hi yup i try to read each new post on the whole boards and sometimes i miss a post or two.
(though am sure everyone wouldnt mind missing a post or two if it was spam etc)
i think the key concept is from my first reply which just to paste it here is this:
“for the volume size, i believe once you select a max size per volume, it can not be changed (without backing up and reformatting etc)”
what might be a bit confusing (and it is something that doccrhis helped me to understand when i first got my 1st drobo), is that all hard drives that we put into it, (either into an empty slot, or from upgrading a smaller drive into a bigger), simply all get added to the drobos total RAW capacity.
the raw capacity (using whole numbers for simplicity, such as in TB), is then used to capculate your actual USABLE space for data. This is based upon SDR or (DDR) protection, which subtracts 1 (or 2) of your largest hard drive sizes, and then the filesystem formatting eats up a little bit of space, which is why i usually take the remaining USABLE capacity and multiply it by 0.9
This ends up with the ACTUAL drobo capacity which is usable for data, and this is where the max volume size comes into play. So if (for example) the ACTUAL usable space was 3tb, and your max volume size that you selected was 2tb, then all volumes will only show themselves to the operating system as 2tb, and you would have 2 volumes (showing 2tb free space each) but you would only be able to utilise 3tb of data across them, eg 2tb in the 1st, and 1tb in the 2nd, or something proportionally similar).
so if i use one of my own gen1 experiences as an example, then what this essentially means, is that when i had 4x 1tb drives, and when i upgraded 1 of them from 1tb into 1.5tb, i “did not” actually gain any usable space it might have taken a 2nd post or email from docchris back then for me to understand, as the initial expectation was that my usable space would jump up by half a tb
this was my experience with DAS models, (as i think some NAS models have variable settings but only get a NAS model if you really need it, i like the das ones) but i hope this helps a bit, but please feel free to ask more quesitons if you need.
for johns question about volume size, please find some more info below for you john:
i have posted a fair few times in the past about this (and hopefully i wont forget one of the pros) but there are always pros and cons about having smaller max volume sizes, and ultimately its down to each user as to their preference, though for me, the main pros are these:
- easier for me to manage, and sync for backups etc
- works with XP (some computers or devices can only read 2tb max per volume)
- quicker chkdsks per volume (eg if computer crashes, i run a chkdsk on all volumes but one at a time, some take time but this way i can run some inbetween other actions, and can also set some to run overnight etc)
- quicker full virus scans per volume (similar)
- quicker full content indexing via “cathy” by r vasicek (a great windows tool)
- quicker boot times reported by other users (rather than having 1 huge 16tb volume)
and only downside for me is that each volume eats up a drive letter, but there are still plenty available