Hi George, The udev config files used by Lin_tape allow for tieing specific device names to attributes of the tape drives like their serial number, or perhaps LUN number.
I was a bit surprised to see that all EMC EDL devices assigned to a given path are presented all on the same WWNN, differing only by LUN. Multiple connections to a VTL is common. From what I've seen, only one control path is typically enabled, and this takes LUN 0. LUN 0 is not reserved on any other paths. So moving a control device from one path to another causes all the LUNS to change. I don't know what incentive Tivoli has to make Lin_tape behave better with EDL pretending (badly) to be a 3584, but it does look like they've at least left a breadcrumb trail to allow us to do it ourselves. Does you mechanism for resolving the SCSI reserve problem cover the case where the TSM instances are running on different machines? Thanks, [RC] On Oct 18, 2010, at 11:26 AM, giblackwood <tsm-fo...@backupcentral.com> wrote: Mr Forray, I know a lot about this problem you are dealing with. My name is George Blackwood. I was a Systems Engineer with IBM for 30 years. Among other things, I was a SAN, tape, and TSM specialist. I have been retired for 2 years, 1 month. I have my own consulting business doing what I did when I was an IBMer. When Linux is rebooted (RedHat, SLES, whatever), it will scan and re-discover its SCSI and FCP (Fibre Channel Protocol) tape resources without regard of what it knew about those same devices before the reboot (this is not the case with some UNIX systems). So, unless you have one changer and one tape drive, you have no guarantee that the Linux device numbers will be the same after reboot. So, chances are IBMtape0 will be IBMtape20 the next time you reboot. IBM's answer is to set "SANDISCOVERY ON". This works sometimes for a small number of drives (under 20), and will sometimes work for more. But after 18 months of being in and out of IBM PMRs and "CritSits", I have given up on sandiscovery to fix this issue. I wrote a BASH script to fix this issue. A current customer of mine has 8 RedHat Linux servers sharing 12 TSM instances (we can move them around as need be). Two instances are Library Managers. All instances have access to 4 EMC EDLs. Each EDL has 80 drives. So that comes to 3890 drives paths, plus 4 Library paths to maintain. The script I wrote discovers what TSM instances (Library Servers and Clients) are running on a given Linux server that has just been rebooted. It compensates for any drives that may be mounted, or any Libraries that are in use, and re-defines all the Library and drive paths for any TSM instance on a given Linux server. So if one of the 8 servers needs to be rebooted, the script is run on that server after reboot. There is no need to unmount and quiesce Libraries. The only requirement is the Library Managers must be up. The script will also find what drives are in a SCSI reserve "lock out". And, it is safe to be run during full production time. I can give you a few pointers to write a similar script (for free), or for a fee, write it for you. I guarantee my work. George Blackwood Blackwood Data Protection Consulting, LLC 785-218-9961 georgeblackw...@sunflower.com +---------------------------------------------------------------------- |This was sent by georgeblackw...@sunflower.com via Backup Central. |Forward SPAM to ab...@backupcentral.com. +----------------------------------------------------------------------