Date: Sun, 1 Mar 2015 19:41:07 -0500 From: Dan Langille <dan@langille.org> To: "Kenneth D. Merry" <ken@FreeBSD.ORG> Cc: current@freebsd.org, scsi@freebsd.org Subject: Re: sa(4) driver changes available for test Message-ID: <D1C8E304-6DE7-4A03-A350-64E097EC4804@langille.org> In-Reply-To: <20150302003150.GB71528@mithlond.kdm.org> References: <20150214003232.GA63990@mithlond.kdm.org> <7CA52DF3-E073-4F50-BE4E-01C51CCDF2C7@langille.org> <20150217183645.GA30947@mithlond.kdm.org> <303C48AC-0DA8-447C-8DE7-0A1DD5DD7351@langille.org> <20150302003150.GB71528@mithlond.kdm.org>
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> On Mar 1, 2015, at 7:31 PM, Kenneth D. Merry <ken@FreeBSD.ORG> wrote:
>=20
> On Sun, Mar 01, 2015 at 19:15:05 -0500, Dan Langille wrote:
>>=20
>>> On Feb 17, 2015, at 1:36 PM, Kenneth D. Merry <ken@freebsd.org> =
wrote:
>>>=20
>>> On Sat, Feb 14, 2015 at 18:22:43 -0500, Dan Langille wrote:
>>>>=20
>>>>> On Feb 13, 2015, at 7:32 PM, Kenneth D. Merry <ken@freebsd.org> =
wrote:
>>>>>=20
>>>>>=20
>>>>> I have a fairly large set of changes to the sa(4) driver and mt(1) =
driver
>>>>> that I'm planning to commit in the near future.
>>>>>=20
>>>>> A description of the changes is here and below in this message.
>>>>>=20
>>>>> If you have tape hardware and the inclination, I'd appreciate =
testing and
>>>>> feedback.
>>>>=20
>>>> I have a DLT 8000 and an SDLT 220.
>>>>=20
>>>> I don't have anything running current, but I have a spare machine =
which I could use for testing.
>>>>=20
>>>> Do you see any value is tests with that hardware? I'd be testing it =
via Bacula.
>>>>=20
>>>> disclosure: I'm the sysutils/bacula-* maintainer and a Bacula =
committer.
>>>>=20
>>>=20
>>> Actually, yes. Bacula is a bit tricky to configure, so your trying =
it out
>>> would be helpful if you have the time.
>>>=20
>>> In looking at the manuals for both the SDLT 220 and the DLT 8000, =
they both
>>> claim to support long position information for the SCSI READ =
POSITION
>>> command.
>>>=20
>>> You can see what I'm talking about by doing:
>>>=20
>>> mt eod
>>> mt status
>>>=20
>>> On my DDS-4 tape drive, this shows:
>>>=20
>>> # mt -f /dev/nsa3 status
>>> Drive: sa3: <SEAGATE DAT 06240-XXX 8071> Serial Number: HJ00YWY
>>> ---------------------------------
>>> Mode Density Blocksize bpi Compression
>>> Current: 0x26:DDS-4 1024 bytes 97000 enabled =
(DCLZ)
>>> ---------------------------------
>>> Current Driver State: at rest.
>>> ---------------------------------
>>> Partition: 0 Calc File Number: -1 Calc Record Number: -1
>>> Residual: 0 Reported File Number: -1 Reported Record Number: -1
>>> Flags: None
>>>=20
>>> But on an LTO-5, which will give long position information, I get:
>>>=20
>>> [root@doc ~]# mt status
>>> Drive: sa0: <IBM ULTRIUM-HH5 E4J1>
>>> ---------------------------------
>>> Mode Density Blocksize bpi Compression
>>> Current: 0x58:LTO-5 variable 384607 enabled (0x1)
>>> ---------------------------------
>>> Current Driver State: at rest.
