1. 24 Jan, 2013 1 commit
    • Jonathan Brassow's avatar
      DM-RAID: Fix RAID10's check for sufficient redundancy · 55ebbb59
      Jonathan Brassow authored
      Before attempting to activate a RAID array, it is checked for sufficient
      redundancy.  That is, we make sure that there are not too many failed
      devices - or devices specified for rebuild - to undermine our ability to
      activate the array.  The current code performs this check twice - once to
      ensure there were not too many devices specified for rebuild by the user
      ('validate_rebuild_devices') and again after possibly experiencing a failure
      to read the superblock ('analyse_superblocks').  Neither of these checks are
      sufficient.  The first check is done properly but with insufficient
      information about the possible failure state of the devices to make a good
      determination if the array can be activated.  The second check is simply
      done wrong in the case of RAID10 because it doesn't account for the
      independence of the stripes (i.e. mirror sets).  The solution is to use the
      properly written check ('validate_rebuild_devices'), but perform the check
      after the superblocks have been read and we know which devices have failed.
      This gives us one check instead of two and performs it in a location where
      it can be done right.
      Only RAID10 was affected and it was affected in the following ways:
      - the code did not properly catch the condition where a user specified
        a device for rebuild that already had a failed device in the same mirror
        set.  (This condition would, however, be caught at a deeper level in MD.)
      - the code triggers a false positive and denies activation when devices in
        independent mirror sets have failed - counting the failures as though they
        were all in the same set.
      The most likely place this error was introduced (or this patch should have
      been included) is in commit 4ec1e369
       - first introduced in v3.7-rc1.
      Consequently this fix should also go in v3.7.y, however there is a
      small conflict on the .version in raid_target, so I'll submit a
      separate patch to -stable.
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarJonathan Brassow <jbrassow@redhat.com>
      Signed-off-by: default avatarNeilBrown <neilb@suse.de>
  2. 11 Oct, 2012 1 commit
  3. 01 Aug, 2012 1 commit
  4. 27 Jul, 2012 3 commits
  5. 03 Jul, 2012 1 commit
  6. 02 Jun, 2012 1 commit
    • Joe Thornber's avatar
      dm thin: provide userspace access to pool metadata · cc8394d8
      Joe Thornber authored
      This patch implements two new messages that can be sent to the thin
      pool target allowing it to take a snapshot of the _metadata_.  This,
      read-only snapshot can be accessed by userland, concurrently with the
      live target.
      Only one metadata snapshot can be held at a time.  The pool's status
      line will give the block location for the current msnap.
      Since version 0.1.5 of the userland thin provisioning tools, the
      thin_dump program displays the msnap as follows:
          thin_dump -m <msnap root> <metadata dev>
      Available here: https://github.com/jthornber/thin-provisioning-tools
      Now that userland can access the metadata we can do various things
      that have traditionally been kernel side tasks:
           i) Incremental backups.
           By using metadata snapshots we can work out what blocks have
           changed over time.  Combined with data snapshots we can ensure
           the data doesn't change while we back it up.
           A short proof of concept script can be found here:
           ii) Migration of thin devices from one pool to another.
           iii) Merging snapshots back into an external origin.
           iv) Asyncronous replication.
      Signed-off-by: default avatarJoe Thornber <ejt@redhat.com>
      Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
  7. 28 Mar, 2012 5 commits
  8. 07 Mar, 2012 1 commit
  9. 21 Feb, 2012 1 commit
  10. 31 Oct, 2011 3 commits
    • Jonathan Brassow's avatar
      dm log userspace: fix comment hyphens · b8954457
      Jonathan Brassow authored
      Fix comments: clustered-disk needs a hyphen not an underscore.
      Signed-off-by: default avatarJonathan Brassow <jbrassow@redhat.com>
      Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
    • Joe Thornber's avatar
      dm: add thin provisioning target · 991d9fa0
      Joe Thornber authored
      Initial EXPERIMENTAL implementation of device-mapper thin provisioning
      with snapshot support.  The 'thin' target is used to create instances of
      the virtual devices that are hosted in the 'thin-pool' target.  The
      thin-pool target provides data sharing among devices.  This sharing is
      made possible using the persistent-data library in the previous patch.
      The main highlight of this implementation, compared to the previous
      implementation of snapshots, is that it allows many virtual devices to
      be stored on the same data volume, simplifying administration and
      allowing sharing of data between volumes (thus reducing disk usage).
      Another big feature is support for arbitrary depth of recursive
      snapshots (snapshots of snapshots of snapshots ...).  The previous
      implementation of snapshots did this by chaining together lookup tables,
      and so performance was O(depth).  This new implementation uses a single
      data structure so we don't get this degradation with depth.
      For further information and examples of how to use this, please read
      Signed-off-by: default avatarJoe Thornber <thornber@redhat.com>
      Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
      Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
    • Joe Thornber's avatar
      dm: add persistent data library · 3241b1d3
      Joe Thornber authored
      The persistent-data library offers a re-usable framework for the storage
      and management of on-disk metadata in device-mapper targets.
      It's used by the thin-provisioning target in the next patch and in an
      upcoming hierarchical storage target.
