Hello, I have an old HP D6000 enclosure that I'm repurposing for Truenas. It has QTY 70 4TB drives. I'm going into a DL380 Gen 8 with dual LSI 9200-8e HBAs. The Truenas manual says that a "Multipath" option in the menu will be enabled when multipath exists. I don't have that option.
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Is multipath setup correctly and enabled?
- Thread starter ro345
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Perhaps you can share the page of the manual you're looking at. I don't see it:
My bad. It looks like I didn't realize that I was reading the Freenas 11 manual. The Truenas manual doesn't mention this (even though I swear that I saw it show in the Truenas UI at some point). My question still stands though, if it says "Optimal" is multipath correct and is Truenas using it? Thanks!
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The 11.x manual isn't applicable for 12.x or 13.x. Multipath UI support didn't get carried forward for 12.x or 13.x, because it just ended up confusing users. Indeed, there have been some nasty bugs found in the 12.x UI, which displayed passive members of multipaths as available for constructing pool VDEVs. See https://www.truenas.com/community/t...-zpool-in-creating-another.97421/#post-672712.
For your own sanity, I suggest you create a LOADER-type tunable in System->Tunables with variable geom_multipath_load and value NO, and then rebooting to disable multipath.
Edited: I erred in the value of the tunable the first time.
For your own sanity, I suggest you create a LOADER-type tunable in System->Tunables with variable geom_multipath_load and value NO, and then rebooting to disable multipath.
Edited: I erred in the value of the tunable the first time.
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No, what I said is the UI is not useful for managing multipath in 12.x or 13.x. If you're willing to manage your pool entirely through CLI, multipath is usable in 12.x or 13.x. It's just that I doubt you've got the knowledge nor experience to do this safely.
In fact, I doubt you've got a use case that would justify the headaches involved with multipath. Unless you need 5x 9s uptime, and can't tolerate any hiccup in iSCSI serving volumes (like satellite telemetry), you don't really need multipath. Even then, iSCSI can achieve similar reliability with Ethernet multipath, which is much easier to administer and understand.
If you're just messing around to learn, then by all means play around with multipath. Just be prepared to have to rebuild your pool when it gets toasted.
Also, 11.x is end of life.
In fact, I doubt you've got a use case that would justify the headaches involved with multipath. Unless you need 5x 9s uptime, and can't tolerate any hiccup in iSCSI serving volumes (like satellite telemetry), you don't really need multipath. Even then, iSCSI can achieve similar reliability with Ethernet multipath, which is much easier to administer and understand.
If you're just messing around to learn, then by all means play around with multipath. Just be prepared to have to rebuild your pool when it gets toasted.
Also, 11.x is end of life.
Your Multipath statement is concerning..... Is this true? other sources please?
jgreco
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Three of @Samuel Tai 's four paragraphs contain the word "Multipath". Perhaps you should clarify which statement it is you mean when you say "Multipath statement".
What
What Samuel is saying is essentially that MP is useless in the GUI. Which appears to be correct from experience with Truenas CORE.
jgreco
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I don't need you to interpret what Samuel is saying. You said something ambiguous and I wondered if you meant something in particular.
I understand the root problem, which is that you're wanting to use a feature that isn't really intended for your use, but isn't explicitly disabled. The multipath stuff is really there to support TrueNAS Enterprise, where an iXsystems support engineer would be connecting directly to the server via ssh and would be setting it up and managing it that way. Trying to do this without the requisite knowledge can definitely be a shoot-yerself-in-the-foot misadventure, and the fact that there isn't a full set of GUI management tools for it is not surprising given the potential level of complexity.
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The 'Multipaths' tab will only appear once you have made a pool out of one or more multipath devices
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Multipath works fine in TrueNAS 13 but it is a little different than in previous versions so you do need to know what youre doing.
For example disks are assigned their multipath names at boot via the gmultipath command but historically if disks were added/replaced into a live system they would also recieve a multipath name after a few seconds however this is no longer the case. By default multipath names are now only assigned and updated in the UI at boot. You can however instigate a gmultipath taste using the following command:
/usr/local/bin/midclt call disk.multipath_sync
This command is crucial when you are performing disk replacements on a live system otherwise you would have to reboot your server everytime you wanted to replace a disk.
There are a few other changes in the implementation but thats outside the scope of this thread and perhaps one for onther day when I have more time.
Good luck
For example disks are assigned their multipath names at boot via the gmultipath command but historically if disks were added/replaced into a live system they would also recieve a multipath name after a few seconds however this is no longer the case. By default multipath names are now only assigned and updated in the UI at boot. You can however instigate a gmultipath taste using the following command:
/usr/local/bin/midclt call disk.multipath_sync
This command is crucial when you are performing disk replacements on a live system otherwise you would have to reboot your server everytime you wanted to replace a disk.
There are a few other changes in the implementation but thats outside the scope of this thread and perhaps one for onther day when I have more time.
Good luck
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