RMAN 10G NFS Mount Options
We backup our Oracle databases using RMAN and then write the backup pieces out to an NFS share. This has always worked well, but RMAN started complaining that the NFS share was not mounted with the correct options when we upgraded to Oracle 10G. After some poking around in the docs I finally came up with a set of mount options that work.
Vfstab entry on a Solaria 8 box:
nfsserver.domain.com:/path/to/remote/mountpoint /local-mountpoint nfs 0 yes rw,bg,intr,hard,timeo=600,wsize=32768,rsize=32768
Manual mount on a Solaris 8 box:
mount -o rw,bg,intr,hard,timeo=600,wsize=32768,rsize=32768 nfsserver.domain.com:/path/to/remote/mountpoint /local-mountpoint
According to the docs, the options on a Linux box are pretty much the same, except you would add the following:
nfsver=3,tcp
Creating Linux Partitions for CLARiiON
Creating a properly offset slab of disk for Linux systems on your CLARiiON is not just a matter of creating a partition using the default fdisk values. The reason for this is that disk management utilities for Intel based systems generally write 63 sectors of metadata directly at the beginning of the LUN. The addressable space begins immediately after these initial sectors causing the CLARiiON to cross disks, especially when writing larger IO because it doesn’t match up with the stripe element size (usually 64k).
To get around this, you have to align the partition in such a way that it will start writing data on a sector that will mesh up nicely with the stripe element size. In this case, 128. Below is an example of how I create partitions on our CLARiiON for Linux systems. Check out the EMC Best Practices for Fibre Chanel storage white paper for more detail.
/sbin/fdisk /dev/emcpowera Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel Building a new DOS disklabel. Changes will remain in memory only, until you decide to write them. After that, of course, the previous content won't be recoverable. The number of cylinders for this disk is set to 39162. There is nothing wrong with that, but this is larger than 1024, and could in certain setups cause problems with: 1) software that runs at boot time (e.g., old versions of LILO) 2) booting and partitioning software from other OSs (e.g., DOS FDISK, OS/2 FDISK) Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite) Command (m for help): n Command action e extended p primary partition (1-4) p Partition number (1-4): 1 First cylinder (1-39162, default 1): Using default value 1 Last cylinder or +size or +sizeM or +sizeK (1-39162, default 39162): Using default value 39162 Command (m for help): x Expert command (m for help): b Partition number (1-4): 1 New beginning of data (63-629137529, default 63): 128 Expert command (m for help): w The partition table has been altered! Calling ioctl() to re-read partition table. Syncing disks.
X11 Forwarding Broken on Solaris
If you’re running Solaris 8 or 9 and an upgrade results in broken SSH X11 forwarding, the problem may be Sun’s socfs bug. The symptom will be SSH’s failure to set the $DISPLAY variable and an error in your system log looking something like this:
Jun 3 09:40:24 servername sshd[26432]: [ID 800057 auth.error] error: Failed to allocate internet-domain X11 display socket.
To fix this, you can either install Sun’s latest socfs patch for your version of the OS, or simply force sshd into IPv4 mode by doing the following:
Edit you sshd_config file, adding the following:
# IPv4 only
ListenAddress 0.0.0.0
Edit your sshd startup script to issue a “-4″ to sshd on start:
case “$1″ in
’start’)
echo ’starting ssh daemon’
/usr/local/sbin/sshd -4
;;
Restart sshd, and that should pretty much do it… Enjoy.
