PCI Hot Plug User's Guide 2.5.1

2.1.1.3 PCI Hot Plug Disconnect operation

• All device drivers running on the system must support PCI Hot Plug functions (PCI Hot Plug safe drivers). PCI Hot Plug safe drivers should support the following Solaris OS DDI/DKI entries.
  • DDI_DETACH:detach(9E)

  If any PCI Hot Plug unsafe driver (not PCI Hot Plug safe) is loaded, the PCI Hot Plug disconnect procedure could fail. For detailed information about supported device drivers, refer to "PCI cards with support for PCI Hot Plug" in the "PCI Hot Plug User's Guide I/O device edition".

• The device must not be in use or opened by any user or system process. The following description shows some examples of disk and network card. Please refer to "PCI Hot Plug User's Guide I/O device edition" for detail.
  

1. Disk

   If any mounted disk exists on the outgoing PCI card, the PCI Hot Plug disconnect operation will fail. To avoid this problem, please unmount the disk as follows:
   

   # umount pathname of the mount point

   If any dump device or swap device exists on the outgoing PCI card, the PCI Hot Plug disconnect operation will fail.
   To avoid this problem, please stop using the disk as follows:
   

   # swap -d device name

   # dumpadm -d device name

   Disk space resources should be recalculated when the above configurations are changed.

2. Network card

   If any activated network device exists on the outgoing PCI card, the PCI Hot Plug disconnect operation will fail.
   Even though the RCM deactivates the network device automatically during PCI Hot Plug disconnect operations, the network devices on the outgoing PCI card should be manually deactivated as follows:

   # ifconfig interface down
   # ifconfig interface unplumb

• Multi path I/O configurations are recommended to make I/O devices available for PCI Hot Plug operations. For example, network devices or disk devices can be set up in multi path I/O configurations. For details about I/O multipathing, refer to "PCI Hot Plug User's Guide I/O device edition".
  The necessity for Multi path I/O configuration is explained below using the cases of disk and network cards.
  
  

1. Disk
   It is not possible to umount the root file system or any other file system that is vital to the user. To solve this problem, the administrator can use the I/O Multipathing feature to set up alternate paths to the crucial devices, or use other disk mirroring software to mirror the crucial file systems.
   
2. Network card
   If the deactivated interface is the primary network interface for the system (the IP address of defined in the file /etc/nodename), all basic network applications like ftp(1), rsh(1), rcp(1), rlogin(1), telnet(1) will not function and NFS client and server operations are also affected. The user must use I/O Multipathing software to solve this problem. In addition, when the System Management Console (SMC) is used, functions of the SMC become unavailable if a network interface to the SMC is disconnected. This issue should be avoided in the same manner.

• The Path Redundant capability of I/O Multipath can be utilized to maintain uninterrupted access to the media in case of a PCI card disconnection. An I/O device can be configured such that it can be accessed from two different PCI cards. Even if one of the PCI cards is disconnected, the I/O device remains accessible. However, I/O performance may be degraded because the number of redundant paths is reduced.
• The following error message may appear in Solaris 9 OS despite of successful PCI Hot Plug disconnect operation. When the READY LED, ONLINE LED and ALARM LED are turned off at the PCI slot of the outgoing PCI device, or cfgadm(cfgadm_pci(1M)) shows the Receptacle field of outgoing PCI device as 'disconnected', the operation is successful. This bug is fixed with Solaris 9 OS patch 112958-03 as Sun BugID: 4798214.

  Message

  cfgadm: Hardware specific failure