Multiple Databases per volume ??

hi all,
i do not understand this point : "Multiple Databases per volume let you have both active and passive databases on the same volume " ok right
it was also possible in Exchange 2010 in jbod configuration...
in place in our orga 2010.
2 dag member : 2 disk par server
disk 1 :
DB1 + logs active
DB2 + log passive
Disk 2
DB2 + logs active
DB1 + log passive
it s the reason why i dont get the enhancement for this point..
can somebody kindly explain me why Multiple Databases per volume in ex 2013 is a new feature?
regards,

i think i get it.
in 2010 it was possible but not supported.
Now because of decrease of IOPS in 2013 it is officially supported. right ?
i got confused because of that :
"Multiple databases per volumeis a new JBOD scenario available
in Exchange 2013 that allows for active and passive copies (including lagged copies) to be mixed on a single disk"
https://technet.microsoft.com/en-us/library/ee832792%28v=exchg.150%29.aspx#Best
Yep! https://technet.microsoft.com/en-us/library/dn789066(v=exchg.150).aspx
Twitter!: Please Note: My Posts are provided “AS IS” without warranty of any kind, either expressed or implied.

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http://msdn.microsoft.com/en-us/library/cc280386.aspx
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Hi,
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(METHOD_DATA =
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HTH

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Hello all!
As of the last month or two, Firefox now crashes multiple times per day (even in Safe Mode). Firefox is fully updated, as are my Add-ons and Extensions.
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Windows 7 Home Premium
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"application": {
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Was discussed here - https://support.mozilla.org/en-US/forums/contributors/709022 - in Feb 2013. And Bug #738661 was filed in March of 2012, with the consensus being.
'''"In that case this is more likely a bug in Covenant Eyes than it is a bug in Firefox. If we have no hope of success through engaging with Covenant Eyes and can't blocklist the offending DLL from loading, can we at least get a support article posted instructing users how to work around this issue (ie. removing Covenant Eyes or switching to a different browser)?'''
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How can I connect to multiple Databases (using @PersistenceContext) using an EJB?
Did I need to connect various Entity Managers corresponding to the each database and simply send my Queries?
I am using Glassfish Application Server
Netbeans IDE
Java Derby Database
Oracle Database
Java Persistence API
Thanks in Advance

Yes, you need a persistence context and thus entity manager per database. Depending on what you want to achieve you may also need to go to the next level in your skill set and learn all about distributed transactions.

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I am tryiing to figure out the best way to implement my JE environment. My use case requires that I be able to use UNIX tools like 'cp' to move JE databases from place of generation (development) to place of consumption (production). Moreover, each JE database stores very different data and has different refresh cycles (ex., one of them may be refreshed every week, another may be refreshed once a month, etc.)
My dilemma is:
1)- Should I use one env w/multiple databases, or,
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Thanks

Hi,
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TNX!

BTW, that control panel also works to make OSX
selectable in OS's as early as OS 8.6.
Hello and Thank you for all the answers, esp. to Don for that really valuable information bit and to Kenichi Watanabe for taking the time and testing.
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Hi Experts
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I have 2 database servers (ServerA and ServerB) and want to create linked server on ServerB to link multiple databases on ServerA).
I have admin right on ServerB.
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Thanks.

EXEC sp_addlinkedserver 'ServerADB1', '', 'SQLNCLI', 'ServerA', @catalog = 'DB1'
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etc.
Please look up the details for sp_addlinkedserver as I typed this from memory.
I can certainly see a point in having one linked server per database, as then you don't have to hardcode the database name in the queries, and the linked-server definitions can be changed if the database name changes.
Erland Sommarskog, SQL Server MVP, [email protected]

