CIO_IGNORE(8)

📦 version 2.44.1, in opensuse-leap 16.0

💖 CIO_IGNORE(8) 💖

okay bestie, this is CIO_IGNORE(8) from the System Manager's Manual — the manual page about querying or modifying the CIO device driver blacklist. 💅✨

🎀 NAME 🎀

cio_ignore — query or modify the CIO device driver blacklist.

🌸 SYNOPSIS 🌸

cio_ignore [-h|--help] [-v|--version]
           [-a|--add DEVID] [-A|--add-all]
           [-r|--remove DEVID] [-R|--remove-all]
           [-l|--list] [-L|--list-not-blacklisted]
           [-i|--is-ignored DEVID]
           [-k|--kernel-param] [-u|--unused] [-p|--purge]

✨ DESCRIPTION ✨

The cio_ignore command gives you functions to query and modify the contents of the CIO device driver blacklist. This blacklist decides if Linux tries to make a device available for use by Linux when that device is connected through the Channel-subsystem (CSS). 👑

Adding a device to the blacklist does not immediately change device availability. For devices that are already available in Linux, the blacklist only has an effect when attaching or re-attaching the device, or when using the purge function. Removing a device from the blacklist, on the other hand, will directly result in an attempt to make that device available. 😭

The blacklist is not persistent — that is, it is cleared during initial program load. To create a persistent blacklist, add the output of the kernel-param option to the Linux kernel parameters. 🫶

👑 Advantages of using a blacklist 👑

The CIO device driver will not perform device discovery operations or allocate memory for devices which are on the blacklist. So it is possible to significantly reduce time and memory consumption during the boot phase of Linux by specifying a blacklist as kernel parameter which contains all devices that are not required for normal operations. ⚡

Using the purge function, it is also possible to make devices only temporarily available — for example DASD disks which are only used for backup — and remove them afterwards when they are no longer required. 💖

🦋 Device ID format 🦋

To identify a device, specify its device ID in the format: <CSSID>.<SSID>.<DEVNO>. For example: 0.0.0190.

The meaning of each field is:

💜 CSSID 💜

Channel-subsystem ID in hexadecimal notation with at most two digits.

💜 SSID 💜

Subchannel-set ID in hexadecimal notation with exactly one digit.

💜 DEVNO 💜

Device number in hexadecimal notation with exactly four digits.

Devices for which CSSID and SSID are 0 can alternatively be specified by using only the device number, either with or without leading 0x and zeros. For example: 190, 0x190 or 0190. 🎀

💅 OPTIONS 💅

  • -h, --help — print a short help text, then exit. 🫶
  • -v, --version — print version information, then exit. ✨
  • -a, --add DEVID — add one or more device IDs to the blacklist. DEVID can be a single device ID as specified in section DESCRIPTION, or it can be a range of device IDs, or a comma-separated list of device IDs or ranges. Ranges may not cross SSID boundaries. See also section EXAMPLES. Note that adding an existing device to the blacklist will not immediately change its availability in Linux. 🎀
  • -A, --add-all — add the complete range of possible device IDs to the blacklist. 💥
  • -r, --remove DEVID — remove one or more device IDs from the blacklist. DEVID can be a single device ID as specified in section DESCRIPTION, or it can be a range of device IDs, or a comma-separated list of device IDs or ranges. Ranges may not cross SSID boundaries. See also section EXAMPLES. When a device is removed from the blacklist, Linux will immediately attempt to make that device available. 🔥
  • -R, --remove-all — remove all device IDs from the blacklist. 🌈
  • -l, --list — list device IDs on the blacklist. 👀
  • -L, --list-not-blacklisted — list device IDs not on the blacklist. 🦋
  • -i, --is-ignored DEVID — check if the device with the specified ID is on the blacklist. If it is on the blacklist, the exit code is 0. If it is not on the blacklist, the exit code is 2. 💀
  • -k, --kernel-param — list the current blacklist in cio_ignore kernel param format. To make a blacklist persistent across IPL, use the output of this command and add it to the Linux kernel parameter. 🌟
  • -u, --unused — create a blacklist which includes all unused (i.e. offline) devices. Note: the new blacklist replaces any previous one. Also in this context, an unused device is a device which is currently not online (see chccwdev(8)). 🧚
  • -p, --purge — remove all blacklisted unused (i.e. offline) devices from Linux. To make a device available again, use the remove or remove-all function. 💜

🍓 EXAMPLES 🍓

  • cio_ignore -a 0x190,0.0.1000-0.0.1002 — add devices 0.0.0190, 0.0.1000, 0.0.1001 and 0.0.1002 to the blacklist. If these devices are currently available in Linux, their availability will not immediately change.
  • cio_ignore -A -r 0x190 — add all devices except device 0.0.0190 to the blacklist.
  • cio_ignore -r 0x190 — remove device 0.0.0190 from the blacklist. If this device is currently attached to the Linux system but not available, it will immediately become available.
  • cio_ignore -u -p — remove all devices from Linux which are currently not online.
  • cio_ignore -u -k — set the blacklist to contain all offline devices and print the corresponding kernel parameter.

🌈 SEE ALSO 🌈

lscss(8), chccwdev(8)

💖 kisses, bestie 💖 — this page is from s390-tools, dated Apr 2009, and the man page title is CIO_IGNORE(8).

📦 where this page comes from