On Saturday, October 27, 2018 at 8:30:52 AM UTC-7, Ben Klein wrote: > > Hi, > > I've been trying to get a DVD-ROM drive working over iSCSI. I'm using > targetcli on the target and iscsiadm/iscsi_discovery on the initiator. > > Target is running 4.18.16 unpatched from kernel.org, with AMD64 > Devuan/Debian stable userland. 10 year old Core 2 Duo CPU. > > Initiator is running 4.18.15 unpatched from kernel.org with AMD64 > Devuan/Debian unstable userland. Ryzen 7 CPU. > > Using pSCSI backend on /dev/sr0 triggers a memory leak that consumes all > 5GB of system RAM on the target in a matter of seconds after attempting a > read (I've been testing with "file -s") on the initiator side. It doesn't > go into swap memory. > > I tested pSCSI and IBLOCK backends on a WD Green SSD, and found IBLOCK > works fine (I was able to run mkfs.ext4 from the initiator without any > memory leak on the target), but pSCSI still seems to trigger a memory leak, > albeit a lot slower than with the DVD-ROM. I suspect udev might have > something to do with this, as tries to read the volume label off optical > discs on insertion. > > I have attached my targetcli output, and have configured my target-side > kernel for coredumping and debugging. If someone can talk me through what > to look for, I can poke around in the 5GB vmcore that gets produced by > kdump. > > Please let me know if there's any other information I can provide. > > Thanks, > Ben Klein >
You would probably get more useful advise on the [email protected] mailing list, since we mainly have initiator expertise here. They might have even seen and fixed this issue. Never the less, you can try debugging the target driver. I believe the target code uses dynamic debugging, which means you can enable the debugging at run time, using the path /sys/kernel/debug/dynamic_debug/control. You can enable debug printing for one or more lines, for a function, for a module, etc. Pretty flexible. But it really helps to look at the code to see what is being reported on (IMHO). I have recently used a similar setup to test tape over iscsi using the pscsi backend, and I did not notice a memory leak like the one you're reporting, if that helps. -- 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 [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/open-iscsi. For more options, visit https://groups.google.com/d/optout.
