Overtaxed

I have a active-backup (1) bond setup on my UnRAID (6.9.2) server between a 10G and 1G adapter. I want the 10G adapter, if it has a link, to always be the active partner. Was seeing a whole bunch of traffic out of my 1G switch from UnRAID and logged in to find this: root@unraid:/proc/net/bonding# cat bond0 Ethernet Channel Bonding Driver: v5.10.28-Unraid Bonding Mode: fault-tolerance (active-backup) Primary Slave: None Currently Active Slave: eth1 MII Status: up MII Polling Interval (ms): 100 Up Delay (ms): 0 Down Delay (ms): 0 Peer Notification Delay (ms): 0 Slave Interface: eth0 MII Status: up Speed: 10000 Mbps Duplex: full Link Failure Count: 1 Permanent HW addr: 90:e2:ba:2e:ee:bc Slave queue ID: 0 Slave Interface: eth1 MII Status: up Speed: 1000 Mbps Duplex: full Link Failure Count: 2 Permanent HW addr: 00:d8:61:37:1e:13 Slave queue ID: 0 I bounced the interface on eth1 and, as expected, UnRAID failed back to the 10G link and everything looks good: root@unraid:/proc/net/bonding# cat bond0 Ethernet Channel Bonding Driver: v5.10.28-Unraid Bonding Mode: fault-tolerance (active-backup) Primary Slave: None Currently Active Slave: eth0 MII Status: up MII Polling Interval (ms): 100 Up Delay (ms): 0 Down Delay (ms): 0 Peer Notification Delay (ms): 0 Slave Interface: eth0 MII Status: up Speed: 10000 Mbps Duplex: full Link Failure Count: 1 Permanent HW addr: 90:e2:ba:2e:ee:bc Slave queue ID: 0 Slave Interface: eth1 MII Status: down Speed: Unknown Duplex: Unknown Link Failure Count: 3 Permanent HW addr: 00:d8:61:37:1e:13 Slave queue ID: 0 Question is, how to I make it so that if the 10G NIC has a link, it will use that as the primary at all times? In the GUI, bonding members of bond0 show as "eth0, eth1". I set eth0 to be the 10G NIC, I thought UnRAID always preferred the lower number, so I set eth0 to the 10G NIC using "Interface Rules".

Yes, client was online and connected. It's a real disk (NVME unassigned device). Do you know what that error means? I was thinking maybe MTU on the network?

Well, something went wrong last night and I'm trying to figure out what it is. UnRAID went down hard; just froze. I didn't see the console, I just kicked off a reboot and I see a lot of these messages in syslog. Not sure if this has anything to do with iSCSI or not? I've never had UnRAID crash before, so I may be making an association that doesn't exist, I've added a lot to this server, NVME, unassigned devices, a 10Gb NIC.. No way can I point at iSCSI, but since this thread is already rolling, figured I'd start here and see if this might be a place to look: Apr 8 08:41:33 unraid kernel: WRITE_SAME sectors: 2048 exceeds max_write_same_len: 1025

Upgrade to 6.9.1 went without a hitch. I was living dangerously and left a server up on the ESX host to see what would happen during the reboot. Froze when UnRAID went down (as expected) and then recovered gracefully as soon as it came back. No loss of state, no reboot on the server, just a freeze and recovery, exactly what VMware should do when it "loses" a LUN. Very nice!

See 6.9.1 is out, any specific considerations/concerns about doing an upgrade with the great iSCSI work you guys have done? Just want to make sure I don't blow it up, obviously spin down the VMs and I'll need a reboot, just want to make sure I'm not going to lose the LUNs or iSCSI configuration. BTW, in case anyone is keeping track, running perfectly now for ~2 weeks. Not a hiccup. vMotion works great, and I recently moved everything to 10G, it's rocket fast coming off the NVME in my UnRAID server to the VMware hosts via iSCSI. Works fantastic! Thank you again for the great work on this!

So, doing a little more testing, things are still working very well. Not a single blip to my ESX servers, and, even better, I've rebooted UnRAID while a VM was up, using iSCSI and it recovered from that gracefully (VM froze until storage came back, which is what it should do). One thing I've noticed, it appears that the iSCSI traffic all runs on CPU 0. Here's what I'm seeing running an FIO from the VM using an iSCSI disk; 93% utilized on CPU0, everything else pretty much flatlined. Now, the good news, this is pushing 3-4Gb/s of traffic down that iSCSI pipe, not too shabby! Is iSCSI bound to dom0 or restricted from the rest of CPUs (either by design, or perhaps by something I did)?

Well, the support I'm getting here is lightyears beyond what I get for commercial software, so, while it might be a good idea, you guys are killing it. And thank you for that and this contribution to the UnRAID community! Even if it breaks and takes all the VMs with it, you guys have shown it's doable and I'm sure this functionality will wind up mainstream in the future, that's a huge step forward for all of us idiots doing stuff like running ESX clusters at home.

Thanks Simon, looks like that's the one: 0x4d (LOG SENSE), presumably because the Solaris initiator is trying to check for disk errors. Fortunately we are already doing that on the iSCSI backends (well, usually). Not sure exactly how or why ESX is trying to 'check for errors', but I suspect that's what it is. Good news though, despite those errors/warning messages, going into 24 hours with rock solid connection via iSCSI. No drops, vMotion is working fine, VM itself has nothing troubling reported at all. Working very well!

Getting a strange message in syslog, any ideas on this one? unraid kernel: iSCSI/iqn.1998-01.com.vmware:esx1-5b059529: Unsupported SCSI Opcode 0x4d, sending CHECK_CONDITION.

Honestly, I think your plug-in looks great! The thing I found confusing is what needs to be built in/added to get it working (because this thread goes back to a time before it was in the kernel). It was really dead simple, install 6.9, install plug in, configure, done. That said, I used to admin a large (Netapp) based iSCSI environment, so.. I'm pretty familiar with how all the pieces fit together, target/initiator, LUN, mapping, etc. Certainly would have been harder if I didn't have that experience. I'm running the iSCSI LUN to VMware, and, when I tried this with an RC, I had some issues with disconnects. File based LUN on my cache pool (2 drives) would get random disconnects/freeze ups. I'll see it I have the same issue this time, but, so far, it's rock solid and fast.

Seems to be working, and was pretty darn simple (as said, just install the plugin and configure). I'm sure people who want it will figure it out.

Now that 6.9 is out in the wild, any chance we can get a walkthrough of setting up iSCSI on it? I did play with iSCSI using an RC, but I saw a few RC's back that iSCSI was now in the kernel, so I'm not sure what actually needs to be done with your plugin vs what's native in UnRAID now. Thank you again, awesome upgrade and add to the community here!

Wondering, what happens if you create a mirror cache with an NVME and physical hard drive in it (both 2TB)? Is btrfs smart enough to realize that one drive is much faster and send the majority of the reads that way, or does it just balance between X number of drives, sending 1/X the IO to each drive? I'd like to see the activity on the physical drive be basically only writes and have all the reads come off the NVME because it's so much faster.

I'd love to have this functionality too. I have found it's just not reliable enough, dropped datastores and locked up VMs. No idea if this is VMware's problem or UnRAIDs, but whatever it is, it's not very usable as it sits today for me. I'd be fine with iSCSI or NFS. My concern isn't really speed, but I'd be storing my VMFS/NFS partitions on an SSD mirror cache pool, so I don't really need the speed of multi-disk, a single drive will produce plenty of IOPS for what I need. Any plans/progress on looking at this use case?

Unbalancing appdata and system shares away from the user (parity) drives as we speak. I'll update with success/failure after I've had a little time to test.