HOWTO: AIX support for R/W filesystem on USBMS

JFS2 Unsupported
Putting JFS2 on non-LVM block devices has been working for a long time. I​ wrote up how to put JFS2 on a ramdisk back at AIX 4.3.3. I lost the techdoc from back then, but IBM has a newer re-write dated 2008 here: http://www-01.ibm.com/support/docview.wss?uid=isg3T1010722

JFS2 requires the underlying system to tell it if something goes away, or for it to stay there as long as the filesystem is mounted. LVM does this for disk, and the ramdisk drivers do this as well (mostly because if the ramdisk fails, likely the system has failed). The key there is that with JFS2, the ramdisk pages are pinned.

I wrote up including performance on USB 1 and USB2 ports in January of 2010 HOWTO: JFS2 on USB device on AIX 5.3.11.1. Everything is fine, and dandy, even mount on boot, except it’s not supported by AIX Development.

JFS2 Problems
The problem for USB Mass Storage Devices is that the device can just go away unexpectedly. If a disk goes into deep sleep, or resets because of a loose connection, the JFS drivers do not get notified. So, they take writes, and JFS2 saves them up until it’s time to flush. It goes to flush, and the I/O channel is gone. Sometimes, this is just loss of everything in cache. If it’s an important file, then the system crashes.

​Because of that, we still cannot put LVM on a USB Mass Storage Device. This would take changes to notification of device availability, perhaps changes to the sync daemon, etc. Who knows, but there’s not been enough push from paying customers to make it a priority for AIX Development. Until that happens, don’t expect formal support for JFS2 on these devices.

UDF is the solution
AIX development supports read/write and even booting from USB Mass Storage Devices, but only with UDFS. The purpose is for writing a mksysb (system boot) image, or tar/cpio files, etc, and exists because of the RDX USB Internal Dock sold with some systems.
https://www.ibm.com/support/knowledgecenter/en/ssw_aix_61/com.ibm.aix.files/usbms_fileref.htm

​Boot support is provided as well: REF: ​http://www-01.ibm.com/support/docview.wss?uid=isg1IZ66737

More info on RDX USB Internal Dock. https://www.ibm.com/support/knowledgecenter/POWER7/p7hdt/fc1103.htm

RDX is just a hot-swap USB to SATA drive bay. Any current USB drive (USB3 is preferred due to performance), should work fine.

HOWTO: Create, Read, and Write UDF on AIX

Create bootable filesystem

  mksysb -eXpi /dev/usbms0

Create empty filesystem

  udfcreate -d /dev/usbms0

Create UDF 2.01 filesystem

  udfcreate -f3 -d/dev/usbms0

NOTE: UDF 2.01 supports a real-time filesystem. It’s still UDF, so don’t try to put a database, or a million files on there.

Access read/write

  mount -vudfs /dev/usbms0 /USBDRIVE

NOTE: The mksysb is a SPOT, plus a mksysb image, so adding files to the UDF will not make the restore huge.

USB Adapters on AIX
Add-in USB3 XHCI adapter for POWER8 is:

  • CCIN 58F9 – PCIE2 4-port USB3 adapter
  • FC EC45 and FRU 00E2932 for Low Profile
  • FC EC46 and FRU 00E2934 for full height.
  • driver is 4c1041821410b204 internal or 4c10418214109e04 PCIe

Add-in USB2 EHCI adapter for POWER7 is:

  • CCIN 57D1 – PCI-E 4-port USB2 adapter
  • driver is 33103500 integrated or 3310e000 PCIe
  • FC 2728 or FRU 46K7394

Add-in USB2 EHCI adapter for POWER6/POWER5 is:

  • CCIN 28EF – PCI 2-port USB2 adapter
  • FC 2738 or FRU 80P2994
  • Belkin F5U219 – exact same card without the sticker.
  • driver is 99172604 internal or 99172704 PCI

Original USB1 OHCI /UHCI adapter for POWER5 and earlier was

  • driver 22106474 on blades or c1110358 PCI
  • This device is not really available anymore.