Forum Discussion

tanislavm's avatar
tanislavm
Level 6
11 years ago

vxvm

Hi,

I wish to verify things.

Any application is aware only of the file system and not aware of what logical volume is underneath.right?So if one logical volume (from an mirror logical volume) fails,the application still continue to work on this file system.The application open i-node then work with them,and those things are in superblock,means in file system.

 

 

The maximum size of the logical volume i can create is limited by the maximum size the file system could support.Right?

 

The advantages of having vxvm over having only disk partitions are:

- migration online of the logical volume

-take snapshot and then online backup

-convert from linear vxvm to raid and vice versa 

-extend,shrink online

 

All the time is an trade off having vxvm as an intermediate layer over not having this layer but only simple disk partitions.

 

 

 

thanks.

 

business continuity
Solaris
Storage Foundation
  • TonyGriffiths's avatar
    TonyGriffiths
    11 years ago

    Hi,

    This post would be better served in the Storage Foundation forum.

    To answer some of your Qs:

    1) If an Application uses a file system, then yes the app will only be aware of the file system and not the device layer that storage the file system. If a file system is being used on a redundant (RAID1, RAID5 etc) logical volume and a disk fails, the volume will still be accessible and the file system i/o will continue

    2) The max logical volume size is usually bound by disk size & disk partition layout and OS. The max size of a volume is not bound by the FS, but the FS may have its own limits.

    3) Advantages of VxVM over disk partitioning, here are some for a start (others can fill in any gaps)

    Ability to span data over multiple disks, RAID 0,1,5, Online resize (grow&shrink), online volume layout, Online data migration, Diskgroup portability, Snapshots, DiskGroup/split-join, Sharing of volumes to multiple hosts (CVM), Storage Tiering (SF), Dynamic Multi-pathing (Perfromance&Availability), Cloned disk support, Deduplication (SF), Compression (SF), Data replication (VVR), Centralised Storage management (VOM), Flash Cache, Thin Reclamation (SF), Hot relocation, Site awareness

     

    cheers

    tony

  • TonyGriffiths's avatar
    TonyGriffiths
    Level 6
    11 years ago

    Hi,

    This post would be better served in the Storage Foundation forum.

    To answer some of your Qs:

    1) If an Application uses a file system, then yes the app will only be aware of the file system and not the device layer that storage the file system. If a file system is being used on a redundant (RAID1, RAID5 etc) logical volume and a disk fails, the volume will still be accessible and the file system i/o will continue

    2) The max logical volume size is usually bound by disk size & disk partition layout and OS. The max size of a volume is not bound by the FS, but the FS may have its own limits.

    3) Advantages of VxVM over disk partitioning, here are some for a start (others can fill in any gaps)

    Ability to span data over multiple disks, RAID 0,1,5, Online resize (grow&shrink), online volume layout, Online data migration, Diskgroup portability, Snapshots, DiskGroup/split-join, Sharing of volumes to multiple hosts (CVM), Storage Tiering (SF), Dynamic Multi-pathing (Perfromance&Availability), Cloned disk support, Deduplication (SF), Compression (SF), Data replication (VVR), Centralised Storage management (VOM), Flash Cache, Thin Reclamation (SF), Hot relocation, Site awareness

     

    cheers

    tony