www.aiscl.co.uk

One thing I find a bit annoying is when I attempt to do a new session backup and I find that the disc runs out of space halfway through the backup. I find myself having to abort and then reset the backup, put in a blank CD, make a full backup on the new CD, erase the original CD, reset the backup again, perform another full backup on the original (now blank) CD and then finally, erase the temporary backup on the extra CD. If AIS Backup could check to see if the existing CD had enough free space before starting a session backup and then offer choices such as making another full backup on a new CD, it would be helpful (to me at least).

AISBackup has been designed to continue a backup on a new blank CD, it numbers the CD’s sequentially so that AISBackup can ask for the appropriate CD during a restore. AISBackup uses zip file compression so it cannot accurately determine the logical free space. Why don’t you use the disc spanning capability of AISBackup?

Barry

Barry wrote:AISBackup has been designed to continue a backup on a new blank CD, it numbers the CD’s sequentially so that AISBackup can ask for the appropriate CD during a restore. AISBackup uses zip file compression so it cannot accurately determine the logical free space. Why don’t you use the disc spanning capability of AISBackup?

Barry

Hi Barry

I do use the disc spanning feature for larger backup sets, but my main backup occupies much less than one CD and when a new session is being started, there is no way for me to know whether to try to fit it on to the existing CD or erase the CD, reset the backup and then start with newly-erased CD. It's only when AIS Backup asks me to insert another CD that I realise I need to reset the backup and start afresh.

Would displaying the free space on the loaded CD form help?

Barry wrote:Would displaying the free space on the loaded CD form help?

I think it would be a definite step in the right direction.

From build 223 the disc free space is displayed on the load disc form for pre-used media.

Barry

Barry wrote:From build 223 the disc free space is displayed on the load disc form for pre-used media.

Barry

This is a lot more helpful. If an approximation of how much space the intended backup would use it would be even more useful or else both options could perhaps be replaced with suitable text (e.g., "The backup you are about to run should fit on the loaded disc" or "The backup you are about to run will probably not fit on the loaded disc" or "The backup you are about to run will definitely not fit on the loaded disc"

I have run a few tests and the approximate compression is going to be about +-5% accurate (unless no compression is used). This is based on the average compression ratio based on the file extension. AISBackup will continue to compute the average compression ratio per file type, so this may get better over time. Because of the vastly different media types AISBackup will display the approximate backup size on the first load media form, along with the free space.

The approximation maybe better for some files types as the 5% was based on a 47GB backup of a multi-boot multi-operating system PC.

This option is also useful for disk based backups as possible disk full warnings can be given prior to the backup.

Barry

Version 2.0 beta of AISBackup has been uploaded. 2.0 contains an approximate size of backup which may help with your disc usage.

The actual size of backup cannot be determined and the figure is based on the average compression of file types split by small, medium and large file size.

If we get too much negative feedback about the accuracy we'll probably remove this feature.

Barry