Hi, I run backups with Amanda and anq Onstream ADR 50e tape (external version, SCSI LVD) since about a year without any visible problems.
I know about the "mt -f /dev/nst0 stoptions scsi2log" trick for this drive and while I wasn't able to find any explanation what this command actually does, I use it and my backups work fine. :-) Now I had to recover some files and had problems. While searching the web for help, I found the following page: http://www.linuxtapecert.org/adr50_notes.html It states: --- cut --- Changing Tape Block Size Many SCSI tape drives provide the ability to utilize various tape block sizes. The OnStream ADR 50 only supports fixed, 512 byte blocks in its current firmware level. We have reports from users that attempting to change the blocksize can cause the device to hang to the point of requiring a power cycle of the drive to clear the state. --- cut --- In the amanda(1) page is stated: --- cut --- blocksize "int" Default: -32 kbytes. How much data will be written in each tape record. [...] The minimum absolute blocksize value is 32 KBytes. The maximum absolute blocksize value is 4 MBytes. --- cut --- Now I'm confused. Does this mean, that my backups just worked by chance? That Amanda should't be able to either read or write on the tape? mt reports (after rewind): % mt -f /dev/nst0 status SCSI 2 tape drive: File number=0, block number=0, partition=0. Tape block size 512 bytes. Density code 0x0 (default). Soft error count since last status=0 General status bits on (41010000): BOT ONLINE IM_REP_EN I have no problems changing the block size by issueing % mt -f /dev/nst0 setblk 0 (variable) % mt -f /dev/nst0 setblk 32768 but I don't know whether this change actually happens on the driver or only in the driver. Setting the block size to "0" or "32768" kills every attempt to read a tape that was written with block size = 512. Uhm. Help. Can I issue "blocksize = -512" in amanda.conf to adjust for the tape drive? Would this help? Or is it simply not possible (see above)? I'm using the following tape type: --- cut --- define tapetype ADR50 { comment "Onstream ADR 50" length 21056 mbytes filemark 0 kbytes speed 1579 kps } --- cut --- Regards Henning -- Dipl.-Inf. (Univ.) Henning P. Schmiedehausen -- Geschaeftsfuehrer INTERMETA - Gesellschaft fuer Mehrwertdienste mbH [EMAIL PROTECTED] Am Schwabachgrund 22 Fon.: 09131 / 50654-0 [EMAIL PROTECTED] D-91054 Buckenhof Fax.: 09131 / 50654-20
