pixelmagic Posted December 21, 2005 Report Share Posted December 21, 2005 I'm running Windows XP Pro (SP2), using Retrospect 6.5 (current driver installed) with a Sony SDX-700C AIT drive. Recently, I noticed that the content going to the drive is not compressing. After weeks of troubleshooting which include switching PCs, replacing the drive, switching SCSI cards and changing the OS (previously W2K when the problem started), I think I've narrowed it down to Retrospect being the problem. What happens is in Device Manager, the drive shows it is "functioning properly". As soon as Retrospect accesses the drive, the icon gets a red "X" over it and windows disables the device. The drive continues to run, but does not compress the data and stops at 100 GB. I saw the tech post about how SP2 can interfere with Retrospect but the problem described in that post has to do with Windows Firewall which is turned off on this computer. I'm at my wits end right now and I'm definitely not paying for tech support. Link to comment Share on other sites More sharing options...
natew Posted December 22, 2005 Report Share Posted December 22, 2005 Hi The Red X in device manger is normal. Retrospect has its own driver for the device. The windows drivers will interfere so they are disabled automatically. The amount of compression depends entirely on the type of data you are backing up. Some data compresses well. Other data does not. Also, tape manufacturers always quote the best case scenario for compression and capacity. You are lucky if you get native capacity +30%. There are some cases where you won't even get the native capacity of the tape. Keep in mind that Retrospect counts a Megabyte as 1024 bytes. Chances are the tape manufacturer considers a megabyte to be 1000 bytes. That adds up rather quickly... Thanks nate Link to comment Share on other sites More sharing options...
pixelmagic Posted December 22, 2005 Author Report Share Posted December 22, 2005 Thanks, that helps alot! However, the transfer rate seems really slow lately. For example, it takes about 24 hours to back up 65GB of files of various sizes. That seems excessive. Especially since a 120GB backup used to take about 12 hours. Sony had me test the drive for data transfer rate and determined that there was something wrong with it and sent me a new drive. The new drive does the same thing. I've switched SCSI cards as well. The info about the device manager really helps though. Thanks again! Link to comment Share on other sites More sharing options...
natew Posted December 27, 2005 Report Share Posted December 27, 2005 Hi A large number of small files will back up much slower than a few large files even if the total number of bytes is the same. The best way to benchmark is to disable compression and do a test backup with some 500MB+ files. That will give you a best case scenario for throughput. Thanks Nate Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.