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iMac goes to sleep/hibernate multiple times per day after installing Maverick OS. Moving the mouse or hitting the spcaebar will not wake the pc.
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Please read this whole message before doing anything.
This procedure is a diagnostic test. It’s unlikely to solve your problem. Don’t be disappointed when you find that nothing has changed after you complete it.
The purpose of the test is to determine whether the problem is caused by third-party software that loads automatically at startup or login, by a peripheral device, by a font conflict, or by corruption of the file system or of certain system caches.
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Hi All,
I have created an FR report (9.3x) and getting the below error while trying to run the report via Web Preview.
5217: Error Processing Results;hasPovDims=1;povXML=<?xml version="1.0"?><datasources><datasource name="FIN QA" dsid="-117fcde3_132fd17f2f6_-771b" allowEdit="1"><dim name="Versions" dimIndex="0" dsName="FIN QA" keyDimName="Versions" memberName="Versions" displayName="Versions: Versions"/><dim name="Scenarios" dimIndex="4" dsName="FIN QA" keyDimName="Scenarios" memberName="Scenarios" displayName="Scenarios: Scenarios"/><dim name="Components" dimIndex="5" dsName="FIN QA" keyDimName="Components" memberName="Components" displayName="Components: Components"/><dim name="Customers" dimIndex="6" dsName="FIN QA" keyDimName="Customers" memberName="Customers" displayName="Customers: Customers"/><dim name="Assets" dimIndex="7" dsName="FIN QA" keyDimName="Assets" memberName="Assets" displayName="Assets: Assets"/></datasource><datasource name="FINDEF QA" dsid="-607fb334_128b79d246e_-7d0a" allowEdit="1"><dim name="Time Periods" dimIndex="1" dsName="FINDEF QA" keyDimName="Time Periods" memberName="Time Periods" displayName="Time Periods: Time Periods"/><dim name="Scenario" dimIndex="3" dsName="FINDEF QA" keyDimName="Scenario" memberName="SC_Actual" displayName="Scenario: SC_Actual"/><dim name="Versions" dimIndex="4" dsName="FINDEF QA" keyDimName="Versions" memberName="VR_Input_Version" displayName="Versions: VR_Input_Version"/><dim name="Customers_Region" dimIndex="6" dsName="FINDEF QA" keyDimName="Customers_Region" memberName="CU_NA" displayName="Customers_Region: CU_NA"/><dim name="Assets" dimIndex="7" dsName="FINDEF QA" keyDimName="Assets" memberName="Assets_NA" displayName="Assets: Assets_NA"/></datasource></datasources>
In my report I have selected 2 rows where I have selected @descendants of ccounts from one database which is FIN QA and in the second row I have selected @children of Accounts from another database which is FINDEF QA. I am using only ONE GRID here.
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Please have your valuable inputs.

Yes it possible to retrive data from multiple database using single grid.
Also there are few limitations namely:
Database connections must be of the same type (for example, both must be Essbase database connections or both must be Financial Management database connections).
Mismatched number of dimensions in the database connections may cause retrieval errors.
For more details refer to this link for details:-
http://www.oracle.com/technetwork/middleware/financial-management/tutorials/obe-multipledbs-086586.html
Cheers
Vikas Naidu

Use 1 listener for multiple database in a server

hi guys,
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(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = ora03)(PORT = 1521))
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(GLOBAL_DBNAME = O11R2)
(ORACLE_HOME = /oracle/app/oracle/product/11.2.0/db_1)
(SID_NAME = O11R2)
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(GLOBAL_DBNAME = O10G)
(ORACLE_HOME = /oracle/app/oracle/product/10.2.0/db_1)
(SID_NAME = O10G)
)sorry i am reading about it so did not install another database to test out. Just thinking in the line that it mention that the list of SID is refering to the multiple database that is installed in a server and i am using 1 listener.
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Shivananda Rao wrote:
LISTENER =
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(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = ora03)(PORT = 1521))
SID_LIST_LISTENER =
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(ORACLE_HOME = /oracle/app/oracle/product/11.2.0/db_1)
(SID_NAME = O11R2)
(SID_DESC =
(GLOBAL_DBNAME = O10G)
(ORACLE_HOME = /oracle/app/oracle/product/10.2.0/db_1)
(SID_NAME = O10G)
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Multiple databases in one file: a small snafu