>>> ---------------------------------
>>> Partition: 0 Calc File Number: 2 Calc Record Number: -1
>>> Residual: 0 Reported File Number: 2 Reported Record Number: =
32373
>>> Flags: None
>>>=20
>>> That, in combination with the changes I made to the position =
information
>>> code in the driver, mean that even the old MTIOCGET ioctl should =
return an
>>> accurate file number at end of data. e.g., on the LTO-5:
>>>=20
>>> [root@doc ~]# mt ostatus
>>> Mode Density Blocksize bpi Compression
>>> Current: 0x58:LTO-5 variable 384607 0x1
>>> ---------available modes---------
>>> 0: 0x58:LTO-5 variable 384607 0x1
>>> 1: 0x58:LTO-5 variable 384607 0x1
>>> 2: 0x58:LTO-5 variable 384607 0x1
>>> 3: 0x58:LTO-5 variable 384607 0x1
>>> ---------------------------------
>>> Current Driver State: at rest.
>>> ---------------------------------
>>> File Number: 2 Record Number: -1 Residual Count -1
>>>=20
>>> So the thing to try, in addition to just making sure that Bacula =
continues
>>> to work properly, is to try setting this for the tape drive in
>>> bacula-sd.conf:
>>>=20
>>> Hardware End of Medium =3D yes
>>>=20
>>> It looks like the Bacula tape program (btape) has a test mode, and =
it would
>>> be good to run through the tests on one of the tape drives and see =
whether
>>> they work, and whether the results are different before and after =
the
>>> changes. I'm not sure how to enable the test mode.
>>=20
>> I have this in /usr/local/etc/bacula/bacula-sd.conf
>>=20
>> Device {
>> Name =3D DLT
>> Description =3D "QUANTUM DLT7000 1624"
>> Media Type =3D DLT
>> Archive Device =3D /dev/nsa1
>>=20
>> Autochanger =3D YES
>> Drive Index =3D 0
>>=20
>> Offline On Unmount =3D no
>> Hardware End of Medium =3D yes
>> BSF at EOM =3D yes
>> Backward Space Record =3D no
>> Fast Forward Space File =3D no
>> TWO EOF =3D yes
>> }
>>=20
>> FYI, http://www.freebsddiary.org/digital-tl891.php (from 2006) has a =
btape test on this same model.
>>=20
>> Here's the test I ran tonight:
>>=20
>> [root@cuppy:/usr/home/dan] # btape -c =
/usr/local/etc/bacula/bacula-sd.conf /dev/nsa1 =
=20
>> Tape block granularity is 1024 bytes.
>> btape: butil.c:287-0 Using device: "/dev/nsa1" for writing.
>> btape: btape.c:469-0 open device "DLT" (/dev/nsa1): OK
>> *test
>>=20
>> =3D=3D=3D Write, rewind, and re-read test =3D=3D=3D
>>=20
>> I'm going to write 10000 records and an EOF
>> then write 10000 records and an EOF, then rewind,
>> and re-read the data to verify that it is correct.
>>=20
>> This is an *essential* feature ...
>>=20
>> btape: btape.c:1152-0 Wrote 10000 blocks of 64412 bytes.
>> btape: btape.c:604-0 Wrote 1 EOF to "DLT" (/dev/nsa1)
>> btape: btape.c:1168-0 Wrote 10000 blocks of 64412 bytes.
>> btape: btape.c:604-0 Wrote 1 EOF to "DLT" (/dev/nsa1)
>> btape: btape.c:604-0 Wrote 1 EOF to "DLT" (/dev/nsa1)
>> btape: btape.c:1210-0 Rewind OK.
>> 10000 blocks re-read correctly.
>> Got EOF on tape.
>> 10000 blocks re-read correctly.
>> =3D=3D=3D Test Succeeded. End Write, rewind, and re-read test =3D=3D=3D=
>>=20
>> btape: btape.c:1277-0 Block position test
>> btape: btape.c:1289-0 Rewind OK.
>> Reposition to file:block 0:4
>> Block 5 re-read correctly.
>> Reposition to file:block 0:200
>> Block 201 re-read correctly.
>> Reposition to file:block 0:9999
>> Block 10000 re-read correctly.
>> Reposition to file:block 1:0
>> Block 10001 re-read correctly.
