The Virtual Center Datastore

In the short six weeks that I have worked at VMWare I have already notice a number of cases revolving around database issues. Database connectivity, connections dropping, transaction logs filling. You might wonder why we have database issues with a virtualization product?

Virtual Center is the central peice that binds Virtual Infrastructure 3 together. To manage the tasks that it needs to do it required a robust datastore. The designers chose two Enterprise databases, MS SQL Server, and Oracle. No others are supported at this time (VMware ships with the MSDE database for testing purposes but is not supported in production environments).

I just came across another blog noting a database issue

It turns out that the machine we picked (a dev db) runs out of space
because our DBA’s don’t pay attention to their backup schedules. I am
making an assumption there but it has happened twice in a week and a
half. Well when the server runs out of space, there goes virtual center.

This sounds like one of these-

[2007-02-06 17:26:00.118 'App' 3376 error] "ODBC error: (42000) -
[Microsoft][ODBC SQL Server Driver][SQL Server]The log file for database 'VMware
VirtualCenter' is full. Back up the transaction log for the database to free up
some log space." is returned when executing SQL statement "UPDATE VPX_LOCK SET
ID = 0"

for which I suggest you do something along these lines-

C:>osql -E -D "VMware VirtualCenter"

1> backup log vcdb to disk = 'c:vcdb_log.bak' 

2 >go 

1> backup database vcdb to disk = 'c:vcdb.bak' 

2> go

-----------------------------------------

The result should look like this :

Processed 696 pages for database 'vcdb', file 'VCDB_dat' on file 1.
Processed 1 pages for database 'vcdb', file 'VCDB_log' on file 1.
BACKUP DATABASE successfully processed 697 pages in
3.112 seconds (1.832MB/sec).

There’s a lesson to be learned here. Don’t forget the backend: it can take your system down! You need to understand peices involved and how they can fail. If you leave it to some over-worked DBA you may be in for a surprise.

Technorati Tags: ESX, Server, VMware, Oracle, MS SQL Server, Database

***this doesn’t work for some I have heard, so here is another method-

Login to SQL Server, Open Query Analyzer:
(change pubs_log to databasename_log, pubs to databasename)
——————————————————————————–
1. DBCC SHRINKFILE(pubs_log, 2)
2. BACKUP LOG pubs WITH TRUNCATE_ONLY
3. DBCC SHRINKFILE(pubs_log,2)

4 thoughts on “The Virtual Center Datastore”

  1. VMWare has many bloggers. In fact, my blog is listed along side theirs here-
    http://www.vmware.com/vmtn/planet/v12n/

    Down on the right-hand side under VMWARE BLOGS.

    Don’t get me wrong, there is a company policy regarding employees blogging, but I have read the document and am adhering to it.

    Thanks for the concern.

  2. VMware is fine with its technical employees blogging about the product, since in general that leads to more communication with our users, better feedback, and therefore better products and more successful happy customers. vmwarewolf doesn’t speak for the company, and his words are his own, just as if he was speaking informally to friends or colleagues at a cocktail party or a conference.

    This post, for instance, raises the awareness of VirtualCenter and gives a common-sense heads up that, for any database-driven piece of software, you also have to, well, take care of the database.

    Now implying that DBA’s are lazy, well, that I can’t defend. :-)

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