Posts Tagged ‘litespeed’

SQL Server Backup Compression vs. Quest Litespeed Engine

As more and more functionality is built into products like SQL Server it’s always worthwhile reviewing third-party tools and utilities when you’re considering an upgrade to see (a) if they’re still required and (b) if the tools themselves need to be upgraded.  With the introduction of Backup Compression in SQL Server 2008 R2 Standard Edition you could begin to think that the future is grim for Quest’s backup compression software LiteSpeed so I thought I’d do some testing to see exactly how it stacks up against the native compression.

LiteSpeed Engine

I’ve been using LiteSpeed on and off for a few years now and it has always been a great tool but I’ve always found it a bit of a drag to have to use the GUI to administer and setup jobs however in January 2010 Quest launched the LiteSpeed Engine for SQL Server which allows you to administer jobs using the native SQL Server tools.  The LiteSpeed Engine acts as a driver and the configuration tool allows you to define a variety of configuration profiles based on file extension and from that point onwards you can use the Management Studio to setup backup jobs, maintenance plans, etc. and all you have to do is specify the file extension of the profile you wish to use.

The configuration tool allows you specify the compression level from 1 to 8, encryption level including various bit-length versions of RC2, RC4, 3DES and AES though as you’ll see later the overhead of adding the highest level (256-bit AES) isn’t that great so I’d always shoot for the maximum.

Benchmark Structure

The test is relatively unscientific since I used only one database but it was carried out systematically, the data comes from a transactional billing system which I chose as it has a mix of strucured tables and raw transactions and comes in at about 6.5GB so it wouldn’t take too long to test.  I used the following configurations…

Benchmark Results

On my test database the baseline SQL Server native compression reduced the 6.2GB database to 765MB (12.2% of the original size) and took less than half the time (43%), to achieve the same level of compression using LiteSpeed I had to use Level 2 which gave me 12.2% of the original size and 40% of the original duration.

At first this doesn’t look great for the third-party tool but the benefit of using a mature backup compression engine is the flexibility and LiteSpeed’s configurations allow you to tweak the performance to solve whatever problem you have in your environment whether that be the absolute size of the backup, the backup window time or a mixture of the two.

If it’s size you’re after then Level 8 really did seem to work wonders on my test DB bringing the size down to 5.6% of the original at only 352MB though it did take 2.6 times the original duration, if it’s the backup window you’re looking to reduce then the basic Level 1 did manage to improve on the native compression by taking 0nly 37% of the original duration whilst still compressing to 13% of the original size.  If like most people you’re looking to have your cake and eat it (i.e. reducing size and backup window) I’d suggest that Level 3 is the best compromise giving 10.9% of the original size at 77% of the original duration so you get some benefit in both areas, though Level 4 takes compression a bit further and still gave a slight time reduction.

Clearly, the real answer is testing and since I’m at the beginning of data warehousing project I’m not in the position to make any firm decisions but I think that even if you don’t run out and purchase it now LiteSpeed is a very valuable tool to have in your mental arsenal so that if you come up against backup size/window issues or you’re faced with older versions of SQL Server you’ve got a solution in mind already.  Quest have an odd policy of keeping pricing quite opaque but I believe that the full Enterprise version (including the LiteSpeed Engine) retails for around £1,800 ($2,800) which isn’t too bad if you need that level of flexibility.

SQL Server Native Compression

LiteSpeed Compression (No Encryption)

LiteSpeed Compression (With Encryption)

Enable Backup Compression as Default in SQL Server 2008 R2

Of all the features added to SQL Server over the past few years I was particularly pleased with the addition of backup compression, there have been third-party tools around for a while that have done this (such as Quest’s excellent Litespeed) but third-party tools always add an extra layer of admin and maintenance that as a DBA I could do without. In SQL Server 2008 it was made available for Enterprise licences only but with the launch of SQL Server 2008 R2 backup compression is now available with a Standard license, though in both cases the feature is turned off as a default – so how do you use it?

Well, if you’re making a backup from Management Studio you can specify manually on the Options page of the “Back Up Database” page (right-click on DB >> Tasks >> Backup), like so…

Alternatively, if you’re one of the “Real DBAs don’t use GUIs” crowd you can add the “WITH COMPRESSION” option to the BACKUP command..

BACKUP DATABASE reportserver TO disk = ‘E:\ReportServer.bak’
WITH COMPRESSION

Or, conversely you can specify not to use compression…

BACKUP DATABASE reportserver TO disk = ‘E:\ReportServer_no_compression.bak’
WITH NO_COMPRESSION

But what if you want to use compression but don’t want to have to think about it every time – or more importantly, don’t want your users to have to think about it? To enable backup compression as a server-wide default you will need to use sp_configure…

USE MASTER;
GO
EXEC sp_configure ‘backup compression default’,’1′;
RECONFIGURE WITH OVERRIDE;

Now all you need to do is tell your storage admin that he/she owes you a drink!