On 6/24/10 6:03 PM, George Sinclair wrote:
> Frank Swasey wrote:
>> On 6/24/10 3:02 PM, George Sinclair wrote:
>>> Francis Swasey wrote:
>>>> On 6/24/10 12:41 PM, George Sinclair wrote:
>>>>> I know there's been a lot of discussion over having NW clean versus
>>>>> having the tape library do the cleaning. I realize that not all
>>>>> methods work best for everyone, but I have a fundamental technical
>>>>> question:
>>>>>
>>>>> If you do have the tape library do the cleaning, will most tape
>>>>> libraries wait until the drive is empty?
>>>>
>>>> I have a tape library that will only clean drives in physical mode,
>>>> and
>>>> since I run it in logical mode, I would have to shut NW down to let
>>>> the
>>>> library clean the tape drives -- it's a Qualstar XLS 8000 series, in
>>>> case you are wondering.
>>>
>>> What do you mean by physical mode versus logical mode?
>>
>> I'm sorry. The Tape Library allows being partitioned. In fact, back
>> in 2007 when we installed it, we had to partition it because on there
>> were unused tape drive slots and NW couldn't handle the idea of tape
>> drive slots that didn't have tape drives in them.
>>
>
> Ours can be partitioned, too. I think we have one partition, and all
> the slots are available for NW.
>
>> So, when I say physical mode, I mean all the logical partitions are
>> turned off and the tape library is operating on the real hardware
>> (instead of virtualizing it for the logical partitions).
>>
>>>
>>>>
>>>> Therefore, I have configured the library to send me an email when a
>>>> drive needs to be cleaned and I go check the box in NMC to tell
>>>> NetWorker to clean the drive...
>>>
>
> According to Dell, I can configure a cleaning slot on the physical
> tape library (no surprise), and the library will then use that slot to
> get a cleaner when a drive needs cleaning, *BUT* the cleaning will
> only happen when the drive is empty. I suspected as much because if a
> drive is idle, and it unloads a tape in the drive to clean the drive
> then NW would be out of the loop, and that would cause problems when
> NW later goes to unmount the tape since it would no longer be loaded,
> resulting in the 'invalid argument' error or some such thing.
>
> So, essentially, as long as the backup software has a reservation on
> the drive, the library won't clean it. Also, most of the drives always
> have tapes because even when NW is done writing, it doesn't just
> unmount a tape unless it needs another one, or there's a request to
> mount another or different pool tape. So, configuring a cleaning slot
> on the library doesn't seem to buy me much and 1. this will require
> having to re-partition the library so that the slot will not be
> available for normal operations or even to NW, 2. I'll then need to
> tell or reconfigure NW so it no longer has that slot available., and
> 3. How would I know that a drive had been cleaned and how would I know
> I was getting low on remaining cleanings, unless the library e-mails
> me? At least NW will decrement the uses, if I can get it to clean when
> it should.
I've never set up a library to clean its own drives -- So, I don't know
if NW keeps a reserve on the drive all the time or not. However, one
thing you could try is setting the idle timeout value in NW so the tapes
don't sit in the drive for extended periods of time without being used.
Then the drives would be empty and as long as NW doesn't hold a reserve
on the drive (and since I can use mt commands on linux to mess with the
drives, I don't think NW does hold a reserve) then the library should be
able to clean the drive. Hopefully, the library has some way of telling
you when the cleaning tape has been used up.
>
> I can configure the library to email me about events, however, and
> that would probably be worth doing so that if NW doesn't do it, at
> least I'll know there's a drive that needs cleaning without having to
> go look at the library GUI to find out. Still doesn't help me, though,
> if I'm gone.
>
>>> I might be able to do that on ours - it's a Dell ML6000, but mimics
>>> an ADIC Scalar i500 - but that won't help me if I'm out of town.
>>>
>>> I'd like to have NW do the cleaning. I do have a cleaning slot set
>>> aside in NW, and NW lists the cleaning tape in that slot and reports
>>> the number of uses left, but even though the 'Cleaning required'
>>> check box for a given drive does get turned on when a drive needs
>>> cleaning, it never loads the cleaning tape. I end up doing it
>>> manually from the library and then manually decrementing the 'Uses
>>> left' count. Also, I do have the cleaning even notifications in NW
>>> set to e-mail me, but I never receive any messages. I do get savegrp
>>> notifications, however, and the e-mail is the same.
