hcp

{page-title}{excerpt}{*}Hot Copy creates point-in-time snapshots of any Linux block device{*}{excerpt}

hcp \[--mount-point\] \[--skip-mount\] \[--read-only\] \[-c DEVICE\] \[-q QUOTA\] \[DEVICE\]

hcp \-l

hcp \-r \[DEVICE\]

hcp \-s \[DEVICE\]

h3. DESCRIPTION

Hot Copy creates a consistent point-in-time snapshot of a Linux block device.  Hot Copy does not use LVM.  Hot Copy snapshots are readable and writable.  Hot Copy by default uses the free space on the real block device to store changed blocks.  

h3. COPY-ON-WRITE CHANGED BLOCKS STORAGE

A copy-on-write method is used so Hot Copy uses no space until your real block device is changed.  As writes are made to the real block device Hot Copy makes a block-level backup copy of blocks before they are overwritten.  The changed blocks are stored in the Hot Copy changed block storage device.  This can be specified with the *(-c)* option.  By default changed blocks are stored on the same block device you are taking a Hot Copy of.  To prevent the Hot Copy changed blocks from potentially filling up your storage device with changed blocks during the copy-on-write used to maintain the snapshot hcp uses a free space quota.   If the percentage of free space on your changed blocks storage device is less than or equal to this percentage (default is 5%) then the Hot Copy will stop working.

h3. WRITABLE HOT COPIES

*\-m, \--mount-point* specify mount point of Hot Copy (default is /var/hotcopy/device)

*\--skip-mount* do not mount the Hot Copy

*\-o, \--read-only* mount the Hot Copy read-only

*\-c, \--changed-blocks* specify an alternate device to store changed blocks

*\-l, \--list* list active Hot Copies

*\-r, \--remove* remove specified Hot Copy device

*\-q, \--quota* specify free space quota for change blocks storage (default is 5%).  If your changed blocks storage device has less than or equal to this percentage of free space the Hot Copy will be aborted.

*\-s, \--show-hcp-device* print the Hot Copy device (/dev/hcpX) corresponding to the real block device given

*\-v, \--version* print version information about hcp command line utility and hcp device driver

*\-h, \--help* print help dialogue

*DEVICE* the block device to make a snapshot of.

*QUOTA* integer percentage of free space quota for changed blocks.

h3. EXAMPLES

Create a new Hot Copy session:

          hcp /dev/sdb1

Remove a Hot Copy session:

          hcp \-r /dev/hcp1

List available Hot Copy sessions:
        
          hcp \-l
      
Create a new Hot Copy session with a specified free space quota for changed blocks of 10%:

          hcp \-q 10 /dev/sdb1

Report bugs to [http://forum.r1soft.com]

h3. COPYRIGHT

Copyright 2008 - 2012 Idera, Inc. 

h3. SEE ALSO

[hcp-setup|LTR1D:hcp-setup], [hcp-device|LTR1D:hcp-device]