Re: SCSI tape backup for 9406-170

Hello,

Am 16.11.2023 um 00:24 schrieb hush <system@xxxxxxxxx>:

i am getting back to work on my 170 lately and have been trying to identify if there are any tape backup options

Here are my findings: https://try-as400.pocnet.net/wiki/Tape_Drives_on_old_AS/400

I'm using a HP DDS3 drive on a daily base in my 150, with DD3 tapes for monthly "Save 21", and 31 90m (DDS1) tapes for daily differentials. Works like a charm and is much less noisy than QIC. Drives and cartridges are still comparatively cheap to obtain. My recommendation. 👍

One thing to consider is the data transfer rate. Because of the very nature of OS/400, data being saved is read from DASD through (demand) paging — being at the very core of the OS foundation. This is highly optimized for low latency (to quickly bring a record from disk to the screen) but isn't exactly a well-performer when it comes down to sustained "high" data transfer rates. This is contrary to many tape drives enduring the least war and tear when fed with a constant stream of data quickly enough to not make them stop and start frequently because of buffer underruns.
I have three 15k drives in my "main" 150 and I would discourage to use a faster drive/tape combination than DDS3: Stop/start is happening rather frequently while saving QSYS.LIB, but less so when comparatively large files (NWSSTG) are to be read from the IFS.
Another 150 of mine has four 6606 drives (5400RPM). I observe likewise behavior with just a DDS2 drive/cartridge.

HTH.

:wq! PoC