Grow LUN presented on Linux host

Linux and Unix-Like Red Hat
1

Hi,

I have a SAN LUN of 550 GB created as an ext3 partition of the entire lun and need to make the lun and partition larger... 600 GB

 
[root@jdcijisprod ~]# fdisk -l /dev/sdj
Disk /dev/sdj: 590.5 GB, 590558003200 bytes
255 heads, 63 sectors/track, 71797 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
   Device Boot      Start         End      Blocks   Id  System
/dev/sdj1               1       71797   576709371   83  Linux

I have read that once you extend the LUN on the array side you can umount the LUN, run fsck and use the resize2fs on the host side.
Can anyone verifyif this is correct and if there are any potential dangers
in doing this.

2

You'll need to resize the partition as well before doing the resize. The more flexible way of doing dynamic resizing is to use LVM instead of partitions (just an fyi). If you had used LVM, you could have added a new LUN space to a volume group (VG) and expanded the logical volume (LV) and done the filesystem resize without having to umount or reboot or anything...

3

Thanks cjcox, if I resize the partition would I lose the current data?

4

I recommend you take a full backup before you do such activity, just in case.