iMac: Odd issue with my UPS

[Anonymous user]

Over the past few weeks I've been getting an error with my DuperDuper (backup software) scheduled backup. I am backing up an external FW drive to another external FW drive. The SuperDuper log would show "Error | GetMasterBlock: Error 5 from read; amount=-1, wanted=512". I did all the prerequisite cable swapping, replaced power supply, fix permissions, reformat drive, turn everything off and on, ran drive genius, etc ...

As a last resort, I unplugged the drive from the UPS (an APC Back UPS 750) and plugged it straight into another AC outlet. For three days it backed up flawlessly. Then last night I plugged it back into the UPS - and the problem came back.

I'm stumped as to why it would start doing this now. I've had this drive and UPS for over a year and this problem only started a few weeks ago.

Could the UPS not be providing enough power? Could the power be 'dirty'?

Thanks in advance.

[Anonymous user]

Ok. Backup last night didn't run either. I think something is messed up in the HD enclosure. I have three other FW drives, all plugged into the APC and they run fine.

[voidstar_apc]

Is the hard disk plugged into the "Controlled by master" outlets?

[Anonymous user]

SD support said "This generally means that one or more devices on the bus aren't responding properly when the mount points are refreshed. Try powering everything off and on... "

Which I've done numerous times.

I know the UPS works as I've been working during a power failure.

I know some of the outlets are supposed to provide power even when the computer goes into sleep mode. Thing is, my iMac never goes into sleep mode (just the monitor).

[BillP]

are you able to find out what the error means exactly from your other software? to me it seems like it is just unable to write 512 bytes of data for some reason. is that the case?

if so, are all of these drives always plugged into the UPS? is there any possible reason they could have turned off, thus then they would not be able to be writable?

have you seen the UPS run off the UPS while its on battery, successfully? i imagine so? i dont think it'd hurt to do a pull plug test while you are sitting in front of it though to make sure nothing is turning off that shouldnt, then causing the drive not to be able to be writable.

[Anonymous user]

Hi

google

Error | GetMasterBlock: Error 5 superduper

gives a number of post relating to various problems, which may assist

Also look in the console logs, and see if there are any clues there.

[Anonymous user]

I Googled that phrase and different versions of it but not finding anything that I haven't tried before.

Will try another AC outlet tonight.

As Holmes says ... "When you have eliminated the impossible, whatever remains, however improbable, must be the truth".

I know it doesn't make sense that it's the UPS causing the problem, but so far, whenever my HD is plugged into it, my backup doesn't run.

[Anonymous user]

I plugged into the "Controlled by Master" outlet last night and got the same problem.

[voidstar_apc]

Sorry if I was unclear: the hard disk shouldn't be on the controlled by master outlets. Since you tested that last night, I assume before they were on the Battery + Surge outlets and it didn't work? I guess the only thing left to test is the surge-only ones.

[Anonymous user · Accepted solution]

That's correct. For three nights it was plugged into one of the battery/surge outlets. So I've tried both on the APC.

Tonight I'm going to try a regular 'ol surge protected power bar that's plugged into the same outlet as the APC. The night the backup did work it was plugged into an outlet on the other side of the room.