Most of the storage arrays now-a-days provides the feature of dynamic LUN expansion. This feature allows you to grow your existing volume on the fly without affecting existing data or I/O. Dynamic LUN expansion increases the capacity of the physical storage. You must then make Solaris aware that the device has grown, and if a file system resides on the device, it must also be grown.
Before LUN expansion
1. Here is the disk that was used to create the SVM mwtadevice as seen in the format command output :
# format
< . . . . >
97. c7t600A0B80002FBC5D00001AC952B3294Cd0 [SUN-LCSM100_F-0670 cyl 51198 alt 2 hd 128 sec 64] svm-vol
/scsi_vhci/ssd@g600a0b80002fbc5d00001ac952b3294c
format> partition
partition> print
Part Tag Flag Cylinders Size Blocks
2 backup wu 0 - 51197 199.99GB (51198/0/0) 419414016
2. Here is the sequence of commands that originally created the metadevice and UFS file system on this LUN :
# metainit d100 1 1 c7t600A0B80002FBC5D00001AC952B3294Cd0s2 # newfs /dev/md/rdsk/d100 # mkdir /svm-vol # mount /dev/md/dsk/d100 /svm-vol # df -k /svm-vol Filesystem kbytes used avail capacity Mounted on /dev/md/dsk/d100 206532277 204809 204262146 1% /svm-vol
After LUN expansion
In this example, 50GB are added to the existing volume on the storage array. The steps involved in adding the space in SVM are :
1. Delete the metadevice. Doing so has no effect on the data.
2. Expand the disk device.
3. Recreate the metadevice.
4. Mount and grow the file system.
Step 1: Delete the metadevice
Document the metadevice information properly and then delete the metadevice.
# metastat -p d100
d100 1 1 /dev/dsk/c7t600A0B80002FBC5D00001AC952B3294Cd0s2
# umount /svm-vol
# metaclear d100
d100: Concat/Stripe is cleared
Step 2 : Expand the disk device
# format c7t600A0B80002FBC5D00001AC952B3294Cd0
selecting c7t600A0B80002FBC5D00001AC952B3294Cd0: svm-vol
format> type
AVAILABLE DRIVE TYPES:
0. Auto configure
< . . . . >
Specify disk type (enter its number)[19]: 0
c7t600A0B80002FBC5D00001AC952B3294Cd0: configured with capacity of 249.99GB
[SUN-LCSM100_F-0670 cyl 63998 alt 2 hd 128 sec 64]
format> partition
partition> 2
Enter partition id tag[backup]: [Enter]
Enter partition permission flags[wu]: [Enter]
Enter new starting cyl[0]: (0 was the value prior to the expansion)
Enter partition size[524271616b, 63998c, 63997e, 255992.00mb, 249.99gb]: $
partition> label
Ready to label disk, continue? yes
partition> quit
format> quit
Step 3 : Re-create the metadevice
# metainit d100 1 1 /dev/dsk/c7t600A0B80002FBC5D00001AC952B3294Cd0s2
d100: Concat/Stripe is setup
Step 4 : Mount and grow the file system
# mount /dev/md/dsk/d100 /svm-vol
# growfs -M /svm-vol /dev/md/rdsk/d100
# metastat d100
d100: Concat/Stripe
Size: 524271616 blocks (249 GB)
Stripe 0:
Device Start Block Dbase Reloc
/dev/dsk/c7t600A0B80002FBC5D00001AC952B3294Cd0s2 0 No Yes
Verify the df -h output to confirm the filesystem space has increased.
# df -k /svm-vol
Filesystem kbytes used avail capacity Mounted on
/dev/md/dsk/d100 258167212 256009 255845881 1% /svm-vol
The LUN on the storage array has been expanded. Additional space has been given to the Solaris disk device. The metadevice has been recreated to pick up the new size. The UFS file system has been grown to take advantage of the added space. The operation is complete.