A salutory tale
having just posted at length about backups, i now have to admin to one of my own failures. As said, I have a bunch of whopping great hard disks on which I store data. They are not RAID configured, just a bunch of disks.
i’ve had one disk which has been reporting an error (bad sectors) for a couple of years. it’s a small one with the operating system on it. i’ve been ignoring the errors as it hasn’t had much traffic and … well … it’s just worked anyway.
recently (oh yes) one of my other disks started dying and so i migrated the data from that on to the OS disk so that i could trash the dying drive and replace it. Of course the OS disk died just as I installed a new terabyte sized SATA monster into the free drive bay. So there goes 9 years of email achives, several thousand pounds of software images (i’ve probably still got the CD’s somewhere, perhaps [please!!]) and a bunch of other files that I can’t even remember! there goes too a bunch of digitised recorded movies (legal). I hadn’t backed this stuff up. My (very) bad. The disk drive will not even spin up: if i had to guess the power circuits are fried. i don’t dare a platter transplant.
So my solution will be to send the drive to OnTrack, which will cost me c £2k. and then i’ll buy another 3 terabyte disks and another box and set up two mirrored RAID disks in each box, establish one to take live backups from all my users and then get it to talk to the other once a day to mirror itself across to another location.
Does anyone have any recommendations on how to manage the mirroring? i don’t want a backup so much as a precise mirror of the data disks. but the transport layer will be TCP/IP over adsl – max 1MB/s outbound so i need to keep the bandwidth to a minimum using byte-aware backup apps.
I don’t have any mirroring tips to offer. I wonder if you had find a solution and may want to share it.
yes. for non-multimedia content I use a combination of windows live sync and dropbox. dropbox holds all of my live data (i.e. data that is prone to change relatively frequently) and windows live sync holds data that is likely to change only once a year.
multimedia content is synced from a master server onto a remote apple tv (hacked to extend it to 2TB). the syncing is very slow indeed but as i add only about a GB a week, the sync’ing happens over a couple of nights and transparently to the user. it’s not a perfect solution due to the weird naming system of apple tv content, but such is life. the bridge is made using a layer 2 (TAP) VPN connection using openvpn (remember the apple tv is hacked).
i also backup my laptop (which should be a reflection of the core data) via time machine every weekend.
the master server now has some big disks in (but see below) and is set up as a raid array.
one of my desktop disks fried last december, also a laptop disk. i bought a new disk for the laptop and left in connected to the time machine over night. but when it happened I was in another country so I just went along to the nearest apple store and bought a new laptop. with the remote services that i had set up (windows live sync and dropbox) i was able to get the other laptop up and running with all my data in under 30 minutes of work (then just left it syncing overnight). perfect solution.
the desktop was more trouble – i had no spare drives so ripped a raid participant out of the master server and shoved it in the iMac. then restored the computer from the time machine backup. this was (see above) the backup from my main laptop – but as the laptop and desktop should be mostly reflections of each other, no loss there. so I restored from time machine (very slow) and then used the live sync + dropbox combo to update it to bring it into full sync with the live data.
the great thing about this solution is that it’s all free (save the hardware for the time machine and master server). i don’t really need the time machine but it is one more layer of redundancy from the master server.