low-level format a spinning hard drive
On this vintage Unix workstation machine I still got one of those spinning SCSI drives. The one in the SPARCstation 2 –spinning with 7200rpm, from 1999!– had some bad blocks at the end. First I partitioned it so that the OS would not touch them, but as I wanted to re-install a new, slightly different T2 build I wanted to try to get rid of this bad blocks. From the spec it sounds like those old drives may only re-map reserve spare blocks on low-level format, as opposed to any write like modern disk drives do. “Flawed sector reallocation at format time”, however, the document also mention “Programmable auto write and read reallocation”, “Reallocation of defects on command (Post format)” and even “Full automatic read and write reallocation” hm, … confusing.
Anyways, I did not really wanted to do a longer term install with this bad blocks so I tried the sgutils’s sg_format for the first time ever. Little bit of a scary thing, and you should certainly not do this light hearted. After issues the SCSI FORMAT command, the drive is busy and won’t respond to regular SCSI commands. I run for an hour, so I guess it was stuck ad some bad area. I turned if off, guessing this may render it bricked, and it came back online without responding to SCSI READ and WRITES, … I issues another FORMAT; in the hope it may complete, and after only some minutes it did, ..! Yay, good luck.
So do not try this too easy and too often. I still have to re-read the drive to see if it still gives read errors, or if the reallocation re-mapping of reserve sectors was successful.
