Storage Checkpoint administration

Storage Checkpoint administrative operations require the fsckptadm utility.

See the fsckptadm(1M) manual page.

You can use the fsckptadm utility to create and remove Storage Checkpoints, change attributes, and ascertain statistical data. Every Storage Checkpoint has an associated name, which allows you to manage Storage Checkpoints; this name is limited to 127 characters and cannot contain a colon (:).

Storage Checkpoints require some space for metadata on the volume or set of volumes specified by the file system allocation policy or Storage Checkpoint allocation policy. The fsckptadm utility displays an error if the volume or set of volumes does not have enough free space to contain the metadata. You can roughly approximate the amount of space required by the metadata using a method that depends on the disk layout version of the file system.

For disk layout Version 5 or prior, multiply the number of inodes (# of inodes) by the inode size (inosize) in bytes, and add 1 or 2 megabytes to get the approximate amount of space required. You can determine the number of inodes with the fsckptadm utility, and the inode size with the mkfs command:

  # fsckptadm -v info '' /mnt0
    UNNAMED:
      ctime      =  Thu 3 Mar 2005 7:00:17 PM PST
      mtime      =  Thu 3 Mar 2005 7:00:17 PM PST
      flags      =  largefiles, mounted
    # of inodes      =  23872
    # of blocks      =  27867
    .
    .
    .
    # of overlay bmaps   =  0
  # mkfs -m /dev/vx/rdsk/sharedg/vol0 
  # mkfs -F vxfs -o \ 
    bsize=1024,version=5,inosize=256,logsize=65536,\
    largefiles /dev/vx/rdsk/sharedg/vol0

In this example, the approximate amount of space required by the metadata is 7 or 8 megabytes (23,872 x 256 bytes, plus 1 or 2 megabytes).

For disk layout Version 6 or 7, multiply the number of inodes by 1 byte, and add 1 or 2 megabytes to get the approximate amount of space required. You can determine the number of inodes with the fsckptadm utility as above. Using the output from the example for disk layout Version 5, the approximate amount of space required by the metadata is just over one or two megabytes (23,872 x 1 byte, plus 1 or 2 megabytes).

Use the fsvoladm command to determine if the volume set has enough free space.

See the fsvoladm(1M) manual page.

  # fsvoladm list /mnt0
  devid					size							used				avail							name
 	0					20971520							8497658				12473862							mnt1
 	1					20971520							6328993				14642527							mnt2
 	2					20971520							4458462				16513058							mnt3