dd or dd_rescue copies of SSD's are fine and no problem. The controllers hide all the fancy wear levelling stuff from the computer and present a disk that to the OS looks just line any other sata hard disk.
dd_rescue is a variant of the linux dd utility which can deal with disks that ate not 100% healthy see http://www.garloff.de/kurt/linux/ddrescue/ you will find dd and dd_rescue along with a bunch of other useful tools for copying partitions/disks on the knoppix distribution which is a bootable 'live cd' or can be used from a USB stick http://knoppix.net/ Trinity rescue kit is supposed to be very good too http://trinityhome.org/Home/index.php?wpid=1&front_id=12 On Tue, 2012-05-22 at 15:03 -0700, Jack Brindle wrote: > John; > > Be very careful with a sector-by-sector backup utility if you decide > to use an SSD. Solid State Drives constantly are moving sector > locations around in order to avoid writing to the same flash location > too many times. This occurs whenever a file needs to be updated or > rewritten, and is especially true of the directory sectors. Because of > this a backup may catch a file relocation in mid move, or more often > catch a directory update while it is being moved, The result will be a > completely useless backup. We discovered this recently when a friend > needed to restore his system from a backup. > > The answer is to use a normal file-oriented backup instead of a sector- > by-sector backup. Those backups are very much useful when needed. With > the trend to replace disks with SSDs, especially in laptops, this will > become very important. > > For those wondering, TIme Machine is indeed a file backup and not > sector-by-sector. I recommend it whole heartedly! > > Jack Brindle, W6FB > > > On May 22, 2012, at 11:22 AM, John Ragle wrote: > > > Hi, Jim... > > > > There are several programs that make literal copies (mirror > > copies) > > of disk contents. This includes the OS and all program files as well > > as > > data... > > > > I happen to have been using one called "Macrium Reflect > > Professional" for the last few years. It produces a bit-for-bit > > literal > > image (a mirror copy) of the TOTAL contents of one or more hard > > drives, > > and can re-load such images. It does much more than copy data files. > > At > > present, I am using a PC with 2 inboard hard drives, each of 250 GB > > capacity. One of these is my WIN7 Ultimate OS and associated files > > (including programs, etc), and is about 80 GB in total content. The > > second is my Ubuntu 11.10 OS and a somewhat smaller collection of > > files > > (including programs, etc.) I back up the former almost daily onto a > > 1 TB > > external USB hard drive, and somewhat less frequently onto a Sandisk > > 64 > > GB stick...the 80 GB on the C:\ drive fit nicely onto the 64 GB stick > > with the compression used by Macrium. The rate-determining step in > > these > > USB-based devices is the USB transfer rate itself; 80 GB takes about > > 25 > > minutes to back or restore, and I do it last thing at night, letting > > Macrium close down the PC when finished. > > > > If I had a third drive bay, I would probably choose to back up > > onto > > a third drive...hard drives have become so inexpensive that you can > > practically use them like floppy drives. This would be significantly > > faster, about 10-12 minutes for the 80 GB contents of C:\ > > > > A while ago, I used a Sparc 20 with a shoebox tape drive and "DAT > > Tapes," but that had little to do with my ham radio operation. These > > were unsatisfactory because the error rate was significant. I also > > tried > > using an elderly PC as a network server at home on our LAN. That too > > was > > somewhat cumbersome. My wife is an active software developer (vide the > > "OWL" system from Cengage), and separately uses a version of Macrium > > onto a 1 TB external drive, but much of her work is stored on a > > corporate "cloud," and hopefully backed up there as well. > > > > I do not have a high opinion of "Windows Restore" -- it is > > significantly more involved to use than is Macrium Reflect. > > > > An advantage (to me the most significant one) of doing a bit-image > > backup is that when it comes time to restore program files (i.e. .exe > > files, etc), one does not have to search out the distribution media > > and > > play "baking cookies" with those media for hours to rebuild the > > system. > > > > A disadvantage of doing a bit-image backup is that in the absence > > of good "garbage collection" one keeps using the same general > > structure > > over and over again...a case can be made for rebuilding from scratch > > (not from the bit image) on a regular basis...some have suggested > > once a > > year, at least. > > > > The Linux crowd can tell you of several useful Linux based > > utilities for total backup, restore, partitioning, etc...I won't > > enumerate them here, though many of them are very useful. > > > > In general, I don't favor running anything off the "cloud." My ISP > > is sometimes down for 1 or more hours, and that mode of dis-operation > > would leave me in the cold. Moreover, in view of the spate of > > successful > > hacking attacks, I don't trust cloud security. If I disconnect from > > the > > internet, the only ways someone can hack me are via my WiFi or to > > physically break into my home. I have taken pains to barricade the > > former. The latter takes care of itself in the usual way. > > > > Hope this answers your questions.... > > > > John Ragle -- W1ZI > > > > ===== > > > > On 5/22/2012 12:59 PM, James Robbins wrote: > >> John, > >> > >> > >> > >> Could you be more specific about your process for "bit image > >> backup" and > >> "safe sectors"? Program you use? What files you choose to > >> backup? Whether > >> Windows Restore program is or is not a suitable substitute? Thanks. > >> > >> > >> > >> 73, > >> > >> Jim Robbins > >> > >> N1JR > >> > >> > >> > >> "It is vitally important to practice "safe sectors." A bit image > >> backup > >> takes only a few minutes, and can be made on an auxiliary hard > >> drive or a > >> jump drive." > >> > >> ______________________________________________________________ > >> Elecraft mailing list > >> Home: http://mailman.qth.net/mailman/listinfo/elecraft > >> Help: http://mailman.qth.net/mmfaq.htm > >> Post: mailto:[email protected] > >> > >> This list hosted by: http://www.qsl.net > >> Please help support this email list: http://www.qsl.net/donate.html > >> > >> > >> > > > > -- > > Sent from my lovely old Dell XPS 420 > > > > ______________________________________________________________ > > Elecraft mailing list > > Home: http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/mmfaq.htm > > Post: mailto:[email protected] > > > > This list hosted by: http://www.qsl.net > > Please help support this email list: http://www.qsl.net/donate.html > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html -- 73 Brendan EI6IZ ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
