The lsdsk command lists ASM-visible disks. You can restrict the output to only those disks that match a pattern, which can include wildcard characters and slashes. You can run this command in either the connected mode or the non-connected mode. In the connected mode, the command retrieves disk information from the V$ and the GV$ tables. In the non-connected mode, the command scans disk headers to retrieve the disk information. Unless you specify the -i flag, the lsdsk command runs in the connected mode when you are connected to an ASM instance. Here is an example of the lsdsk command.
ASMCMD> lsdsk
/dev/raw/raw1
/dev/raw/raw3
...
ASMCMD> lsdsk -d data -k
Total_MB  Free_MB  OS_MB  Name       Failgroup  Library  Label  UDID  Product  Redund   Path
    8189     6961   8189  DATA_0000  DATA_0000  System                         UNKNOWN  /dev/sdc1
    8189     6961   8189  DATA_0001  DATA_0001  System                         UNKNOWN  /dev/sdd1
    8189     6950   8189  DATA_0002  DATA_0002  System                         UNKNOWN  /dev/sde1
You can also specify the following flags with the lsdsk command:

• --statistics: Displays the READS, WRITES, READ_ERRS, WRITE_ERRS, READ_TIME, WRITE_TIME, BYTES_READ, BYTES_WRITTEN, and the PATH columns of the V$ASM_DISK view.
• -p: Displays the GROUP_NUMBER, DISK_NUMBER, INCARNATION, MOUNT_STATUS, HEADER_STATUS, MODE_STATUS, STATE, and the PATH columns of the V$ASM_DISK view.
  
• -t: Displays the CREATE_DATE, MOUNT_DATE, REPAIR_TIMER, and the PATH columns of the V$ASM_DISK view.
  
• -g: Selects from GV$ASM_DISK_STAT, or from GV$ASM_DISK if the --discovery flag is also specified. GV$ASM_DISK.INST_ID is included in the output.
  
• --discovery: Selects from V$ASM_DISK, or from GV$ASM_DISK if the -g flag is also specified. This option is always enabled if the Oracle ASM instance is version 10.1 or earlier. This flag is disregarded if lsdsk is running in non-connected mode.
  
• --suppressheader: Suppresses column headings.
  
• -I: Scans disk headers for information rather than extracting the information from an Oracle ASM instance. This option forces non-connected mode.
  
• -G: Restricts results to only those disks that belong to the group specified by diskgroup.
  
• -M: Displays the disks that are visible to some but not all active instances. These are disks that, if included in a disk group, cause the mount of that disk group to fail on the instances where the disks are not visible.
  
• --candidate: Restricts results to only disks having membership status equal to CANDIDATE.
  
• --member: Restricts results to only disks having membership status equal to MEMBER.
  
• pattern: Returns only information about the specified disks that match the supplied pattern.
• -d: along with another flag such as -t, limits the output to a specific disk group, as shown here:

ASMCMD> lsdsk -t -d dgrp1
Use the help lsdsk command to get information about all the options of the lsdsk command.

You can also attach the -l flag to any other flag to make ASM retrieve the information directly from the file headers instead of the V$ views. For example:
ASMCMD> lsdsk -lk

The preceding command gets detailed disk information from the disk headers. If the ASM instance isn’t available for some reason, you can still get the information you need by letting ASM extract the information from the file headers. You can get information for a specific disk group by using the -d flag with any of the other flags, as shown here:
ASMCMD> lsdsk -t -d dgrp1
The previous lsdsk command gets detailed information about the disks in disk group dgrp1.