Dear Steve, Very valuable info. Appreciate it and will be careful when using terms. Actually I think I should just use rsync without compressing. The reason why I started compressing was because the GUI gave some errors when I was trying to copy then files.
I'll just rsync the data from my laptop HDD to my external drive(without compressing) Thanks Kevin On Sunday, August 9, 2015, Steve Litt <sl...@troubleshooters.com> wrote: > On Sat, 8 Aug 2015 10:26:55 +0530 > Kevin Laurie <superinterstel...@gmail.com <javascript:;>> wrote: > > > Hello, > > Yesterday I tried to back up a 40GB maildir . > > I tried to move the maildir from home to external HDD but failed. > > If you tried to *move* it it's an archive, not a backup. If you tried > to *copy* it, with the intent of keeping the original on the original > hard disk and using it further, and keeping today's copy on some other > media, *that's* a backup. I'm not trying to be pedantic, but there are > many distinctions between the two. Archives must be re-transferred > frequently: Backups merely need to be redone at intervals. > > > Decided then to compress it(which took several hours). Now changing > > the disk format from FAT to exFAT to allow the transfer for the large > > compressed file. > > Reading https://en.wikipedia.org/wiki/File_Allocation_Table#exFAT , I > personally wouldn't use exFAT. Regular FAT32 has a max filesize of > 2GB-1, which is 50 times the size of your whole uncompressed maildir. > > > > > How does one back up emails on a external drive? > > Some advice would be greatly appreciated. > > Check this out: > > ================================================ > slitt@mydesq2:~$ df -h ~/mail/Maildir > Filesystem Size Used Avail Use% Mounted on > /dev/sdb8 116G 11G 100G 10% /home/slitt/mail/Maildir > slitt@mydesq2:~$ > ================================================ > > I don't have 40 GB, but * have 11, which is less than an order of > magnitude away. I just back up this puppy to my backup server with my > normal rsync based backup procedures, which you can read about here: > > * http://www.troubleshooters.com/lpm/200609/200609.htm > > * http://www.troubleshooters.com/linux/blu-ray-backup.htm > > * http://www.troubleshooters.com/lpm/201408/201408.htm > > The stuff about Blu-Ray is important only if you back up to blu-ray. I > like to keep some backups on write-once media, because kept in the > shade at reasonable temperatures and humidities, it tends to last > longer. And spinning disks that spend the majority of their time not > spinning tend to have problems. > > If this is a *backup*, I'd leave it uncompressed so you can take > incremental backups regularly. If it's an *archive*, meaning that the > data is immediately removed from your computer after copy, compression > might be in order, but you should make two copies and test them both > thoroughly before deleting the original, and you should test them every > couple months and if either goes bad, copy the other one to something > good. Archives are a PITA. For 40GB in these days of $150 2TB drives, > I'd keep the data intact, back it up, and when you outgrow your hard > drive, just get a bigger one. > > In other parts of this thread you ask how to separate backups from > different accounts from different computers. As far as accounts, I > think that Maildir directory structures would take care of that. As far > as different machines, just put the hostname at the front of each > destination directory. > > > > SteveT > > Steve Litt > July 2015 featured book: Rapid Learning for the 21st Century > http://www.troubleshooters.com/rl21 >