Re: async pass(4) patches available

"Kenneth D. Merry" <ken_at_FreeBSD.ORG> wrote:

> I have put patches to add an asynchronous interface to the pass(4) driver
> and add a new camdd(8) utility here:
> 
> FreeBSD/head as of SVN revision 280857:
> 
> http://people.freebsd.org/~ken/async_pass.head.20150330.1.txt
[...]
> Comments and testing are welcome!  As I said, camdd(8) in particular is a
> work in progress.  It could use some cleanup and there are some more
> useful features that could be added there.

I've been using the patch for a couple of days on an amd64 system
based on 11.0-CURRENT r280952 and didn't notice any obvious
regressions using the system as usual.

Scrubbing a pool once revealed checksum errors which I haven't
seen before:

[fk_at_kendra ~]$ zpool status -v dpool
  pool: dpool
 state: ONLINE
status: One or more devices has experienced an unrecoverable error.  An
        attempt was made to correct the error.  Applications are unaffected.
action: Determine if the device needs to be replaced, and clear the errors
        using 'zpool clear' or replace the device with 'zpool replace'.
   see: http://illumos.org/msg/ZFS-8000-9P
  scan: scrub repaired 0 in 1h52m with 0 errors on Thu Apr  2 13:01:44 2015
config:

        NAME                  STATE     READ WRITE CKSUM
        dpool                 ONLINE       0     0     0
          gpt/dpool-ada0.eli  ONLINE       0     0     6

errors: No known data errors

Apr  2 12:31:34 kendra kernel: (ada0:ahcich0:0:0:0): READ_FPDMA_QUEUED. ACB: 60 30 17 61 55 40 31 00 00 00 00 00
Apr  2 12:31:34 kendra kernel: (ada0:ahcich0:0:0:0): CAM status: ATA Status Error
Apr  2 12:31:34 kendra kernel: (ada0:ahcich0:0:0:0): ATA status: 51 (DRDY SERV ERR), error: 40 (UNC )
Apr  2 12:31:34 kendra kernel: (ada0:ahcich0:0:0:0): RES: 51 40 3e 61 55 40 31 00 00 00 00
Apr  2 12:31:34 kendra kernel: (ada0:ahcich0:0:0:0): Error 5, Retries exhausted
Apr  2 12:31:34 kendra kernel: GEOM_ELI: g_eli_read_done() failed gpt/dpool-ada0.eli[READ(offset=414970949120, length=24576)]

However the issue doesn't seem to be (easily) reproducible
and could be unrelated.

I also tried to test camdd, but didn't get it to work.
Some failed attempts:

[fk_at_kendra ~]$ sudo camdd -i pass=da0,bs=65536 -o file=blafsel.img
(pass2:umass-sim0:0:0:0): READ(6). CDB: 08 00 00 00 80 00 
(pass2:umass-sim0:0:0:0): CAM status: CCB request completed with an error
13 bytes read from pass2
13 bytes written to blafsel.img
20.3203 seconds elapsed
0.00 MB/sec
[fk_at_kendra ~]$ sudo hd blafsel.img 
00000000  55 53 42 53 d9 02 00 00  00 00 01 00 01           |USBS.........|
0000000d
[fk_at_kendra ~]$ sudo dd if=/dev/da0 bs=1k count=1  | hd | head -n 1
1+0 records in
1+0 records out
1024 bytes transferred in 0.000603 secs (1697756 bytes/sec)
00000000  fc 31 c0 8e c0 8e d8 8e  d0 bc 00 0e be 1a 7c bf  |.1............|.|

Trying the block size suggested in the manual result in:

[fk_at_kendra ~]$ sudo camdd -i pass=da0,bs=1M -o file=blafsel.img
camdd: camdd_pass_run: error sending CAMIOQUEUE ioctl to pass2: Invalid argument
camdd: camdd_pass_run: CCB address is 0x80250e420: Invalid argument
0 bytes read from pass2
0 bytes written to blafsel.img
0.0007 seconds elapsed
0.00 MB/sec

Apr  5 19:08:20 kendra kernel: (pass2:umass-sim0:0:0:0): passmemsetup: data length 1048576 > max allowed 65536 bytes

Fabian