I should also add, that even though I have
18 drives avail to each server, the number of drives used at one time is still
based on policy and which storage unit it uses ( as you set how many tape
drives are in a storage unit.)
So serverA zoned to all 18 drives.
Storage unit is 2 drives at a time.
Then serverA still only uses 2 drives at a
time out of the 18 that might be available.
From:
veritas-bu-bounces AT mailman.eng.auburn DOT edu
[mailto:veritas-bu-bounces AT mailman.eng.auburn DOT edu] On Behalf Of judy_hinchcliffe AT administaff DOT com
Sent: Tuesday, June 30, 2009 4:23
PM
To: Mark.Donaldson AT Staples DOT com;
Dturner AT manh DOT com; veritas-bu AT mailman.eng.auburn DOT edu
Cc: WTucker AT manh DOT com
Subject: Re: [Veritas-bu] SSO
Option for LTO3 drives
I agree if you are only zoning each drive
to one media server the SSO is not needed.
However! If those two drives fail
– bad tape – bad whatever and are down then that media server has
NO tape drives avail.
I have 18 tape drives and have zoned all
18 to all of them to all 4 of my media servers.
So they use tape drives based on
NB’s algorithm of which drive to use next kind of evening out the usage
some what, and if two drives go down the there are still 16 drives available
for the media server to try and find one not busy.
From:
veritas-bu-bounces AT mailman.eng.auburn DOT edu
[mailto:veritas-bu-bounces AT mailman.eng.auburn DOT edu] On Behalf Of Donaldson, Mark
Sent: Tuesday, June 30, 2009 4:05
PM
To: David Turner;
veritas-bu AT mailman.eng.auburn DOT edu
Cc: Will Tucker
Subject: Re: [Veritas-bu] SSO
Option for LTO3 drives
If a drive is visible to one and only
one server because of zoning , then SSO isn't necessary. SSO is used to
share a single drive among multiple media servers. Each server uses it in
turn but then releases it after use to be used by a different server.
While you may be licensed for SSO, what you're describing won't need it.
You could still limit the use of drives
by each media server through multiple techniques - storage units "max
drive" setting comes to mind - so that only X number of drives are used
simultaneously per media server. You could still have it choose that X
drives from a shared pool of all your drives. I suspect your servers are
more than capable of keeping two drives busy (subject to throttling introduced
by your back-end SAN & HBA speeds).
Your storage guys are, IMO, being too
conservative.
From:
veritas-bu-bounces AT mailman.eng.auburn DOT edu [mailto:veritas-bu-bounces AT mailman.eng.auburn DOT edu]
On Behalf Of David Turner
Sent: Tuesday, June 30, 2009 2:55
PM
To:
veritas-bu AT mailman.eng.auburn DOT edu
Cc: Will Tucker
Subject: [Veritas-bu] SSO Option
for LTO3 drives
I
have 1 windows master running Netbackup 6.5 with 3 media servers. I have
Storagetek/Sun SL8500 with 8 LTO3 tape drives (2 drives are dedicated via
NDMP to a Netapp 3050). All drives are connected via FC to brocade etc. we have
the Shared storage option but I don’t think it’s working properly.
How can I verify that its working?
I
believe the engineers that configured the zoning on the switch dedicated 2
drives per server and dedicate 2 to the Netapp. Did it makes sense to purchase
SSO?
I
was told you should only have 2 LTO3 drives per servers because of “shoe
shining” and the servers ability to handle more than 2 drives (Dell
2950’s quad cores with 8gig of ram). I am wondering if the switch should
be rezoned to make use of SSO or can the zoning have an impact on how SSO
should be configured? How can these 2 play together?
As
you can see I am all confused and would love for someone to explain this in
simple terms.
thanks