>> Reposition to file:block 1:600
>> Block 10601 re-read correctly.
>> Reposition to file:block 1:9999
>> Block 20000 re-read correctly.
>> =3D=3D=3D Test Succeeded. End Write, rewind, and re-read test =3D=3D=3D=
>>=20
>>=20
>>=20
>> =3D=3D=3D Append files test =3D=3D=3D
>>=20
>> This test is essential to Bacula.
>>=20
>> I'm going to write one record in file 0,
>> two records in file 1,
>> and three records in file 2
>>=20
>> btape: btape.c:574-0 Rewound "DLT" (/dev/nsa1)
>> btape: btape.c:1907-0 Wrote one record of 64412 bytes.
>> btape: btape.c:1909-0 Wrote block to device.
>> btape: btape.c:604-0 Wrote 1 EOF to "DLT" (/dev/nsa1)
>> btape: btape.c:1907-0 Wrote one record of 64412 bytes.
>> btape: btape.c:1909-0 Wrote block to device.
>> btape: btape.c:1907-0 Wrote one record of 64412 bytes.
>> btape: btape.c:1909-0 Wrote block to device.
>> btape: btape.c:604-0 Wrote 1 EOF to "DLT" (/dev/nsa1)
>> btape: btape.c:1907-0 Wrote one record of 64412 bytes.
>> btape: btape.c:1909-0 Wrote block to device.
>> btape: btape.c:1907-0 Wrote one record of 64412 bytes.
>> btape: btape.c:1909-0 Wrote block to device.
>> btape: btape.c:1907-0 Wrote one record of 64412 bytes.
>> btape: btape.c:1909-0 Wrote block to device.
>> btape: btape.c:604-0 Wrote 1 EOF to "DLT" (/dev/nsa1)
>> btape: btape.c:604-0 Wrote 1 EOF to "DLT" (/dev/nsa1)
>> btape: btape.c:469-0 open device "DLT" (/dev/nsa1): OK
>> btape: btape.c:574-0 Rewound "DLT" (/dev/nsa1)
>> btape: btape.c:1420-0 Now moving to end of medium.
>=20
> This is the critical piece. The test moves the tape to the end of the
> medium. With hardware position information, you can tell what =
filemark
> you're on. Without it, you can't.
>=20
>> btape: btape.c:622-0 tape_dev.c:345 ioctl MTIOCGET error on "DLT" =
(/dev/nsa1). ERR=3DNo error: 0.
>> We should be in file 3. I am at file 0. This is NOT correct!!!!
>>=20
>> Append test failed. Attempting again.
>> Setting "Hardware End of Medium =3D no
>> and "Fast Forward Space File =3D no
>> and retrying append test.
>=20
> This is not surprsing, given that the drive doesn't support long read
> position data. (It's a SCSI-2 device.) So that means that Bacula =
will
> need to do it manually.
Yes, I have nothing newer than SCSI-2. Even my SDLT is SCSI-2 but that
tape library is hooked up to a different computer and was doing backups =
today.
> =3D=3D=3D Append files test =3D=3D=3D
>>=20
>> This test is essential to Bacula.
>>=20
>> I'm going to write one record in file 0,
>> two records in file 1,
>> and three records in file 2
>>=20
>> btape: btape.c:574-0 Rewound "DLT" (/dev/nsa1)
>> btape: btape.c:1907-0 Wrote one record of 64412 bytes.
>> btape: btape.c:1909-0 Wrote block to device.
>> btape: btape.c:604-0 Wrote 1 EOF to "DLT" (/dev/nsa1)
>> btape: btape.c:1907-0 Wrote one record of 64412 bytes.
>> btape: btape.c:1909-0 Wrote block to device.
>> btape: btape.c:1907-0 Wrote one record of 64412 bytes.
>> btape: btape.c:604-0 Wrote 1 EOF to "DLT" (/dev/nsa1)
>> btape: btape.c:1907-0 Wrote one record of 64412 bytes.
>> btape: btape.c:1909-0 Wrote block to device.
