iMac external HDD becomes uneditable

[dhartsough]

I have a 2010 iMac running OS X 10.11.6 with two External hard drives daisy chained via firewire. The second disk in the chain (4 Tb G Drive) is fine after a reboot - meaning I can edit files on it, However, after a couple of days something changes and I can no longer edit files on this drive. The drive and file permissions still show everything as read / write enabled, but I cannot actually save changes. Has anyone else seen this sort of problem and is there a configuration setting somewhere that can keep this from happening. Thanks in advance for any help.

 

[harryb2448]

G'day and welcome to the forums.

Select that drive in Disk utiity and run Disk First Aid and see what is reported.

 

[Randy B. Singer]

I have a 2010 iMac running OS X 10.11.6 with two External hard drives daisy chained via firewire. The second disk in the chain (4 Tb G Drive) is fine after a reboot - meaning I can edit files on it, However, after a couple of days something changes and I can no longer edit files on this drive. The drive and file permissions still show everything as read / write enabled, but I cannot actually save changes. Has anyone else seen this sort of problem and is there a configuration setting somewhere that can keep this from happening. Thanks in advance for any help.

Try this:

Shut down your Mac and turn off both drives. Disconnect both drives.

Reconnect one drive only. Turn the drive on and then restart your Mac. See if everything is normal.

Repeat, only this time disconnect the first drive and only connect the other drive.

If everything is okay in both tests, my guess is that you are having signal reflection problems somewhere along the line. Try replacing your Firewire cables and/or trying a different Firewire port.

You can also try checking your drives' health with this free product:

DriveDX - free demo
http://binaryfruit.com/drivedx

 

[pm-r]

As Randy has already suggested, I'd agree that either one of the FW cables is goofy, but I'd suggest that more likely its one of the drive's FW ports that's gone a bit goofy and will probably fail completely in the near future.

The otter possibility is that the goofy drive is actually failing. A very likely situation if the drive is several years old.





- Patrick
======

 

[dhartsough]

G'day and welcome to the forums.

Select that drive in Disk utiity and run Disk First Aid and see what is reported.

I'll have to wait until the problem recurs, but from prior experience both Disk Utility and Disk Warrior exit with a message that they cannot unmount the volume to run the diagnostics. However, after a system reboot, all is good again.

 

[ferrarr]

If you restart, when you get to your desktop, try running either Disk Warrior or Disk Utility before doing anything else. Make sure any app that accesses those drives are not running first.

 

[dhartsough]

If you restart, when you get to your desktop, try running either Disk Warrior or Disk Utility before doing anything else. Make sure any app that accesses those drives are not running first.

I have run each of those multiple times following reboots. Neither has really discovered anything of significance. It is very odd as the disk is writeable for the first day or two following reboot, but then it stops allowing writes. I thought at one point it had to do with the fact that Time Machine wrote to this disk, but turning that off made no difference.

 

[ferrarr]

How are the drives formatted?

 

[dhartsough]

How are the drives formatted?

Both drives are formatted as: "Mac OS Extended (Journaled)"

 

[ferrarr]

Do you have the issue using Finder to copy files to the drive, or just when using an app? Are you saving new files, or re-saving a file you just worked on?

 

[dhartsough]

Do you have the issue using Finder to copy files to the drive, or just when using an app? Are you saving new files, or re-saving a file you just worked on?

The issue arises with anything that requires writing data to the drive: copying files, opening a text file with vi from the terminal and attempting to change and save a file, or using an application to change and save a file.

 

[chscag]

Have you tried what was suggested by Randy in post # 3? Daisy chaining firewire drives has always been a hit and miss operation due to flakey cables, etc. Same problem that used to occur with daisy chained SCSI drives back in the old days.