On 02/16/2011 05:44 PM, Simon Mcnair wrote: > I just went to bed and one last question popped in to my mind. Since > there is a fair timezone gap I thought I'd be presumptuous and ask it > in the hope I can turn it around a bit quicker in the morning. > > My suspicion is that once I have 5 formatted 2tb drives I may be lucky > to get 10x 1tb dd images on to it. Can I feed the dd process in to > tar, bzip2, zip or something else which will give me enough space to > fit the images on ? > > Will I get more usable space from 5x2tb partitions or from 1xspanned > volume ? (the thecus pretty much only allows you to create raid > volumes so a jbod needs to be 5x1tb arrays or 1 spanned volume or > stripe). I'd use one spanned volume, and gzip. I'd simultaneously generate an md5sum while streaming to your thecus. A script like so: #! /bin/bash # function usage() { printf "Usage:\n\t%s devname\n\n" "`basename \"$0\"`" printf "'devname' must be a relative path in /dev/ to the desired block device.\n" exit 1 } # Verify the supplied name is a device test -b "/dev/$1" || usage # Convert path separators and spaces into dashes outfile="`echo \"$1\" |sed -r -e 's:[ /]+:-:g'`" # Create a side-stream for computing the MD5 of the data read fifo=`mktemp -u` mkfifo $fifo || exit md5sum -b <$fifo >/mnt/thecus/$outfile.md5 & # Read the device and compress it dd if="/dev/$1" bs=1M | tee 2>$fifo | gzip >/mnt/thecus/$outfile.gz # Wait for the background task to close wait -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html