Hi Rick, On Tue, 27 Mar 2018 23:04:33 -0700 Larry Colen wrote: > >>Two of my three external hard drives aren't working: One has an irreparably >>damaged partition map,
Irreparable by what, 'Disk Utiliy' ? Do you know what filesystem was used, was it HFS (macOS specific) or perhaps simply FAT32? >and another (my main external drive) has its light blink for a few seconds and >click, but doesn't show up at all. Does not show up in the Finder I guess, but not in Disk Utility either? The Finder will not see it if there is no mountable filesystem found, perhaps due to damaged partition tables, it is quite possible that the Disk Utilty still sees it, meaning the USB connection and drive are at least working. >>Could the crashing i/o card on the old Mini have damaged these drives? Is >>there any way to repair the one that's not showing up at all? Hard to say without further analysis, if it does not show up ANYWHERE (Disk Utility, other disk-tools) then it is likely to be a problem with the disk hardware, or perhaps the USB-enclosure ... >My guess is that they are USB drives? Spinny drives? > >Are they powered from the wall or over the USB cable? > >Can the drives be removed from their case and read directly as SATA drives? Good suggestion, but not so easily done. Not sure if the mac-mini has extra SATA ports ? (I have only used and older iMac and a 2013 macBook pro sofar, so not familiar with it) >I haven't done that level of programming on USB and/or hard drives, but while >I could see a partition map being splattered by random writes, it's hard to >imagine physical damage to hard drive itself. Indeed. Partition tables (MBR, and parts of GPT ones too) are close to the start of the disk, and that is the most likely area to get damaged when programs go astray ... >Something like this and some good disk recovery software might solve your >issues: >http://www.kingwin.com/storage/docking-stations/ezd-2535/ Indeed, I have a similar one ... >Or just move the hard drives to different cases and see if a different >USB<->SATA controller does a better job. > >In the short term, get another external drive so you don't mess things up >irreperably. Yes, good advice. If the data on the drives is valuable at all (meaning no other backups) you should make a copy (clone) of the disk, then attempt repair or file recovery from that copy ... >To be extra safe, you could try getting a couple of docks/cases, then maybe >use dd to make a direct copy of your old drive to your new drive, then try to >repair the partition table on the new drive. Right, with chances of the drives being damaged, perhaps use 'ddrescue' instead (to be downloaded, use google) If you are somewhat comfortable using the commandline, you could also try my own multiplatform disk-tool that can do an analysis of the disk, and search for missing partitions (MGR or GPT style) using the 'Analyse disks for support' menu item in the 'scripts' menu. It is text-mode, and runs in the macOS Console, but DOES have a menu system. I have assisted in dozens of partition-recoveries over the years using this tool. You need to install it from a ZIP-archive, then run a 'setup' script to set the permissions right, and create some symlinks and then run it with ROOT privileges (for example by using 'sudo') which will be done automatically if you use the 'dfs' symlinked script. You can download the installation ZIP from my website: https://www.dfsee.com/dfsee/download.php Make sure to read the '/doc/dfsinst.txt' from that archive for further installation tips, look for the Linux/OS-X section. I'll be available for further assistance if you choose to go this route ... Regards, JvW ------------------------------------------------------------------ Jan van Wijk; http://www.dfsee.com Flickr : jvw_pentax -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
