jwcolby
jwcolby at colbyconsulting.com
Sun Dec 2 19:28:01 CST 2012
VHDs have been around forever. Back in 1990 I went for work as the (entire) test department for Stack Electronics, maker of Stacker data compression. The way that Stacker worked was to create a file which was mounted as a disk and then the driver wrote / read from the disk performing the compression as it did so. Obviously there is a performance hit as you manipulate the structures in the file to make it look like a disk however today we have so much processor power that the overhead is down in the mud. Look at compression in SQL Server, where they store compressed data in SQL Server objects - tables and indexes. It is actually read into memory in compressed form and then uncompressed as it is used. Yea, it uses processor power but the average server often just cruises along mostly unused. Is the average Windows 7 desktop user going to notice the overhead of reading and writing to a virtual disk? John W. Colby Colby Consulting Reality is what refuses to go away when you do not believe in it On 12/2/2012 6:15 PM, Salakhetdinov Shamil wrote: > > Hi All -- > > Do you use Virtual Hard Disks on real computers and on VMs as e.g. it is described in the following article: > > "Create and Use a Virtual Hard Disk on Windows 7" > http://technet.microsoft.com/en-us/magazine/ee872416.aspx > > ? > > I wonder wouldn't using virtual hard disks result in some (significant) performance hits especially when virtual hard disks will be shared on host computer to use them from VMs via "Map Network Drive" feature? > > Thank you. > > -- Shamil > _______________________________________________ > dba-VB mailing list > dba-VB at databaseadvisors.com > http://databaseadvisors.com/mailman/listinfo/dba-vb > http://www.databaseadvisors.com >