ISCSI: cannot view S.M.A.R.T data from client

[AlanOne]

Hello,

I didn't find much on the web, so I ask here.
I have setup truenas as ISCSI target and have the initiator on a windows machine. I have tried numerous hdd utilities, but I cannot get the s.m.a.r.t data. Is it by design of the ISCSI protocol or I miss something?

 

[WI_Hedgehog]

If I understand what you're trying to do, I think the answer is: iSCSI is a virtual device, it doesn't have S.M.A.R.T. data.

The hard drives themselves are real devices that have S.M.A.R.T. data which can be polled via smartctl by the machine with the drives in it.

 

[AlanOne]

I think you are correct. Dumb question then; I never thought of iscsi as virtual device, as it felt more like a pass-through to actual hardware. Side question, why truenas does not have a s.m.a.r.t status display in webgui like the usual table that the numerous win utilities have?

 

[joeschmuck]

Side question, why truenas does not have a s.m.a.r.t status display in webgui like the usual table that the numerous win utilities have?

Good question. Many of us would like a more comprehensive SMART report other than Temp and SMART Short/Extended test results. It very well could be due to the complexity of the manufacturers not using a defined standard to report items in the same format. The script I manage makes a lot of exceptions for different drives/manufacturers. Even a single manufacturer will often use different messages to communicate a value. One recent example is an Intel SSD reported Wear Level having 100 being the best value and 0 being very bad. The other day I got data from another model Intel SSD and the Wear Level was exactly the opposite. So updating the script fixed it now. My first fix was a quick patch, the next fix is a real long term fix.

My point, it may not be worth it to iXsystem to include that data. Keep in mind that they are selling systems to big customers and as long as it works, they are happy. We get to write scripts/code to fill the gaps. If you want to see my script, it's linked below.

 

[AlanOne]

Very interesting! On the othe hand, in windows, one might use a not up-to-date utility and get "wrong" results; unless there is some other factors in reporting. New side question, what about AoE? Will it report s.m.a.r.t to client? (afaik truenas does not have official support for AoE yet)

 

[jgreco]

Very interesting! On the othe hand, in windows, one might use a not up-to-date utility and get "wrong" results; unless there is some other factors in reporting. New side question, what about AoE? Will it report s.m.a.r.t to client? (afaik truenas does not have official support for AoE yet)

ATA over Ethernet has been effectively dead for nearly two decades. TrueNAS is never going to have support for AoE, and most likely nothing else will either.

You seem to be confused about what a NAS is. It is not a device that offers raw block storage like individual ATA, SATA, or SAS devices over the network. The NAS maintains its own filesystem, a ZFS pool (or pools) in this case, and provides storage views out of that. You cannot meaningfully report SMART over the network for an abstraction such as a ZFS pool, which is a conglomeration of various types of storage ranging from system memory on down to hard disk. When you ask for SMART data of an AoE or iSCSI 50TB virtual device that is made up of dozens of 2TB SAS HDD's (which may not even have SMART), what exactly do you expect the system to return to the client?

This circles back around to @WI_Hedgehog 's comment above.

 

[AlanOne]

I never asked for s.m.a.r.t for an abstraction like zfs, or any raid array (its obvious). In fact I am not using zfs at all, just iscsi with each disk seperate; does it autmatically mean that I don't understand what a nas is or I sould not use truenas as I use it? To be more precise and correct, my setup qualifies as SAN. I asked about AoE because it seems to be more close to bare metal than iscsi, but I don't have any experience with this (perhaps you guys might have). Whether aoe is abandoned or not , it has it's pros over iscsi.

 

[Patrick M. Hausen]

So you don't use TrueNAS? In TrueNAS iSCSI LUNs are ZFS volumes. Nothing else is supported. This gives you features like snapshots, rollback, replication on the storage appliance (NAS) without the iSCSI initiator needing to know.

 

[AlanOne]

No, I use truenas :/ And no, I have not setup any zfs volume.

 

[Patrick M. Hausen]

So how did you create your iSCSI LUNs?

 

[AlanOne]

create portal

add target -> assign previous portal

create extend (add hdd device)

assign target -> previous target & previous extend

 

[Patrick M. Hausen]

So today I (and possibly more regulars) learned something from you. I wasn't aware TrueNAS supports raw disk devices as iSCSI LUNs.

Thanks.

 

[AlanOne]

Glad that it was usefull! I had to recheck it (maybe I was creating a zfs pool without knowing since I am noob at whatever-linux) and I just made a fresh test install. It just works, and I don't see any reason why it shouldn't (of course this way you don't gain the bit-rot countermeasures that zfs is providing).

And for the sake of this thread, even with "wrong" reports as joeschmuck said, viewing the s.m.a.r.t status PER DISK™® in gui would be usefull!

 

[HoneyBadger]

So today I (and possibly more regulars) learned something from you. I wasn't aware TrueNAS supports raw disk devices as iSCSI LUNs.

Thanks.

We also support file-backed iSCSI extents; however, ZVOLs are the preferred option.