Date: Mon, 14 Oct 1996 16:02:45 -0500 (CDT) From: Joe Greco <jgreco@brasil.moneng.mei.com> To: hdalog@zipnet.net Cc: rgrimes@GndRsh.aac.dev.com, freebsd-scsi@FreeBSD.org, joerg_wunsch@uriah.heep.sax.de Subject: Re: Buslogic controller, Sync mode & a SCSI disk error Message-ID: <199610142102.QAA24924@brasil.moneng.mei.com> In-Reply-To: <199610142105.RAA19326@hda.com> from "Peter Dufault" at Oct 14, 96 05:05:03 pm
next in thread | previous in thread | raw e-mail | index | archive | help
> > > 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.
Hello Peter,
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[2]:
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.
... JG
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199610142102.QAA24924>