Help with mounting mhVTL library on MacOS / OS X

classic Classic list List threaded Threaded
10 messages Options
Reply | Threaded
Open this post in threaded view
|

Help with mounting mhVTL library on MacOS / OS X

ndroftheline
Hello all,

I'm very glad mhVTL exists, thank you! I'm trying to put together a couple of things to use it for, potentially to send encrypted backup streams to untrusted backup targets over the internet, but more importantly (for now) in my test lab for testing various workflows involving tape equipment at client sites.

Specifically, backup and data transfer workflows involving YoYotta, a MacOS-only application. I've virtualized MacOS and I have an iScsi initiator I'm testing (globalSAN) running there, which works with FreeNAS targets OK. I'm running mhvtl on a CentOS 7 VM, installed following this guide https://www.tech2max.com/mhvtl-on-centos-7/ and adding the UI here https://www.tech2max.com/mhvtl-gui/

I'm able to connect to these changers and drives from a Windows 10 VM and they show up in the Device Manager the way I expect. However when I connect from the MacOS VMs...nothing apperas to happen.

I searched the forums for MacOS and OSX keywords and unfortunately came up short, hoping that I might have missed something or that there's some other poor soul having to work with this stuff and can advise me.

Thanks kindly,

~ndr
Reply | Threaded
Open this post in threaded view
|

Re: Help with mounting mhVTL library on MacOS / OS X

Mark Harvey
Administrator
Thanks for the inquiry.

I am downloading globalSAN as I type this.. Although I have a Mac MBP myself - all dev is within a Linux VM.. I've not attempted Mac iSCSI initiator before. This should be fun.

I had a quick look over YoYotta and may have some bad news for you. YoYotta seems to be using LTFS.
Unfortunately at this point in time, mhVTL does not support LTFS. I see a request come in for it about every 6 mths or so i.e. not a big request. Given the amount of free time I have to spend on mhVTL, I can't say that it will be supported in any foreseeable time frame.
Regards from Australia
Mark Harvey
Reply | Threaded
Open this post in threaded view
|

Re: Help with mounting mhVTL library on MacOS / OS X

ndroftheline
Aw, a double-whammy. Unfortunately I seem to have bad news for you too: globalSAN may not support Tape targets(??) according to this: https://groups.google.com/forum/#!searchin/quadstor-vtl/mac$20os%7Csort:date/quadstor-vtl/orTxB3_ncG0/dCuCphde1RgJ

A user simply states, "the iSCSI Initiator from GlobalSAN does not support Tapes" - I have filed a ticket with their Support asking for clarification but that certainly seems to match with my understanding.

I'm keen to learn enough about how these go together to at least get : 1. why it's even possible for an iSCSI initiator to not support a certain type of drive and/or 2. why LTFS requires special support by the tape drive

Any input you might have on how I can achieve this would be most welcome (:
Reply | Threaded
Open this post in threaded view
|

Re: Help with mounting mhVTL library on MacOS / OS X

Mark Harvey
Administrator
2. why LTFS requires special support by the tape drive
LTFS was an extension to the LTO format introduced around the LTO-5 days and requires the tape & drive to support multiple partitions.
While support for more than one partition shouldn't be hard to implement - the lack of software to test support for LTFS, the lack of spare time and low number of requests have meant that it has never really made it into something usable.

QuadStor provide a free VTL (wasn't around when I started this project) - it may have LTFS support.
Regards from Australia
Mark Harvey
Reply | Threaded
Open this post in threaded view
|

Re: Help with mounting mhVTL library on MacOS / OS X

ndroftheline
I can introduce you to Martin, the head of YoYotta, who said he might be willing to organize an "extended trial" for me to test various scenarios in my lab for clients. I work primarily with entertainment industry clientele so a program like YoYotta, which is simple and easy to use, is really valuable for them. That way you'd have a compatible bit of software that speaks LTFS to test with, potentially at least one fo the three hurdles down (: 

I found an open source iSCSI initiator on github, https://github.com/iscsi-osx/iSCSIInitiator , which is quite a stretch honestly to disable SIP just to install it, but in my VMs is OK - I discovered I can't run it in Mojave so I'm now installing High Sierra to try that. I'll try to let you know if I discover a way to actually initiate an iSCSI link to a tape drive, and how I did it, so you can potentially move forward on this route. 

Thank you again for spending your spare time doing this, and being so responsive to queries. 

