Thanks for the suggestions. Everything you suggested checked out. Speed is definitely 1000Mb/s, no errors, and hard drive speed is plenty quick. Also, the tape drive itself isn't iSCSI, the enclosure is (Spectra Logic NAStape 250). Any other suggestions?
On Jun 18, 8:07 pm, Sparqz <[EMAIL PROTECTED]> wrote: > I must have really dark sunglasses on, because I've never seen an > iSCSI tape drive before? > > Anyhow, I don't think your MTU (lack of jumbo frames) is the problem, > I can easily get 50MB/s sustained transfers over a gigabit network. > > First I would confirm that the path between your linux iSCSI server > and your tape drive is running a the full wire speed (gigabit). > > Assuming eth0 is the ethernet port you use for iSCSI traffic type > "ethtool eth0" and make sure you see: > Speed: 1000Mb/s > Duplex: Full > amongst the garbage that fills the screen. > > Also, you can type "ifconfig eth0" and you should see something like: > RX packets:62361505 errors:0 dropped:0 overruns:0 frame:0 > TX packets:110583510 errors:0 dropped:0 overruns:0 carrier:0 > make sure that there are no errors (or dropped packets, overruns or > framing errors) > > I wouldn't worry too much about the TCP Checksum messages that > wireshark shows (usually it's because another part of the system > checks these checksums and mangles them in the process) > > Finally, can your local disk support 30MB/s ? might be worth > installing something like iozone or bonnie++ to make sure your disk > can be read and written to at 30MB/s. > > Hope this helps! > > On Jun 17, 6:27 am, Michael <[EMAIL PROTECTED]> wrote: > > > > > Hi all, > > > I've been using open-iscsi to set up an IBM Ultrium LTO-4 tape drive. > > I can connect and transfer files and everything, but the maximum read > > or write speed I can get is like 16MB/s by tweaking the block size. I > > am on a gigabit network, which the tape drive supports. The drive > > specifications rate it at 30MB/s so I'm off by 50%. Does anyone know > > what I can do to get the speed up to scratch? I'm pretty much a Linux/ > > network newbie so I no idea if its an open-iscsi tweak or a network > > tweak that I could possibly do. Also, I checked and my network card > > only supports MTU=1500, if that matters.- Hide quoted text - > > - Show quoted text - --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "open-iscsi" group. To post to this group, send email to email@example.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 -~----------~----~----~----~------~----~------~--~---