Dexter Graphic wrote: > I will try it again tonight before bedtime. I figure it will take several > hours to duplicate my 40 GB drive. Which block size do you think I should > use to improve the speed? Is bigger better?
It should take 1-2 hours, if you have all the right hdparm settings. For my disk, these are the right settings. > tivopc oss/lm_sensors mips> # hdparm /dev/hdb > > /dev/hdb: > multcount = 16 (on) > I/O support = 1 (32-bit) > unmaskirq = 0 (off) > using_dma = 1 (on) > keepsettings = 0 (off) > nowerr = 0 (off) > readonly = 0 (off) > readahead = 8 (on) > geometry = 79780/16/63, sectors = 80418240, start = 0 You probably want the same, but maybe a different multcount. On Debian, see /usr/share/doc/hdparm/README.Debian for details. As for blocksize, medium sized is better. If the block size is too small, there's too much overhead. If the block size is too big, only one disk is active at a time. Most disks have a 2 Mbyte cache, and I'd suggest a block size half that big: 1 Mbyte. That way, /dev/hda should be able to run at full speed filling its cache, and /dev/hdb should be able to accept full write requests into its cache. It should/might keep both disks running at close to full speed. > Another thing that I am concerned about is how dd handles the occurrence > of unusable (marked bad) sectors on the target drive? Does this potential > shifting of block locations mess up the partition tables or file systems? Bad sectors are remapped in firmware. > And wouldn't it decreases the total capacity of the drive by a few blocks? Drives are a little bigger than advertised to compensate. > Does Linux support SMART? Um, I dunno. What's SMART? -- Bob Miller K<bob> kbobsoft software consulting http://kbobsoft.com [EMAIL PROTECTED] _______________________________________________ Eug-LUG mailing list [EMAIL PROTECTED] http://mailman.efn.org/cgi-bin/listinfo/eug-lug
