Backup & Restore - Redhat

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  1. Backup & Restore

    What is the most common way to backup a Linux server? Is true that the
    dump utility is not recommended on Linux? Is there any way to create
    some kind of “full system backup”? I mean a backup that not only
    backup my data but also the Linux packages installed in such a way
    that I can restore the “complete” system without reinstalling the OS
    and applications first? Will this full system backup be capable of
    backing up database systems like mysql?

  2. Re: Backup & Restore

    On 08/29/2008 10:37 PM, Artificer sent:
    > What is the most common way to backup a Linux server? Is true that the
    > dump utility is not recommended on Linux? Is there any way to create
    > some kind of “full system backup”? I mean a backup that not only
    > backup my data but also the Linux packages installed in such a way
    > that I can restore the “complete” system without reinstalling the OS
    > and applications first? Will this full system backup be capable of
    > backing up database systems like mysql?


    Hello Artificer:

    I think within a few hours, you're going to get differing opinions from
    many. Perhaps what best describes your request, is information having
    to do with "Bare Metal Recovery". Total solutions might include those
    that are based on "dd" and anything that reads and writes at the sector
    level. Of course sector level reads/writes don't know or care what
    MySQL, the OS, or data and applications are.

    Does your server situation allow downtime such that a total image can be
    taken of an operation _not_ handling transactions? Is your server based
    on a RAID storage system? If not, is it viable to start looking at one?
    Have you looked into "Ghost4Linux"? What media would you be storing
    your backups to? Are you familiar with rsync based backups? Would you
    be able to look into commercial solutions? Try Googling for "Bare Metal
    Recovery" and afterwards maybe your questions will have expanded.

    Best wishes to you.

    --
    1PW

    @?6A62?FEH9E=6o2@=]4@> [r4o7t]

  3. Re: Backup & Restore

    1PW wrote:
    > On 08/29/2008 10:37 PM, Artificer sent:
    >> What is the most common way to backup a Linux server? Is true that the
    >> dump utility is not recommended on Linux? Is there any way to create
    >> some kind of “full system backup”? I mean a backup that not only
    >> backup my data but also the Linux packages installed in such a way
    >> that I can restore the “complete” system without reinstalling the OS
    >> and applications first? Will this full system backup be capable of
    >> backing up database systems like mysql?

    >
    > Hello Artificer:
    >
    > I think within a few hours, you're going to get differing opinions from
    > many. Perhaps what best describes your request, is information having
    > to do with "Bare Metal Recovery". Total solutions might include those
    > that are based on "dd" and anything that reads and writes at the sector
    > level. Of course sector level reads/writes don't know or care what
    > MySQL, the OS, or data and applications are.
    >
    > Does your server situation allow downtime such that a total image can be
    > taken of an operation _not_ handling transactions? Is your server based
    > on a RAID storage system? If not, is it viable to start looking at one?
    > Have you looked into "Ghost4Linux"? What media would you be storing
    > your backups to? Are you familiar with rsync based backups? Would you
    > be able to look into commercial solutions? Try Googling for "Bare Metal
    > Recovery" and afterwards maybe your questions will have expanded.
    >
    > Best wishes to you.


    All that's good, but not enough information for him. 'dump' and 'dd' talk
    directly to the disk: because Linux hasn't necessarily transferred data to the
    disk, but may still have it paged out in RAM, this can present a corrupted
    filesystem or database if the timing of the dump is even a little bit off with
    database operations or filesystem changes. So 'dump' and 'dd' are only good
    for locked turn, turned-off copies of Linux.

    Amanda is one of the most popular tools: it's built into every major Linux
    distribution, it's flexible, it's powerful, and it's simple in the tools it
    uses. And you can *ALWAYS* read the tapes later, because it's using GNU-tar as
    it's basic tape-writing tool. It's good freeware, and if you want commercial
    support and accountability for it, you can contact zmanda.com for it.

  4. Re: Backup & Restore

    On Aug 30, 7:00*am, Nico Kadel-Garcia wrote:
    > 1PW wrote:
    > > On 08/29/2008 10:37 PM, Artificer sent:
    > >> What is the most common way to backup a Linux server? Is true that the
    > >> dump utility is not recommended on Linux? Is there any way to create
    > >> some kind of “full system backup”? I mean a backup that not only
    > >> backup my data but also the Linux packages installed in such a way
    > >> that I can restore the “complete” system without reinstalling the OS
    > >> and applications first? Will this full system backup be capable of
    > >> backing up database systems like mysql?

