In most cases you can use a LTO drive from a library as a standalone drive. As tapelibraryfixer stated you might get some unexpected behavior as the drive might be looking for the library.
Please let us know if you have any other questions.
@tapelibraryfixer, good day, I have a SAS HH drive out of a library that we intend to repurpose as standalone and get exactly the "Error E" in the SCD, after a boot sequence that counts down from 8 to 0. The drive has two small connectors besides the SAS/power connector. One of them was attached to the caddy (I believe it is the RS-422 connector). There's yet another one which my google research has led me to believe it might be an ethernet service port. Is there any way to connect to this drive via RS422 or Ethernet and set it to standalone mode so that it doesn't throw a fault because of looking for and not getting a response from the automation interface? Would such an update be doable, for example, via ITDT? Thanks
The only way to turn off "library mode (E)" is through the serial port, as "library mode" turns off the FC/SAS connection until the library decides to activate it.
i think the serial port maybe password protected not sure.
From your answer there, I got to know that the way to go was to connect to this pesky drive via serial port.
After a lot of googling, manual-reading, pinout guessing, and serial terminal fiddling I was finally able to set the drive to standalone mode ie. turning on "Automatic Drive Online". This means the drive will turn on its SCSI/SAS/FC bus without the need of being told to do so by the library via serial.
The procedure I did could be the topic of a howto/writeup of some sort if anyone is interested. I took care to take a few photos where relevant.
The tape drive can be use as standalone: it will be detected as a tape device in /dev/tape/by-uuid/ that will link to a device like /dev/nst0 on linux.
Then you could issue tar or dd on this device directly (tar is historicaly made for this ...).
For example, you can issue a:
tar cvf /dev/nst0 myfolder1
tar cvf /dev/nst0 myfolder2
Each write will end with a "eof" that will allow to read it by "block". Remember that, on a tape, you will not have any partition or FAT (File Allocation Table). You have to remember where you put your archive to retrieve it.
For example, when you will need the folder "myfolder2", you will have to issue thoose commands:
mt -f /dev/nst0 rewind # ... rewind the tape
mt -f /dev/nst0 fsf 1 # Fast Forward: jump 1 "file" on the tape, so you the tape drive be on the 2nd file
tar xvf /dev/nst0 myoutputfolder # untar the archive of myfolder2 to the output folder myoutputfolder
Using it with a software like Bacula is more easy that doing thing by hand.
To know: in a tape library, the drive communicates with the tape library, so it will relay actions to it. For example, when you want to unload the tape to a given slot, your systems sends an order to the drive than will send it to the tape library using a dedicated bus (RS422). The drives ejects the tape, and the tape library takes it to store it in a given slot. From a Linux point of view, when a drive is connected to a tape library, it creates a device such as /dev/ng0 that will allow you to issue commands such as : mtx -f /dev/sg0 70 0 (that would unload the tape in drive 0 to the storage slot 70).
Of course, if you use a drive without a tape library, you will not have this /dev/sg0 device. For Bacula, you can use a wrapper that will allow the softare to call defined scripts to be called instead of mtx. When you don't have a library, such a script can consist in sending a mail to a human asking it to take the ejected cartridge and insert another one instead.
Hi all - I acknowledge this is a fairly old thread to resurrect, but I would absolutely be interested in knowing the steps in converting a drive that was in a library to standalone mode. I'd dearly love to see those pictures or the writeup of what to do - thank you very much in advance for your generous sharing of knowledge!
DELL-Sam L
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Posted February 5th, 2018 06:00
Hello,
In most cases you can use a LTO drive from a library as a standalone drive. As tapelibraryfixer stated you might get some unexpected behavior as the drive might be looking for the library.
Please let us know if you have any other questions.