Hi All,

I have a redhat box which was zoned up to a VTL (singular) on two fabrics. For that reason, there are two /dev/sg* devices for this VTL. These two devices share the same device serial number.

Within my backup application on this server (TSM), you can only point the device path for that VTL to one of these two devices, but I'd like the O/S to use them both. Is there some way at the O/S level in redhat to link those two devices together?

Sincere thanks,
C.J.

This is what Linux multipath does - gives you a single device based on multiple paths to the device. Each path to a device would use standard scsi disk naming (/dev/sd*) but the multipath device uses a name (e.g. if using "friendly names") like /dev/mapper/mpath* and you set your processes to use that device instead of any of the underlying /dev/sd* devices. If one of the underlying paths goes away your processes still work because they can get to the disk via the other sd path.

If you do a web search for "multipath tutorial" you'll find various hits like this one:
http://thegeekdiary.com/beginners-gu...-multipathing/

Of course on rereading it appears you're talking about tape rather than disk and I've not done anything like that with tape. For our tape libraries we only have one path to tape for each drive and were told multipathing isn't possible. For your VTL I don't know the answer. I did find hits talking about multipathing for IBM and TSM:
https://adsm.org/forum/index.php?thr...ltipath.16459/ (For AIX?)
https://www.ibm.com/support/knowledg...4multipath.htm

Another hit I found mentions tape for standard Linux multipathing (device mapper multipath) but has no examples other than the disk multipathing I'm familiar with.