>> btape: btape.c:1907-0 Wrote one record of 64412 bytes.
>> btape: btape.c:1909-0 Wrote block to device.
>> btape: btape.c:1907-0 Wrote one record of 64412 bytes.
>> btape: btape.c:1909-0 Wrote block to device.
>> btape: btape.c:604-0 Wrote 1 EOF to "DLT" (/dev/nsa1)
>> btape: btape.c:604-0 Wrote 1 EOF to "DLT" (/dev/nsa1)
>> btape: btape.c:469-0 open device "DLT" (/dev/nsa1): OK
>> btape: btape.c:574-0 Rewound "DLT" (/dev/nsa1)
>> btape: btape.c:1420-0 Now moving to end of medium.
>> btape: btape.c:625-0 Moved to end of medium.
>> We should be in file 3. I am at file 3. This is correct!
>>=20
>> Now the important part, I am going to attempt to append to the tape.
>>=20
>> btape: btape.c:1907-0 Wrote one record of 64412 bytes.
>> btape: btape.c:1909-0 Wrote block to device.
>> btape: btape.c:604-0 Wrote 1 EOF to "DLT" (/dev/nsa1)
>> btape: btape.c:604-0 Wrote 1 EOF to "DLT" (/dev/nsa1)
>> btape: btape.c:574-0 Rewound "DLT" (/dev/nsa1)
>> Done appending, there should be no I/O errors
>>=20
>> Doing Bacula scan of blocks:
>> 1 block of 64448 bytes in file 1
>> End of File mark.
>> 2 blocks of 64448 bytes in file 2
>> End of File mark.
>> 3 blocks of 64448 bytes in file 3
>> End of File mark.
>> 1 block of 64448 bytes in file 4
>> End of File mark.
>> Total files=3D4, blocks=3D7, bytes =3D 451,136
>> End scanning the tape.
>> We should be in file 4. I am at file 4. This is correct!
>>=20
>>=20
>> It looks like the test worked this time, please add:
>>=20
>> Hardware End of Medium =3D No
>>=20
>> Fast Forward Space File =3D No
>> to your Device resource in the Storage conf file.
>>=20
>> The above Bacula scan should have output identical to what follows.
>> Please double check it ...
>> =3D=3D=3D Sample correct output =3D=3D=3D
>> 1 block of 64448 bytes in file 1
>> End of File mark.
>> 2 blocks of 64448 bytes in file 2
>> End of File mark.
>> 3 blocks of 64448 bytes in file 3
>> End of File mark.
>> 1 block of 64448 bytes in file 4
>> End of File mark.
>> Total files=3D4, blocks=3D7, bytes =3D 451,136
>> =3D=3D=3D End sample correct output =3D=3D=3D
>>=20
>> If the above scan output is not identical to the
>> sample output, you MUST correct the problem
>> or Bacula will not be able to write multiple Jobs to=20
>> the tape.
>>=20
>> Skipping read backwards test because BSR turned off.
>>=20
>>=20
>> =3D=3D=3D Forward space files test =3D=3D=3D
>>=20
>> This test is essential to Bacula.
>>=20
>> I'm going to write five files then test forward spacing
>>=20
>> btape: btape.c:574-0 Rewound "DLT" (/dev/nsa1)
>> btape: btape.c:1907-0 Wrote one record of 64412 bytes.
>> btape: btape.c:1909-0 Wrote block to device.
>> btape: btape.c:604-0 Wrote 1 EOF to "DLT" (/dev/nsa1)
>> btape: btape.c:1907-0 Wrote one record of 64412 bytes.
>> btape: btape.c:1909-0 Wrote block to device.
>> btape: btape.c:1907-0 Wrote one record of 64412 bytes.
>> btape: btape.c:1909-0 Wrote block to device.
>> btape: btape.c:604-0 Wrote 1 EOF to "DLT" (/dev/nsa1)
>> btape: btape.c:1907-0 Wrote one record of 64412 bytes.
>> btape: btape.c:1909-0 Wrote block to device.
>> btape: btape.c:1907-0 Wrote one record of 64412 bytes.
