|Peter Dufault||Oct 8, 1996 12:28 pm|
|Gordon Henderson||Oct 10, 1996 10:08 am|
|Rodney W. Grimes||Oct 10, 1996 2:50 pm|
|Joe Greco||Oct 11, 1996 6:57 am|
|J Wunsch||Oct 12, 1996 1:54 pm|
|Gordon Henderson||Oct 14, 1996 5:33 am|
|Joe Greco||Oct 14, 1996 6:21 am|
|Rodney W. Grimes||Oct 14, 1996 8:17 am|
|Joe Greco||Oct 14, 1996 8:37 am|
|J Wunsch||Oct 14, 1996 9:53 am|
|Joe Greco||Oct 14, 1996 11:00 am|
|Joe Greco||Oct 14, 1996 2:02 pm|
|Peter Dufault||Oct 14, 1996 2:04 pm|
|Subject:||Re: Buslogic controller, Sync mode & a SCSI disk error|
|From:||Joe Greco (jgr...@brasil.moneng.mei.com)|
|Date:||Oct 14, 1996 2:02:25 pm|
scsiformat(8) is destructive only, I can't fix a drive full of data with it. :-(. How hard would it be to extend it so that it does what the aha2940 ``verify'' mode does?
Perhaps even with a nicer interface :-) Personally I am quite fond of the "analyze" feature available in Sun format, but that is also a fair amount of additional work.
What do these utilities do? How do they look? How different is the behavior from doing a read/write loop over an unmounted raw disk after ensuring AWRE/ARRE are on, possibly with a read retry count and a "force write to sector N if you exceed read retry errors at sector N" option?
Since these read failures typically indicate the drive tried its best already (and our system has issued additional retries also), I'm not sure of what these utilities do other than possibly turning off error checking and reading as much as it can.
The Adaptec utility appears to simply read all the sectors on the disk, looking for bad sectors. I am not sure what it does to deal with the bad sectors it finds - it simply gives an option to "correct" the errors found. How it is done, I don't know.
The Sun format / analyze tool is a bit nicer. It provides a unified formatting/partitioning/error correction interface that is really not too hard to work with:
# format Searching for disks...done
AVAILABLE DISK SELECTIONS: 0. c0t3d0 <MEI QL 540 cyl 2799 alt 2 hd 3 sec 128>
/iommu@0,10000000/sbus@0,10001000/espdma@4,8400000/esp@4,8800000/sd@3,0 Specify disk (enter its number): 0 selecting c0t3d0 [disk formatted]
FORMAT MENU: disk - select a disk type - select (define) a disk type partition - select (define) a partition table current - describe the current disk format - format and analyze the disk repair - repair a defective sector label - write label to the disk analyze - surface analysis defect - defect list management backup - search for backup labels verify - read and display labels save - save new disk/partition definitions inquiry - show vendor, product and revision volname - set 8-character volume name quit format> ana
ANALYZE MENU: read - read only test (doesn't harm SunOS) refresh - read then write (doesn't harm data) test - pattern testing (doesn't harm data) write - write then read (corrupts data) compare - write, read, compare (corrupts data) purge - write, read, write (corrupts data) print - display data buffer setup - set analysis parameters config - show analysis parameters quit analyze> setup Analyze entire disk[yes]? Loop continuously[no]? Enter number of passes: Repair defective blocks[yes]? Stop after first error[no]? Use random bit patterns[no]? Enter number of blocks per transfer[126, 0/0/126]: Verify media after formatting[yes]? Enable extended messages[no]? Restore defect list[yes]? Restore disk label[yes]?
analyze> read Ready to analyze (won't harm SunOS). This takes a long time, but is interruptable with CTRL-C. Continue? y
pass 0 ^C 38/1/22 Total of 0 defective blocks repaired. analyze>
Anyways the various tests allow you to perform a variety of read/write operations to check the disk. The "read" test may be run on mounted partitions, the "refresh" and "test" tests will not corrupt data because they read and restore the information that was on the disk, and the others are more brutal.
The "read" test appears to be substantially similar to the Adaptec utility.
This is a really nice tool. It is not a beginners tool, but it does a lot to avoid the annoyance and mistakes that are so easy to make when dealing with SCSI disks.