Drobo [Gen2, 4-Bay] and Time Machine Nightmare

I’m not a very technical person so I’ll describe this the best I can.
Issue One:
I’ve been trying for weeks to sort out why one of 3 Drobo volumes (Named Volume 1) either won’t mount on my Mac OS X 10.9.5 desktop unless I put the Drobo on standby, restart it, then re-start my Mac or it won’t show up on the desktop at all. Drobo Dashboard, Disk Warrior, Disk Utility SEE the disk. It took hours but I ran Disk Warrior and it reports the disk is in fine working order. Drobo Dashboard says all 4 internal drives are working fine and there is plenty of free space.

Issue Two:
Since I got the Drobo in about 2010 I’ve been using Time Machine to create backups. Along the way a drive or two failed, I replaced it, all was fine. No data loss, but…now Time Machine is complaining that there isn’t enough room to backup the data and that the Volume 1 Drobo is getting filled up. According to Drobo Dashboard, I had many free TB of space. I “thought” the Drobo was copying data across ALL the 4 drives in the bay, not just to Volume 1.

I thought it was my fault and that I should select Volume 1, 2, and 3 for Time Machine to write to, instead of only selecting what is named Volume 1, but what I see it doing is copying the entire internal hard drive I need backed up onto EACH VOLUME, one at a time, taking MANY HOURS to do so. I just know that if I have an HD failure and I yank out a drive I’m going to lose data. The DRobo is not copying across the volumes.

I cannot find information on how to set up Time Machine correctly with the Drobo. I can’t sort out what I did wrong and this has been a total nightmare. Like everyone else, I depend on my computer data and I can’t lose it and in the middle of all this my internal drive DID fail so I don’t know if that caused a problem with the Drobo (I have since gotten a new internal drive AND a bootable mirror drive for it).

Volume 1: HFS+ 2 TB (drobo dashboard says 1.43 TB used)
Volume 2: HFS+ 2 TB (drobo used to say not much was on the drive, since I changed the preferences in Time Machine and chose as a destination it now says 1.94 of 2 TB used)
Volume 3: HFS+ 2 TB (I cancelled the backup before it was done but it is showing over a TB of data on that volume)

Actual Drive Size:
Top Slot: 1 TB
Second Slot: 3 TB
Third Slot: 3 TB
Fourth Slot: 2 TB

Amount of data I need to back up: 1.5 TB TOTAL so in theory I should have PLENTY of free space on the Drobo. I now only have 881.48 GB Free, 5.44 TB used.

I am so frustrated. If someone can help me I will buy you lunch (if that’s allowed on this board) or I will name a kitten after you (I DO run a non-profit cat rescue) or both. HELP!

Sad in Sandy Hook

ooh a tasty lunch :slight_smile:
(just joking) i make a fresh coffee and post back some thoughts for you robin…

looking at your drive config, then your gen2 drobo is likely to be in single drive redundancy mode, and with the following drive setup:
1TB + 3TB + 3TB + 2TB = 9TB raw total capacity
9TB (-3TB for sdr; the equivalent size of 1 of your largest drives) = 6TB actual
6TB (*0.9 for usual filesystem overhead) = approx 5.4TB available.

with this in mind, it looks like your drive volumes, were originally set up to be 2TB max per volume. (that is ok in itself, and i have actually set up all of my drobos to use 2TB max volumes as well)
There could be a way for you to use larger max volumes, and possibly just make 1 very large volume (but that would require reformating the drobo and starting from scratch)…

If we continue as you are though, then drobo and dashboard would have taken that 5.4TB of available space, and created those 3 volumes for you. (the volumes are essentialy virtual, and any data that you put on any volume, is actually stored across the whole drobo in a way that is managed by drobo. also, each volume might show up in finder as having 2TB free each, but you would only have 5.4 or a bit less in reality, which is why is it good to see the total overall used, and free space for the whole drobo via dashboard)

Do you have any more info about what is the overall backup strategy that you want to achieve?
for example, are you having your main computer setup with a mirror raid, (so that your main computer and operating system can sustain a drive failing), which is a good feature…
but are you then also “only” using the drobo as storage, so that only time machine backups of the whole computer are backed up onto the drobo? or are you also storing other, extra copies of files, or other different data onto the drobo, as well?

any other info you have when you get a chance, including how you use the other volumes, would be cool and maybe other mac users can also add their thoughts too, as to be honest i only have windows and do not have time machine myself.

For your mounting issue, it might be a case of time machine possibly locking that volume, while it does its backup? how are your backups taking place robin, is it something that you manually click on to start it, or is it always happening all the time, or at a regular interval like every day at midnight or something?

there is a very good time machine website that another user posted, i belive john.m, and that might also provide some useful info or guides for you that could help in the meantime too:

If timemachine is trying to create a new (additional) 1.5TB backup, either as part of its backup (or as part of its proces before it deletes any older backup data or un-needed backup data), then based on your volume info above, i dont think it would have enough space to do that (which is why you have been getting those types of messages)

with this in mind, and if you are storing other extra data on your drobo as well, then maybe a way forward could be to try shuffling your standalone data files around, so that most of your standalone data is on volumes 2 and 3, and so that volume 1 is mainly empty for time machine to use… (by standalone, i mean the data that you know is just static data, such as pictures and pdfs or movie clips etc, that you have created and copied there, rather than moving folders around that have been created with, or are used by programs, as that can cause problems)

also, if your main computer operating system is currently with a working raid mirror, (and if the time machine backups are only backing up data from the main computer), then it might be worth cancelling time machine, and to essentially remove any existing timemachine backups from the drobo, and then letting the drobo have a bit of time overnight to settle as it optimises and reclaims the free space, and then to recreate a fresh time machine backup on the volume 1, after shuffling your data around to free up enough space on volume 1…

… however, before you start a fresh time machine backup, i think it would be good to have another look in dashboard, just to make sure that there is enough overall Free space on the drobo, as well as on the volume that time machine will use, plus a bit of forward planning to see how large your time machine backup requirement “could” become or grow into, because maybe your computer could end up having more then 1.5TB in a future backup, and there needs to be a careful consideration of this, to minimise the risk of timemachine overfilling your drobo…which is also why some of the newer models of drobo have a special time machine feature which dedicated a timemachine area for it.

(sorry for the long post robin, now you see why i needed a coffee :slight_smile:

btw there is also some more info available here about how the new drobo supports time machine, (as well as supporting DDR mode, which is a newer drobo feature that can help protect against any 2 hard drives failing, rather than just the 1 single sdr mode that the older models like yours has)

(about half way down)

a pdf link is there too which can be found here:

there is also a migration process which i believe can support migration of your current drobo diskpack drives, into a 5D for example with the migration process here:
(though probably good to mention plans before doing them if possible, so that everyone can offer thoughts and adivce for you)

[quote=“Paul, post:2, topic:143052”]
ooh a tasty lunch :slight_smile:
(just joking) i make a fresh coffee and post back some thoughts for you robin…

Thank you! Once I have tea, I will get back to you on this. :slight_smile: