Kevin Laurie
2015-Aug-09 16:33 UTC
backing up email / saving maildir on external hard drives
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 <slitt at troubleshooters.com> wrote:> On Sat, 8 Aug 2015 10:26:55 +0530 > Kevin Laurie <superinterstellar at 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 at mydesq2:~$ df -h ~/mail/Maildir > Filesystem Size Used Avail Use% Mounted on > /dev/sdb8 116G 11G 100G 10% /home/slitt/mail/Maildir > slitt at 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 >
Götz Reinicke - IT Koordinator
2015-Aug-11 13:45 UTC
backing up email / saving maildir on external hard drives
Hi, talking of rsync and compression is may be also a bit misleading. On the destination there will be no compressed files if you transfer with rsync! The transfere on the network by rsync might be compressed! /G?tz Am 09.08.15 um 18:33 schrieb Kevin Laurie:> 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 <slitt at troubleshooters.com> wrote: > >> On Sat, 8 Aug 2015 10:26:55 +0530 >> Kevin Laurie <superinterstellar at 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 at mydesq2:~$ df -h ~/mail/Maildir >> Filesystem Size Used Avail Use% Mounted on >> /dev/sdb8 116G 11G 100G 10% /home/slitt/mail/Maildir >> slitt at 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 >>-- G?tz Reinicke IT-Koordinator Tel. +49 7141 969 82420 E-Mail goetz.reinicke at filmakademie.de Filmakademie Baden-W?rttemberg GmbH Akademiehof 10 71638 Ludwigsburg www.filmakademie.de Eintragung Amtsgericht Stuttgart HRB 205016 Vorsitzender des Aufsichtsrats: J?rgen Walter MdL Staatssekret?r im Ministerium f?r Wissenschaft, Forschung und Kunst Baden-W?rttemberg Gesch?ftsf?hrer: Prof. Thomas Schadt -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/pkcs7-signature Size: 5481 bytes Desc: S/MIME Cryptographic Signature URL: <http://dovecot.org/pipermail/dovecot/attachments/20150811/d9a59f29/attachment-0001.p7s>
Christian Schmidt
2015-Aug-11 15:56 UTC
backing up email / saving maildir on external hard drives
On 11.08.2015 15:45, G?tz Reinicke - IT Koordinator wrote:> talking of rsync and compression is may be also a bit misleading. > > On the destination there will be no compressed files if you transfer > with rsync!...unless your dovecot is working with compressed maildir files. ;-) Kind Regards, Christian Schmidt -- No signature available. -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/pkcs7-signature Size: 5306 bytes Desc: S/MIME Cryptographic Signature URL: <http://dovecot.org/pipermail/dovecot/attachments/20150811/08459bbb/attachment.p7s>
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