    >
    > > Hello Artificer:

    >
    > > I think within a few hours, you're going to get differing opinions from
    > > many. *Perhaps what best describes your request, is information having
    > > to do with "Bare Metal Recovery". *Total solutions might include those
    > > that are based on "dd" and anything that reads and writes at the sector
    > > level. *Of course sector level reads/writes don't know or care what
    > > MySQL, the OS, or data and applications are.

    >
    > > Does your server situation allow downtime such that a total image can be
    > > taken of an operation _not_ handling transactions? *Is your server based
    > > on a RAID storage system? *If not, is it viable to start looking at one?
    > > Have you looked into "Ghost4Linux"? *What media would you be storing
    > > your backups to? *Are you familiar with rsync based backups? *Wouldyou
    > > be able to look into commercial solutions? *Try Googling for "Bare Metal
    > > Recovery" and afterwards maybe your questions will have expanded.

    >
    > > Best wishes to you.

    >
    > All that's good, but not enough information for him. 'dump' and 'dd' talk
    > directly to the disk: because Linux hasn't necessarily transferred data to the
    > disk, but may still have it paged out in RAM, this can present a corrupted
    > filesystem or database if the timing of the dump is even a little bit offwith
    > database operations or filesystem changes. So 'dump' and 'dd' are only good
    > for locked turn, turned-off copies of Linux.
    >
    > Amanda is one of the most popular tools: it's built into every major Linux
    > distribution, it's flexible, it's powerful, and it's simple in the tools it
    > uses. And you can *ALWAYS* read the tapes later, because it's using GNU-tar as
    > it's basic tape-writing tool. It's good freeware, and if you want commercial
    > support and accountability for it, you can contact zmanda.com for it.- Hide quoted text -
    >
    > - Show quoted text -


    Won't Amanda gonna have the same limitations as 'dump' and 'dd'?

  5. Re: Backup & Restore

    On Aug 30, 3:25*am, 1PW wrote:
    > On 08/29/2008 10:37 PM, Artificer sent:
    >
    > > What is the most common way to backup a Linux server? Is true that the
    > > dump utility is not recommended on Linux? Is there any way to create
    > > some kind of “full system backup”? I mean a backup that not only
    > > backup my data but also the Linux packages installed in such a way
    > > that I can restore the “complete” system without reinstalling the OS
    > > and applications first? Will this full system backup be capable of
    > > backing up database systems like mysql?

    >
    > Hello Artificer:
    >
    > I think within a few hours, you're going to get differing opinions from
    > many. *Perhaps what best describes your request, is information having
    > to do with "Bare Metal Recovery". *Total solutions might include those
    > that are based on "dd" and anything that reads and writes at the sector
    > level. *Of course sector level reads/writes don't know or care what
    > MySQL, the OS, or data and applications are.
    >
    > Does your server situation allow downtime such that a total image can be
    > taken of an operation _not_ handling transactions? *Is your server based
    > on a RAID storage system? *If not, is it viable to start looking at one?
    > Have you looked into "Ghost4Linux"? *What media would you be storing
    > your backups to? *Are you familiar with rsync based backups? *Would you
    > be able to look into commercial solutions? *Try Googling for "Bare Metal
    > Recovery" and afterwards maybe your questions will have expanded.
    >
    > Best wishes to you.
    >
    > --
    > 1PW
    >
    > @?6A62?FEH9E=6o2@=]4@> [r4o7t]


    At this point I would prefer an open source solution! In order to
    clone a disk using dd do I have to somekind of 'rescue disk'? will dd
    be able to clone a windows NTFS disk?

  6. Re: Backup & Restore

    Artificer wrote:
    > On Aug 30, 7:00 am, Nico Kadel-Garcia wrote:
    >> 1PW wrote:


    >> Amanda is one of the most popular tools: it's built into every major Linux
    >> distribution, it's flexible, it's powerful, and it's simple in the tools it
    >> uses. And you can *ALWAYS* read the tapes later, because it's using GNU-tar as
    >> it's basic tape-writing tool. It's good freeware, and if you want commercial
    >> support and accountability for it, you can contact zmanda.com for it.-


    >
    > Won't Amanda gonna have the same limitations as 'dump' and 'dd'?


