4 ms·

This is a good time to remind people about proper backups: the 3-2-1 rule. 3 backups. 2 backups (or more) should be on different mediums. 1 (at least) should b

by cdumler 11y ago

This is a good time to remind people about proper backups: the 3-2-1 rule. 3 backups. 2 backups (or more) should be on different mediums. 1 (at least) should be offsite (ie. home copy at work or in the cloud) You need three backups. If we assume that every copy has a chance small but real chance of failure, the chance of all failing at once becomes exponentially less with each copy. You need at least two different systems (media) for backup to reduce the possibly that one of them appears to be backing things up, but is in fact corrupted. So, two of some system, like Time Machine, Carbonite, Backblaze, Arq, rsync, etc. Ideally, you need to be able to verify your backups. Backups that stores things as files means you can periodically try pulling down some files to make sure they're good. Cloud backups should be in the mix, but consider them last resort for restoration as they are usually pretty difficult to verify everything is good. You need one offsite to prevent your house burns down and takes your machines and local backups. You can do this with physical media rotation (ie. have two machine backups swapping places with home and work) or have a backup to the cloud.

dozzie 11y ago
There is this joke that you need three, in case your second one is damaged, because the first one will be damaged for sure. I heard it in form about lighters in survival.
hga 11y ago
I like to say that if you have 1 copy, you have none. If 2, 1, if 3, you have 2 copies, the absolute minimum. And try to decrease single points of failure, e.g. I use rsync for rsync.net and BackupPC to local disk, and tar to LTO tape after giving up on the opaque and baroque Bacula. You need one offsite to prevent your house burns down and takes your machines and local backups. I'm a long term fan of tape, from the first time I used UNIX(TM) in 1978 and a DECTape saved me when I was learning the power of the -rf flags to rm. LTO tape systems for the home are not insanely expensive (then again, this is my minimum system today: https://news.ycombinator.com/item?id=10483361 https://news.ycombinator.com/item?id=10483361 ECC is a requirement for me). Street price for the HP LTO-4 internal SAS EH919SB I'm currently using is ~1,300 USD (and it wasn't difficult to get it at around that price in 2011). Add a LSI 2004 chip based SAS-2 controller such as the "Avago" LSI 9211-4i at $167 from Newegg right now to drive it, and a semi-disposable flash drive to feed it quickly so the tape doesn't "shoe shine" (the tape moves very quickly, if you don't feed it quickly enough it has to stop the tape and backup enough so that it's at speed when it starts forward again and hits the location where it ran out). I.e. at whatever speed write a 10GiB slice of your backup to the flash drive, then write that all at once to the tape. Considering media costs, if you start from scratch today you'd probably be better off going LTO-5 now that LTO-6 is shipping, the media costs the same as for LTO-4 despite a near doubling of capacity. I've got enough LTO-4 tapes that I'll keep using them until my LTO-4 drive dies, then buy an LTO-5 drive, which per the standard can read two earlier generations, and write 1 earlier, and new LTO-5 media for it. Current LTO-4 and LTO-5 tapes from HP or Fuji (I wouldn't trust anyone else) go for $22-23, uncompressed capacities are 800 and 1.5 GB respectively. And then store copies off-site, and copy your most important stuff at least once a day to a site like rsync.net, which saved me when a tornado trashed my apartment in 2011.
- bboreham 11y ago
  > Current LTO-4 and LTO-5 tapes [...] go for $22-23, uncompressed capacities are 800 and 1.5 GB respectively. I think you meant 1.5TB. However, why not just use hard disk drives at just over twice that price? You'd get quite a lot of them for the cost of the tape drive.
  - hga 11y ago
    Because tapes are much less fragile than hard disks, and I can stash a bunch of tapes in my safe deposit box and other places. As well as have many copies of my data as I keep monthly full backups for at least a year. And, hmmm, my tapes as I use them are more reliable than my Seagate enterprise disks, and that's with the latter not moving around (i.e. in all my post-mid-2011 tornado hardware, I've had two disk failures and no tape failures). For the level of data security I want, and the tiny AT&T DSL straw I'm currently forced to use, even with things like Amazon Snowball and ever lower prices on "nearline" cloud storage, if a tape drive lasts long enough, the numbers work better for tape. And compared to the usual enterprise, I don't beat up on tape drives, they're over-engineered for my duty cycle. I also have a desire to be able to make due without monthly charges, which a cloud solution doesn't allow. And, yeah, TB not GB. The DAT tapes I used previously were in the GB range as I vaguely recall.
    - pixl97 11y ago
      >Because tapes are much less fragile than hard disks, In 'single serve server' configurations, such as small businesses, tapes work well because administrative rather than technical staff can replace the tapes daily reducing costs. If the tape is ejected then the user knows it safe to put the next tape in. If there is a failure the software itself can notify a systems administrator. With hard drives a non technical user has no idea if the disk is still mounted and live, leading to corruption issues if it is removed.
      - hga 11y ago
        And even more fragile if still spinning ... yeah, it would never occur to me to have anyone but trusted technical staff physically swapping hard disks around. Whereas I think people, at least us older types who used VHS tapes especially, have an idea for how tough/fragile computer backup tapes are (maybe a little tougher than a VHS tape, but not enough to make a difference in how you handle it). (We'll ignore for the moment that I never trusted anyone but myself to run the backup system and mount and unmount tapes, with one exception. :-)
e40 11y ago
Yep. For Macs, that means something like TM + Superduper (or CCC). I do a weekly backup with SD which I copy to another machine on my network and backup offsite.