      For further information, please read
      Signed-off-by: default avatarJoe Thornber <thornber@redhat.com>
      Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
      Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
  11. 02 Aug, 2011 7 commits
  12. 31 Mar, 2011 1 commit
  13. 24 Mar, 2011 1 commit
  14. 13 Jan, 2011 3 commits
    • Andrea Gelmini's avatar
    • NeilBrown's avatar
      dm: raid456 basic support · 9d09e663
      NeilBrown authored
      This patch is the skeleton for the DM target that will be
      the bridge from DM to MD (initially RAID456 and later RAID1).  It
      provides a way to use device-mapper interfaces to the MD RAID456
      As with all device-mapper targets, the nominal public interfaces are the
      constructor (CTR) tables and the status outputs (both STATUSTYPE_INFO
      and STATUSTYPE_TABLE).  The CTR table looks like the following:
      1: <s> <l> raid \
      2:	<raid_type> <#raid_params> <raid_params> \
      3:	<#raid_devs> <meta_dev1> <dev1> .. <meta_devN> <devN>
      Line 1 contains the standard first three arguments to any device-mapper
      target - the start, length, and target type fields.  The target type in
      this case is "raid".
      Line 2 contains the arguments that define the particular raid
      type/personality/level, the required arguments for that raid type, and
      any optional arguments.  Possible raid types include: raid4, raid5_la,
      raid5_ls, raid5_rs, raid6_zr, raid6_nr, and raid6_nc.  (again, raid1 is
      planned for the future.)  The list of required and optional parameters
      is the same for all the current raid types.  The required parameters are
      positional, while the optional parameters are given as key/value pairs.
      The possible parameters are as follows:
       <chunk_size>		Chunk size in sectors.
       [[no]sync]		Force/Prevent RAID initialization
       [rebuild <idx>]	Rebuild the drive indicated by the index
       [daemon_sleep <ms>]	Time between bitmap daemon work to clear bits
       [min_recovery_rate <kB/sec/disk>]	Throttle RAID initialization
       [max_recovery_rate <kB/sec/disk>]	Throttle RAID initialization
       [max_write_behind <value>]		See '-write-behind=' (man mdadm)
       [stripe_cache <sectors>]		Stripe cache size for higher RAIDs
      Line 3 contains the list of devices that compose the array in
      metadata/data device pairs.  If the metadata is stored separately, a '-'
      is given for the metadata device position.  If a drive has failed or is
      missing at creation time, a '-' can be given for both the metadata and
      data drives for a given position.
      # RAID4 - 4 data drives, 1 parity
      # No metadata devices specified to hold superblock/bitmap info
      # Chunk size of 1MiB
      # (Lines separated for easy reading)
      0 1960893648 raid \
      	raid4 1 2048 \
      	5 - 8:17 - 8:33 - 8:49 - 8:65 - 8:81
      # RAID4 - 4 data drives, 1 parity (no metadata devices)
      # Chunk size of 1MiB, force RAID initialization,
      #	min recovery rate at 20 kiB/sec/disk
      0 1960893648 raid \
              raid4 4 2048 min_recovery_rate 20 sync\
              5 - 8:17 - 8:33 - 8:49 - 8:65 - 8:81
      Performing a 'dmsetup table' should display the CTR table used to
      construct the mapping (with possible reordering of optional
      Performing a 'dmsetup status' will yield information on the state and
      health of the array.  The output is as follows:
      1: <s> <l> raid \
      2:	<raid_type> <#devices> <1 health char for each dev> <resync_ratio>
      Line 1 is standard DM output.  Line 2 is best shown by example:
      	0 1960893648 raid raid4 5 AAAAA 2/490221568
      Here we can see the RAID type is raid4, there are 5 devices - all of
      which are 'A'live, and the array is 2/490221568 complete with recovery.
      Cc: linux-raid@vger.kernel.org
      Signed-off-by: default avatarNeilBrown <neilb@suse.de>
      Signed-off-by: default avatarJonathan Brassow <jbrassow@redhat.com>
      Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
      Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
    • Milan Broz's avatar
      dm crypt: add multi key capability · d1f96423
      Milan Broz authored
      This patch adds generic multikey handling to be used
      in following patch for Loop-AES mode compatibility.
      This patch extends mapping table to optional keycount and
      implements generic multi-key capability.
      With more keys defined the <key> string is divided into
      several <keycount> sections and these are used for tfms.
      The tfm is used according to sector offset
      (sector 0->tfm[0], sector 1->tfm[1], sector N->tfm[N modulo keycount])
      (only power of two values supported for keycount here).
      Because of tfms per-cpu allocation, this mode can be take
      a lot of memory on large smp systems.
      Signed-off-by: default avatarMilan Broz <mbroz@redhat.com>
      Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
      Cc: Max Vozeler <max@hinterhof.net>
  15. 04 Aug, 2010 1 commit
    • Justin P. Mattock's avatar
      Documentation: update broken web addresses. · 0ea6e611
      Justin P. Mattock authored
      Below you will find an updated version from the original series bunching all patches into one big patch
      updating broken web addresses that are located in Documentation/*
      Some of the addresses date as far far back as 1995 etc... so searching became a bit difficult,
      the best way to deal with these is to use web.archive.org to locate these addresses that are outdated.
      Now there are also some addresses pointing to .spec files some are located, but some(after searching
      on the companies site)where still no where to be found. In this case I just changed the address
      to the company site this way the users can contact the company and they can locate them for the users.
      Signed-off-by: default avatarJustin P. Mattock <justinmattock@gmail.com>
      Signed-off-by: default avatarThomas Weber <weber@corscience.de>
      Signed-off-by: default avatarMike Frysinger <vapier.adi@gmail.com>
      Cc: Paulo Marques <pmarques@grupopie.com>
      Cc: Randy Dunlap <rdunlap@xenotime.net>
      Cc: Michael Neuling <mikey@neuling.org>
      Signed-off-by: Jiri Kos...
  16. 06 Mar, 2010 1 commit
  17. 10 Dec, 2009 1 commit
  18. 22 Jun, 2009 3 commits
  19. 25 Apr, 2008 1 commit
  20. 20 Oct, 2007 1 commit
  21. 09 May, 2007 1 commit
  22. 07 Nov, 2005 1 commit