>>>
>>> I do have 'Auto clean' turned on for the jukebox, but I also have
>>> the 'Cleaning interval' set to '6 months', and 'Date last cleaned'
>>> shows Jan 27, 2010, so obviously it won't clean until July 27 or so,
>>> but I thought it would still clean before then, assuming that it
>>> detected that the drive needed cleaning. We do have CDI set to
>>> 'SCSCI commands' under the Properties for the drives. Every time
>>> that the library indicates that a cleaning is required (amber light
>>> on GUI), NW checks the 'Cleaning required' box for that drive, so I
>>> know NW is picking this up.
>>>
>>> Do I need to make the 'Cleaning interval' blank in order to get NW
>>> to act on it?
>>
>> I do not think blank is a legal value for the cleaning interval.
>
> That's what I thought, too, but I just changed it to blank, and it
> took it with no complaints, so we'll see what happens the next time a
> drive needs cleaning. I originally set it to '6 months' because I
> thought that was far enough in the future that it would give me some
> time to play around until I found a solution, and I thought it had to
> be non-blank. Maybe that's what's kept NW from acting on it because
> the interval hadn't passed yet?
I think the interval is how often NW will clean the tape drive if it
never requests being cleaned. I believe if the drive sent a "CLEAN NOW"
tape alert (the one that indicates there have been read-back errors)
that NW would clean the drive regardless of the interval.
I have to admit that 7.5sp1 is something that I wouldn't touch with a
39.5 foot pole... It is missing too many fixes.
>
>>
>>>
>>> I'd really prefer not to have NW just clean at preset intervals, but
>>> I thought I had to have a value in the 'Cleaning interval' if 'Auto
>>> clean' was turned on?
>>
>> I agree. I want NW to clean the tape drive (I'm using LTO4 drives)
>> when the tape drive says, I've been sliding tape over my heads for
>> long enough that I should be cleaned... The bit I ran into is my
>> drives turn on the "Cleaning Required" light, when they send the
>> "Cleaning Request" TAPEALERT call, which NetWorker doesn't clean the
>> drives in response to (or didn't). I often found it in the same
>> situation you describe -- the check box was turned on, but the drive
>> didn't get cleaned. It would if I put it into service mode -- NW
>> would clean the drive immediately when I did that if the cleaning
>> check box had been checked by NW. If I check the box myself, NW will
>> clean the drive whether I put it in service mode or not.
>
> I've not tried the 'service mode' technique to force cleaning, but
> I'll try that next time, assuming NW doesn't act on it.
>
> I still find it odd, though, that NW doesn't send me an e-mail
> notification for cleaning? I have both of 'Device cleaned' and 'Device
> cleaning required' notification set up to email me, same as the
> savegrp notifications.
NW should send you a notification after it has cleaned the drive if it
cleans the drive itself (that includes when you manually check the
cleaning box and when you put the drive into service mode when NW has
checked the box but not cleaned the drive). NW does not send
notifications that the drive wants/needs to be cleaned. That's where I
depend on the library to notify me. In fact, truth be told, I trust the
library more than I trust NW.
>
> So, if you manually check that box, then NW cleans the drive, but was
> the box not already checked beforehand by NW?
NW will clean the drive when I check the box, only if NW has not already
checked the box. When NW has already checked the box, I have to put the
tape drive into service mode to force NW to clean the drive.
>
>>
>> I've forgotten, what version of NW are you working with?
>>
>
> Running 7.51
>
> George
>
>
--
Frank Swasey | http://www.uvm.edu/~fcs
Sr Systems Administrator | Always remember: You are UNIQUE,
University of Vermont | just like everyone else.
"I am not young enough to know everything." - Oscar Wilde (1854-1900)
To sign off this list, send email to listserv AT listserv.temple DOT edu and
type "signoff networker" in the body of the email. Please write to
networker-request AT listserv.temple DOT edu if you have any problems with this
list. You can access the archives at
http://listserv.temple.edu/archives/networker.html or
via RSS at http://listserv.temple.edu/cgi-bin/wa?RSS&L=NETWORKER
|