~Micah

On Fri, Feb 28, 2020 at 2:56 PM Mark Harvey [via mhVTL - A Linux Virtual Tape Library] <[hidden email]> wrote:
2. why LTFS requires special support by the tape drive
LTFS was an extension to the LTO format introduced around the LTO-5 days and requires the tape & drive to support multiple partitions.
While support for more than one partition shouldn't be hard to implement - the lack of software to test support for LTFS, the lack of spare time and low number of requests have meant that it has never really made it into something usable.

QuadStor provide a free VTL (wasn't around when I started this project) - it may have LTFS support.
Regards from Australia
Mark Harvey



To unsubscribe from Help with mounting mhVTL library on MacOS / OS X, click here.
NAML
Reply | Threaded
Open this post in threaded view
|

Re: Help with mounting mhVTL library on MacOS / OS X

Mark Harvey
Administrator
In reply to this post by Mark Harvey
One more thing regarding LTFS and VTL.

LTFS is an attempt to make a streaming device emulate a block device. i.e. Make a tape (sequential access) behave like a file system (designed for random access).

A VTL is an attempt to make a block device emulate a streaming device. i.e. Make a file system (random access) look like tape (sequential access).

Hence, emulating LTFS in a VTL - you end up where you started. Why not just write to the file system to begin with !
Regards from Australia
Mark Harvey
Reply | Threaded
Open this post in threaded view
|

Re: Help with mounting mhVTL library on MacOS / OS X

ndroftheline
Ha, that's a very valid point. And I suspect that logical conflict has added to your lack of focus on LTFS support - why would anybody do this anyway. I have to work with this because it's what the client is doing in their environment, and I want to be able to model changes in my lab without having any actual tape equipment. I'm not planning on using workflow to actually store importan data - only for modeling and testing data workflows. 

On Fri, Feb 28, 2020 at 3:08 PM Mark Harvey [via mhVTL - A Linux Virtual Tape Library] <[hidden email]> wrote:
One more thing regarding LTFS and VTL.

LTFS is an attempt to make a streaming device emulate a block device. i.e. Make a tape (sequential access) behave like a file system (designed for random access).

A VTL is an attempt to make a block device emulate a streaming device. i.e. Make a file system (random access) look like tape (sequential access).

Hence, emulating LTFS in a VTL - you end up where you started. Why not just write to the file system to begin with !
Regards from Australia
Mark Harvey



To unsubscribe from Help with mounting mhVTL library on MacOS / OS X, click here.
NAML
Reply | Threaded
Open this post in threaded view
|

Re: Help with mounting mhVTL library on MacOS / OS X

ndroftheline
In reply to this post by ndroftheline
Heya Mark,

Just wanted to report some initial success with mounting Tape drives (from both quadstorVTL and mhVTL) using Daemon Tools' iSCSI initiator.

https://www.daemon-tools.cc/products/dtMacLite

(Assuming free version) Once you install and authorize, launch and click the Remote Devices entry under the iSCSI group in the left pane; that will take you to a Customize page which allows you to edit the licensed features, enable the trial of the iSCSI function and click the Customize button in the top right to toggle it back away. Then right-click in the field and click Add. That will discover your iSCSI portals, which you can add, and then right-click a target and Connect.

It is by far and away the easiest and most complete iSCSI initiator I've found so far. It's also relatively affordable, which is amazing. With QuadstorVTL running an IBM System Storage TS3100 with a IBM 3580 Ultrium8 drive and 3580u8L8 vCart, I'm able to get up to the point of actually initiating an ltfs mount...at which point I get a bunch of SCSI errors which I'm opening a forum post there for, and will continue there.

Just wanted to share my experience so far, in case you wanted to continue on with MacOS and LTFS (:

Thanks again and regards from New Zealand!
Reply | Threaded
Open this post in threaded view
|

Re: Help with mounting mhVTL library on MacOS / OS X

ndroftheline
Oh, critical pieces of information: I'm using IBM SDE 2.4.12 tooling for LTFS which I downloaded from IBM (registerwall) and the osxfuse provided by homebrew.
Reply | Threaded
Open this post in threaded view
|

Re: Help with mounting mhVTL library on MacOS / OS X

Tim Jones
Because of the way that MHVTL has been developed, it will not support LTFS - nor should it as Mark has described.  Because of the way that Yoyatta ID is developed, it can ONLY write to tape using the LTFS layer and can't use the VTL layer that MHVTL provides since it doesn't have any form of tape I/O logic built in.  This is not an experiment that you will be able to resolve from either end.

Tim