>> btape: btape.c:1909-0 Wrote block to device.
>> btape: btape.c:1907-0 Wrote one record of 64412 bytes.
>> btape: btape.c:1909-0 Wrote block to device.
>> btape: btape.c:604-0 Wrote 1 EOF to "DLT" (/dev/nsa1)
>> btape: btape.c:1907-0 Wrote one record of 64412 bytes.
>> btape: btape.c:1909-0 Wrote block to device.
>> btape: btape.c:1907-0 Wrote one record of 64412 bytes.
>> btape: btape.c:1909-0 Wrote block to device.
>> btape: btape.c:604-0 Wrote 1 EOF to "DLT" (/dev/nsa1)
>> btape: btape.c:1907-0 Wrote one record of 64412 bytes.
>> btape: btape.c:1909-0 Wrote block to device.
>> btape: btape.c:604-0 Wrote 1 EOF to "DLT" (/dev/nsa1)
>> btape: btape.c:604-0 Wrote 1 EOF to "DLT" (/dev/nsa1)
>> btape: btape.c:574-0 Rewound "DLT" (/dev/nsa1)
>> btape: btape.c:1634-0 Now forward spacing 1 file.
>> We should be in file 1. I am at file 1. This is correct!
>> btape: btape.c:1646-0 Now forward spacing 2 files.
>> We should be in file 3. I am at file 3. This is correct!
>> btape: btape.c:574-0 Rewound "DLT" (/dev/nsa1)
>> btape: btape.c:1659-0 Now forward spacing 4 files.
>> We should be in file 4. I am at file 4. This is correct!
>>=20
>> btape: btape.c:1677-0 Now forward spacing 1 more file.
>> We should be in file 5. I am at file 5. This is correct!
>>=20
>> =3D=3D=3D End Forward space files test =3D=3D=3D
>>=20
>>=20
>> Ah, I see you have an autochanger configured.
>> To test the autochanger you must have a blank tape
>> that I can write on in Slot 1.
>>=20
>> Do you wish to continue with the Autochanger test? (y/n): y
>>=20
>>=20
>> =3D=3D=3D Autochanger test =3D=3D=3D
>>=20
>> 3301 Issuing autochanger "loaded" command.
>> Nothing loaded in the drive. OK.
>> 3303 Issuing autochanger "load 1 0" command.
>> 3303 Autochanger "load 1 0" status is OK.
>> btape: btape.c:469-0 open device "DLT" (/dev/nsa1): OK
>> btape: btape.c:1564-0 Rewound "DLT" (/dev/nsa1)
>> btape: btape.c:1571-0 Wrote EOF to "DLT" (/dev/nsa1)
>>=20
>> The test autochanger worked!!
>=20
> Great, thanks for running the test! Looks like things are working as =
well
> as they were before.
>=20
>>>=20
>>>> I'll let the other Bacula devs know about this. They deal with the =
hardware. I work on PostgreSQL.
>>>>=20
>>>=20
>>> Thanks! If there are additional features they would like out of the =
tape
>>> driver, I'm happy to talk about it. (Or help if they'd like to use =
the new
>>> status reporting ioctl, MTIOCEXTGET or any of the other new ioctls.)
>>=20
>> Errors are interesting to me. Especially corrected errors. They are =
a good indicator of tape quality.
>>=20
>=20
> Yes. At least on modern drives, there is a good bit available in the =
log
> pages. You can try seeing what logs your drive supports by installing =
the
> sg3_utils package and running 'sg_logs sa1 --all'.
>=20
> Given the large amount of data available on some drives, and the =
difficulty
> distilling it down to a clear good/bad, I probably won't stick that in =
the
> 'mt status' output.
>=20
> But you can certainly take a look at it and have an idea of whether =
your
> particular tape/drive are experiencing issues.
That's a lot of output: =
https://gist.github.com/dlangille/0e15a7fbf7acab56fd32
I will run some Bacula jobs soon. I'm still setting up config files.
=E2=80=94=20
Dan Langille
http://langille.org/
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