Ben,
I have heard it's not about the amount of data but the type of adapters you are
using.
I think recent Emulex FC adapters can mix tape/disk data but for instance
Qlogic FC adapters don't do so well mixing tape and disk.
I guess if you want multi path failover to you tape drives (some devices
support this) you need 4 HBA's if you want to split the disk/tape data.
That's a hefty amount of money and if I were you I would read into it.
Stefan
-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU]On Behalf Of
Ben Bullock
Sent: woensdag 8 maart 2006 0:42
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: [ADSM-L] LAN FREE Backup
Thanks for the input. It sounds like the "separate adapters" is a good
idea. It would probably depend on how large or how busy your TSM server
is before you start to see these stream VS block issues.
Thanks,
Ben
-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
Nast, Jeff P.
Sent: Tuesday, March 07, 2006 3:48 PM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: LAN FREE Backup
Hi Ben,
I was remotely involved with this sort of problem about a year ago.
Another hospital in the area had a host machine that was using a
FASTt700 and FC tape over the same HBAs. They had lots of problems both
from the disk and tape point of view and the CE was replacing parts left
and right to no avail. As soon as I heard of their problem I told the CE
to have them move the disk and tape to separate HBAs. But their VAR said
no way is that the problem. So the hospital suffered for another 5
months until they finally tried it and things worked fine after that.
With the most HBA drivers comes a read.me file that states:
1.2 Limitations
---------------
Inter-operability with tape devices is supported on separate FC HBA
and
FC switch zones...
Someone may correct me here, but if memory serves... the tape devices
were put on streaming (selector) channels and disk on block channels.
Some tape operations can use very long sustained continous data streams,
thus not allowing access to the channel by other devices on the same
channel. A problem for timing sensitive disk. Block devices on the hand
have smaller "blocks" of data on the channel and allow other devices
more chances to access the channel.
I have heard of tape and disk coexisting on one HBA and working, but it
is not recommended nor supported by IBM. Your mileage may vary...
-Jeff
SMDC
http://www.smdc.org
-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU]On Behalf Of
Ben Bullock
Sent: Tuesday, March 07, 2006 15:15
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: LAN FREE Backup
That brings up a question. I know if the past, we were told not
to mix DISK and TAPE resources on the same FC HBA, but is that
suggestion still valid?
Will it not work at all? Or will it work but extremely poorly
because of the different types of data flows?
Just curious if something has changed in the last few years of
FC architecture that makes this rule-of-thumb no longer apply...
Ben
-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
Rubie Lim
Sent: Tuesday, March 07, 2006 2:09 PM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: LAN FREE Backup
Thanks. I have 3 clients to put on LAN FREE backup, but 2 of them cannot
have more than 2 HBA's, what route should I go? And these 2 HBA's is
needed for disk for redundancy.
Rubie
-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
Nast, Jeff P.
Sent: Tuesday, March 07, 2006 10:24 AM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: [ADSM-L] LAN FREE Backup
Yes, you need to zone tape drives to the machine running Storage
Manager.
Multiple tape drives can use the same HBA.
Tape and Disk cannot coincide on the same HBA. You need a separate
adapters for disk and tape. This stems from the days of S360 (and
earlier?) where there were seperate channels for streaming channels
(tape) and block channels (disk). Guess this dates me...
-Jeff "old timer" Nast
-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU]On Behalf Of
Rubie Lim
Sent: Tuesday, March 07, 2006 10:01
To: ADSM-L AT VM.MARIST DOT EDU
Subject: LAN FREE Backup
I am trying to implement a LAN FREE backup, and my question on the
Storage Agent/Client, do I need to create a zone from one of my HBA to
the Fiber Channel Tape drives? And if I can share the HBA with disk and
tape?
Any help is greatly appreciated.
Thanks,
Rubie
This e-mail communication and any attachments may contain confidential
and privileged information for the use of the designated recipients
named above. If you are not the intended recipient, you are hereby
notified that you have received this communication in error and that any
review, disclosure, dissemination, distribution or copying of it or its
contents is prohibited. As required by federal and state laws, you need
to hold this information as privileged and confidential. If you have
received this communication in error, please notify the sender and
destroy all copies of this communication and any attachments.
|