Hello everyone,
Opening multiple databases in a single file is an administrative convenience. It is well explained in the manual (see db/docs/ref/am/opensub.html). Normally, there is little difference between databases in their own physical files or grouped together in a single physical file. There is one small sentence in the manual that says the following:
(begin fragment)
However, since multiple databases in a file exist in a single physical file, opening two databases in the same file simultaneously requires locking be enabled unless all of the handles are read-only. As the locks for the two databases can only conflict during page allocation, this additional locking is unlikely to affect performance.
(end fragment).
I didn't pay attention to it, except the "unlikely to affect performance" part which told me that I wasn't to worry about it. The sun was shining. Life was good.
And I was wrong. It was one of those "epic bug quests" I had to embark on, only to realise that it may not be a BDB bug, but my carelessnes. Nevertheless, I'm left with an uneasy feeling which I would like to explain here.
Consider BDB configured as a concurrent data store.
There are 2 threads. The first thread has the following pseudocode:
cursor1 = db1->cursor(...)
while(cursor1->c_get(... DB_NEXT...))
// 1
cursor2 = db2->cursor(...)
while(cursor2->c_get(... DB_NEXT...))
The second thread does only the following:
db3->put(...)
db1, db2 and db3 are all distinct databases. All cursors are read-only (the cursor implicitly used in db3->put is of course a write cursor).
While the first thread is running, the second thread executes db3->put(...) at "//1".
Question: what happens?
Answer 1: if db1, db2 and db3 reside in different physical files, nothing special happens. Everything proceeds as it should.
Answer 2: if db1, db2 and db3 reside in the same physical file, both threads block "sometimes".
The "sometimes" used here means "when the put operation in thread 2 needs to allocate a new page".
Reading the BDB source code is extraordinarily difficult (which says more about my limitations than about the clarity of the code) but here is what happens, as far as I could determine:
(thread 1) cursor1 needs and acquires a read lock on db1
(thread 2) db3->put needs a write lock on db2 to allocate a new page. Since db2 is in the same physical file as db1 and thread 1 already has a read lock, thread 2 waits until the read lock is released. Thread 2 blocks.
(thread 1) cursor 2 needs a read lock on db3. For some reason, BDB detects that the another thread is waiting for a write lock on the physical file, and thread 1 blocks.
Both threads block waiting on each other to complete.
I suppose the system is the way it is to avoid starvation, but there you have it: be careful when you're lumping together multiple databases in one file!
Anyone who can clarify or confirm this is welcome.
Vincent

I had experienced a similar problem. I run multiple process. Each one of them starts a transaction that does db->put and db->pget to its own database (which also has a secondary index). When each database is in a separate physical file there is no problem but when I put all databases in a single file the processes start to dead-lock.
The following combination of options solved the deadlocking problem:
- use serializable isolation level instead of snapshot, i.e. do not pass DB_TXN_SNAPSHOT to txn_begin
- do not pass the DB_NO_WAIT option to txn_begin
- use Btree instead of a Hash
Hope that helps.

Can you have multiple databases on the same LUN in Exchange 2010?

I'm sure you can but is it possible with exchange 2010 to have multiple databases on the same LUN. We currently have 8 DB's all writing to their own DB drive and separate log drive so 16 drives in total. I need to spin a new DB up this week and
wanted to double check this is possible. I've looked online and cant find anything that I've seen before that says this is possible.
Thanks.

Hi,
Yes, multiple databases could be placed on the same LUN, but it's not recommended.
If you have 2 drives fail at the same time (it happens more than you think), then losing 100% of your DBs is a lot worse than losing one of them or some of them depending on where the failures are.
Here is a similar thread for your reference:
Multiple databases on the same LUN in Exchange 2010
Hope this helps!
Thanks.
Niko Cheng
TechNet Community Support

Multiple Databases per volume ??

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