Hello Alexander
Netbackup's cleaning algorithm is strictly time based i.e.: it keeps track of
how many hours a given drive is in use and once it reaches a certain value, the
cleaning tape is run through it. Many robots have the ability to sense when a
drive requests cleaning and therefore minimize your cleaning cycles to the
absolute minimum number of cycles needed, these have little wires plugged into
the jumpers on the back of the tape drive.
It's really a matter of preference as to which way you want to go.
I use the Netbackup cleaning cycle because it's convenient for me to issue a
clean command when I feel that a given drives heads have drifted in alignment
(cleaning usually also aligns the heads), I know when it's getting cleaned and I
don't mind cleaning a bit more often than absolutely required. I also never
have more than one cleaning tape in a tape library at any given time since I
want all the drives to align their heads to the same reference.
The way I have it set up is that I've established a barcode rule such that any
tape with a given prefix would be recognized by Netbackup as a cleaning tape
when injected into the tape library with the vmupdate command with the
-use_barcode_rules flag. That's easier than manually adding a tape as a
cleaning tape either from the GUI or the command line but the prefix isn't
absolutely necessary, just convenient. After that I use the tpclean command to
adjust the cleaning frequency, report on status and issue manual clean requests;
of course you can do that from the device manager GUI as well.
Note having Netbackup recognize a given prefix (CLT in my case) as a cleaning
tape is not the default configuration, you have to add a barcode rule to do it.
Indeed, there's no default setting for the number of hours before a cleaning is
needed so you need to set that as well.
Also note, different media have different numbers of cleanings available on a
cleaning tape, AIT2 cleaning tapes are good for 70 cycles. I've forgotten what
the DLT was but I think it was something like 30 cycles, Exabytes ranged from
the original 12 cycles to 24 cycles with the 8505 drives and I don't know about
the Mammoth's. That might be something to stuff into the FAQ, the number of
cleaning cycles for each media type since it takes a fair bit of grovelling
through the net to get them, nah I'd probably still wind up surfing the net for
them each time. My big problem is I never know how many times a given tape has
already been used manually by previous administrators so I'm always coming onto
a site, setting up cleaning using half the number of cycles to be safe and
crying to management for new cleaning tapes.
The desired cleaning frequency is often hard to figure out, AIT2 tape drives
have internal cleaning mechanisms so they can go without cleaning for long
periods of time but I still use a cleaning frequency of 600 to try and hit them
every month to two months. The old 9 and 18 track guidelines was to clean the
tape once for every five tapes passed through the drive (anyone else remembers
cleaning with lint free swatches, swabs and a can of solution?), with Exabytes,
I used to clean them once every three tapes which would correspond with about 12
hours. You might want to try some trial and error where you pick an arbitrary
cleaning frequency perhaps based on the amount of time it takes to read one tape
multiply by 3 and then double it until you start getting errors and then half
the difference until it runs clean again.
Check your media log reports frequently to see if you are having tape problems.
Correlate them by tape and by drive to try and guess if it's a bad tape or a
drive needing attention.
Regards,
John I Wang
Sr. Systems Engineer
Steverson Information Professionals
---
Enron Networks
Enron Building room 3427e
ph (713) 345-4888
cell (832) 493-1263
fax (713) 646-8462
pg pagejwang AT skytel DOT com or 1-877-390-4155
|--------+----------------------->
| | Alex.Alonzo@t|
| | rw.com |
| | |
| | 09/05/01 |
| | 04:25 PM |
| | |
|--------+----------------------->
>---------------------------------------------------------------------------|
| |
| To: veritas-bu AT mailman.eng.auburn DOT edu
|
| cc: (bcc: John Wang/Contractor/Enron Communications) |
| Subject: [Veritas-bu] Tape Alert Setup |
>---------------------------------------------------------------------------|
NB Users:
Can anyone explain the steps I need to do to enable Tape Alert on our NB 3.4
setup, we currently have the STK 9710
robot doing the cleaning and we change the tape after 20 cleanings. All I know I
must shutoff the robot cleaning, add a
cleaning tape with a CLN bar code to robot & inventory it.
What else and is there and is there a correct sequence ?
Alexander Alonzo
E-Enterprise
TRW Space & Electronics Group
*? alex.alonzo AT trw DOT com
* 310.814.6097
_______________________________________________
Veritas-bu maillist - Veritas-bu AT mailman.eng.auburn DOT edu
http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu
**********************************************************************
This e-mail is the property of Enron Corp. and/or its relevant affiliate and
may contain confidential and privileged material for the sole use of the
intended recipient (s). Any review, use, distribution or disclosure by others
is strictly prohibited. If you are not the intended recipient (or authorized to
receive for the recipient), please contact the sender or reply to Enron Corp.
at enron.messaging.administration AT enron DOT com and delete all copies of the
message. This e-mail (and any attachments hereto) are not intended to be an
offer (or an acceptance) and do not create or evidence a binding and
enforceable contract between Enron Corp. (or any of its affiliates) and the
intended recipient or any other party, and may not be relied on by anyone as
the basis of a contract by estoppel or otherwise. Thank you.
**********************************************************************
|
