40gwsmtp.uni-regensburg.de.
