[linux] online backup

[Martin Mosny]

Hello Peter,

Thursday, June 13, 2002, 2:53:07 PM, you wrote:

PR> On Thu, 2002-06-13 at 10:58, Martin Mosny wrote:
>> Ahojte,
>> 
>> pozeral som si archiv mailing listu, ale takyto $SUBJ som nenasiel.
>> 
>> preto  by  som sa chcel opytat, ci ma niekto skusenosti so zalohovanim
>> systemu,  ktory  nie  je  mozne vypnut, umountnut (24/7/365).
>> 
>> ako jedno z moznych rieseni sa rysuje LVM alebo nejaky raid (1-5).
>> 
>> ale  ma  niekto  nejaky  iny napad? podstata je ziskat nejaky zmrazeny
>> obraz systemu na dobu zalohovania.
>> 
>> ak   ma   niekto   skusenosti  s  LVM  pls.  ozvite  sa,  skusal  som
>> HOWTO-LVM-SnapShot  ale  asi  nedostatocne  citam medzi riadkami, lebo
>> podla ich navodu to nejde :(
>> 
>> za akykolvek napad budem vdacny!

PR> hovori sa tomu hotbackup
PR> coldbackup je ked system musi koli tomu zastat
PR> co teda ja viem tak sa to da aj s amandou ktora je free
PR> co to ma ale spolocne s raid a lvm, to neviem :(

Neviem  ci  to  ide,  alebo nie, lebo to nemam odskusane, ani nepoznam
nikoho  kto  by to mal, ale ako pisu na ich stranke: " ... AMANDA runs
the   client dump program.  This  is currently  hardcoded for a vendor
dump  program, GNU tar  or  SAMBA  tar.  The new  mechanism will allow
arbitrary  programs  such   as  cpio, star, and possibly  other backup
systems.  It will also add  optional  pre-dump  and  post-dump   steps
that    can  be  used  for  locking  and  unlocking,  and snapshots of
rapidly  changing data such as databases."

podstatne  su  tam  slova "currently hardcoded dump" a "new  mechanism
will allow ..." a "It will also add... pre and post dump".

a co to ma spolocne s LVM alebo RAID, no to ze LVM vie urobit snapshot
particie,  ktora sa da BEZBOLESTNE odzalohovat. A raid no aspon to, ze
pri  pouziti  dvoch  diskov,  ak  jeden  odide,  stale z druheho mozem
fungovat!

PR> raid by mal sluzit na zvysenie dostupnosti skrz vacsej dostupnosti
PR> storage, nie je ale primarne urceny na zalohy

no mas pravdy, ale na co potom vymysleli RAID-1

RAID-1
RAID  Level  1  provides redundancy by writing all data to two or more
drives.   The  performance  of  a  level 1 array tends to be faster on
reads  and slower  on writes compared to a single drive, but if either
drive  fails,  no  data  is lost.
This  is  a  good entry-level redundant system, This level is commonly
referred to as mirroring.

PR> lvm je to iste v softverovej podobe (zatiahne to procak)
PR> tiez lvm sa vytvara az po instalacii os kdezto na riad uz instalujeme
PR> dz

to my je jasne!

ide  mi  o  to  zalohovat  system,  ktory sa meni kazdu sekundu a dost
rapidnym sposobom.

-- 
   m0s