    Nope. See above: Amanda mostly uses GNU-tar, which talks to the file system
    seen by the user, not to the raw disk. You still have the issue of getting
    accurate dumps of databases, which needs to be an 'atomic' operation. But
    that's what user-land tools that dump databases or snapshot them are for.

  7. Re: Backup & Restore

    On 2008-08-30, Artificer wrote:

    > What is the most common way to backup a Linux server? Is true that the
    > dump utility is not recommended on Linux?


    The problem with dump on linux is that unlike, say FreeBSD, linux' dump
    does not have a built-in means of making a filesystem snapshot to backup
    a live filesystem. If you're using lvm on linux you can accomplish the
    same thing as FreeBSD dump's "-L" switch by using "lvcreate" to make a
    snapshot volume for dump to use, and "lvremove" to clear it after the
    dump is complete.

    --

    John (john@os2.dhs.org)
    ** Posted from http://www.teranews.com **

  8. Re: Backup & Restore

    John Thompson wrote:
    > On 2008-08-30, Artificer wrote:
    >
    >> What is the most common way to backup a Linux server? Is true that the
    >> dump utility is not recommended on Linux?

    >
    > The problem with dump on linux is that unlike, say FreeBSD, linux' dump
    > does not have a built-in means of making a filesystem snapshot to backup
    > a live filesystem. If you're using lvm on linux you can accomplish the
    > same thing as FreeBSD dump's "-L" switch by using "lvcreate" to make a
    > snapshot volume for dump to use, and "lvremove" to clear it after the
    > dump is complete.
    >


    No, you can't. Linux does a great deal of paging: it will page to the extent
    of available RAM. Writing such data to disk *cannot* be relied on, unless you
    do something like locking the databases and running 'sync' to force changes to
    be written to disk. This flaw of the 'dump' command is old, and there is no
    complete solution for most file-based tools.

  9. Re: Backup & Restore

    On Aug 31, 3:13*pm, Nico Kadel-Garcia wrote:
    > John Thompson wrote:
    > > On 2008-08-30, Artificer wrote:

    >
    > >> What is the most common way to backup a Linux server? Is true that the
    > >> dump utility is not recommended on Linux?

    >
    > > The problem with dump on linux is that unlike, say FreeBSD, linux' dump
    > > does not have a built-in means of making a filesystem snapshot to backup
    > > a live filesystem. If you're using lvm on linux you can accomplish the
    > > same thing as FreeBSD dump's "-L" switch by using "lvcreate" to make a
    > > snapshot volume for dump to use, and "lvremove" to clear it after the
    > > dump is complete.

    >
    > No, you can't. Linux does a great deal of paging: it will page to the extent
    > of available RAM. Writing such data to disk *cannot* be relied on, unlessyou
    > do something like locking the databases and running 'sync' to force changes to
    > be written to disk. This flaw of the 'dump' command is old, and there is no
    > complete solution for most file-based tools.


    So basically what your saying is that the best backup tool for linux
    is gnu tar + the tools provided on DBRMS? Can I do a something similar
    like a "bare metal" restore by installing a new copy of the linux
    distro that I am using and after that booting the new computer with a
    rescue disk and untar my full disk backup on top of it? Of course
    database restore will be done after the untar and reboot!

    Did I undestand wrong or your trying to say that GNU tar will "see"
    the filesystem not as it is on disk but as it should be seen from a
    user perspective?

  10. Re: Backup & Restore

    I use dump and restore to do whole sale backups of any particular
    ext2/ext3 partition. They are easy to use, preserve ALL files and work
    quickly. Restores interactive mode is useful for picking select files
    to restore.

    The only catch is, you can't/shouldn't run dump on a live filesystem.
    It should be unmounted when you dump it OR mounted read only. Using
    dump is only an issue if you have to backup a filesystem while mounted
    read/write. Dump is perfectly good for unmounted/read only filesystems.

    For instance, to backup my root partition, I issue this commant first

    mount / -o ro,remount

    Then run dump then

    mount / -o rw,remount

    The real advantage is that its FAST and comprehensive.
    Artificer wrote:
    > What is the most common way to backup a Linux server? Is true that the
    > dump utility is not recommended on Linux? Is there any way to create
    > some kind of “full system backup”? I mean a backup that not only
    > backup my data but also the Linux packages installed in such a way
    > that I can restore the “complete” system without reinstalling the OS
    > and applications first? Will this full system backup be capable of
    > backing up database systems like mysql?


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