by cdumler 11y ago

dozzie 11y ago

There is this joke that you need three, in case your second one is damaged, because the first one will be damaged for sure. I heard it in form about lighters in survival.

hga 11y ago

I like to say that if you have 1 copy, you have none. If 2, 1, if 3, you have 2 copies, the absolute minimum. And try to decrease single points of failure, e.g. I use rsync for rsync.net and BackupPC to local disk, and tar to LTO tape after giving up on the opaque and baroque Bacula. You need one offsite to prevent your house burns down and takes your machines and local backups. I'm a long term fan of tape, from the first time I used UNIX(TM) in 1978 and a DECTape saved me when I was learning the power of the -rf flags to rm. LTO tape systems for the home are not insanely expensive (then again, this is my minimum system today: https://news.ycombinator.com/item?id=10483361 https://news.ycombinator.com/item?id=10483361 ECC is a requirement for me). Street price for the HP LTO-4 internal SAS EH919SB I'm currently using is ~1,300 USD (and it wasn't difficult to get it at around that price in 2011). Add a LSI 2004 chip based SAS-2 controller such as the "Avago" LSI 9211-4i at $167 from Newegg right now to drive it, and a semi-disposable flash drive to feed it quickly so the tape doesn't "shoe shine" (the tape moves very quickly, if you don't feed it quickly enough it has to stop the tape and backup enough so that it's at speed when it starts forward again and hits the location where it ran out). I.e. at whatever speed write a 10GiB slice of your backup to the flash drive, then write that all at once to the tape. Considering media costs, if you start from scratch today you'd probably be better off going LTO-5 now that LTO-6 is shipping, the media costs the same as for LTO-4 despite a near doubling of capacity. I've got enough LTO-4 tapes that I'll keep using them until my LTO-4 drive dies, then buy an LTO-5 drive, which per the standard can read two earlier generations, and write 1 earlier, and new LTO-5 media for it. Current LTO-4 and LTO-5 tapes from HP or Fuji (I wouldn't trust anyone else) go for $22-23, uncompressed capacities are 800 and 1.5 GB respectively. And then store copies off-site, and copy your most important stuff at least once a day to a site like rsync.net, which saved me when a tornado trashed my apartment in 2011.

bboreham 11y ago
> Current LTO-4 and LTO-5 tapes [...] go for $22-23, uncompressed capacities are 800 and 1.5 GB respectively. I think you meant 1.5TB. However, why not just use hard disk drives at just over twice that price? You'd get quite a lot of them for the cost of the tape drive.
- hga 11y ago
  Because tapes are much less fragile than hard disks, and I can stash a bunch of tapes in my safe deposit box and other places. As well as have many copies of my data as I keep monthly full backups for at least a year. And, hmmm, my tapes as I use them are more reliable than my Seagate enterprise disks, and that's with the latter not moving around (i.e. in all my post-mid-2011 tornado hardware, I've had two disk failures and no tape failures). For the level of data security I want, and the tiny AT&T DSL straw I'm currently forced to use, even with things like Amazon Snowball and ever lower prices on "nearline" cloud storage, if a tape drive lasts long enough, the numbers work better for tape. And compared to the usual enterprise, I don't beat up on tape drives, they're over-engineered for my duty cycle. I also have a desire to be able to make due without monthly charges, which a cloud solution doesn't allow. And, yeah, TB not GB. The DAT tapes I used previously were in the GB range as I vaguely recall.
  - pixl97 11y ago
    >Because tapes are much less fragile than hard disks, In 'single serve server' configurations, such as small businesses, tapes work well because administrative rather than technical staff can replace the tapes daily reducing costs. If the tape is ejected then the user knows it safe to put the next tape in. If there is a failure the software itself can notify a systems administrator. With hard drives a non technical user has no idea if the disk is still mounted and live, leading to corruption issues if it is removed.
    - hga 11y ago
      And even more fragile if still spinning ... yeah, it would never occur to me to have anyone but trusted technical staff physically swapping hard disks around. Whereas I think people, at least us older types who used VHS tapes especially, have an idea for how tough/fragile computer backup tapes are (maybe a little tougher than a VHS tape, but not enough to make a difference in how you handle it). (We'll ignore for the moment that I never trusted anyone but myself to run the backup system and mount and unmount tapes, with one exception. :-)

e40 11y ago

Yep. For Macs, that means something like TM + Superduper (or CCC). I do a weekly backup with SD which I copy to another machine on my network and backup offsite.