Creating a ramdisk in Solaris (updated)

Updated 10 Nov 2015 Read time 1 min 13 sec(s) (2671 views). Solaris

Why ramdisks?. ramdisks can be used by developers and sysadmins as a way to prove that an application performance issue is not related to the underlying storage

ramdiskadm is used to administer ramdisk pseudo devices on the Solaris operating environment.

Note: ramdisks are non-persistent across reboots and data will be lost

Warning: Do not create ramdisks that consume large amounts of memory as this could also cause you significant performance problems.

Synopsis

To add a new ramdisk
```
ramdiskadm -a  name size [g|m|k|b]
```
To remove a ramdisk
```
ramdiskadm -d name
```
To list current ramdisks:
```
ramdiskadm
```

Example

Update: This procedure also works for Solaris 11

Create a 2GB ramdisk named rdisk1

# /usr/sbin/ramdiskadm -a rdisk1 2g
/dev/ramdisk/rdisk1

Listing available ramdisks

# ramdiskadm
Block Device                   Size  Removable
/dev/ramdisk/rdisk1     21474836480    Yes

Create a filesystem on the ramdisk

# newfs /dev/ramdisk/rdisk1

newfs: construct a new file system /dev/ramdisk/rdisk1: (y/n)? y
Warning: 2688 sector(s) in last cylinder unallocated
/dev/ramdisk/rdisk1:    41942400 sectors in 6827 cylinders of 48 tracks, 128 sectors
        20479.7MB in 427 cyl groups (16 c/g, 48.00MB/g, 5824 i/g)
super-block backups (for fsck -F ufs -o b=#) at:
 32, 98464, 196896, 295328, 393760, 492192, 590624, 689056, 787488, 885920,
Initializing cylinder groups:
........
super-block backups for last 10 cylinder groups at:
 40997024, 41095456, 41193888, 41292320, 41390752, 41489184, 41587616,
 41686048, 41784480, 41882912

Mount the ramdisk, for this example on /u01/data01
```
# mkdir -p /u01/data01
# mount /dev/ramdisk/rdisk1 /u01/data01
```
Note: Remember to change the owner:group of the mounted ramdisk if needed
Once finished you can unmount and remove using:
```
# umount /u01/data01
# ramdiskadm -d rdisk1
```