Migrating from SDDPCM to AIXPCM (the easy way)

For a while now, IBM have diverted their efforts in storage multipathing from SDDPCM to the default AIX PCM [1]. This brings a few advantages, but specifically for me, it means the driver is now updated as part of the AIX system maintenance, and is no longer something I need to maintain separately. All significant functionality that SDDPCM provides, can now be provided by the default AIX PCM driver. Additionally, SDDPCM is not supported on POWER 9 hardware.

For those currently using SDDPCM, removing the driver can be somewhat complicated, and even more so when the boot LUN (rootvg LUN) is being managed by SDDPCM. Buried deep in the Multipath Subsystem Device Driver User’s Guide is a command called manage_disk_drivers. The manage_disk_drivers command can be used to display a list of storage families, and the driver that manages or supports each family. This allows us to easily (with a reboot if you boot from an SDDPCM managed device) switch the driver from SDDPCM to AIXPCM (or vice versa).
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disk_size.sh – Quick look at disk details

I’ve been doing many AIX server migrations lately. Some which involve taking a mksysb and restoring, others which involve presenting LUN’s from a SVC and then doing a migratepv. The latter can result in a large number of disks presented on the host, so I wrote a quick basic script which gives me the details that I need – hdisk name, size, vg, pvid and serial number.

Maybe someone out there will find it useful.
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Upgrading your AIX environment using multibos

If you haven’t clued on by now, AIX is my operating system of choice. I’m sure there are many arguments for and against, but looking at it from a systems administrator view point, it’s second to none. Anyway, that’s a story for another time. What I’m writing about today is patching your AIX installations using multibos. Now before I get started, I’ll stress two points:

1) Chris Gibson has already written two great (and far more in depth) articles on multibos, which I recommend reading before going any further (Links: here and here).
2) This blog of mine serves two purposes; To share some of the things I come about during my sysadmin activities and secondly also a dumping ground for documents I write for myself. This post is the latter, as multibos isn’t something that I use daily (maybe a few times a year), and really, who’s going to remember all those syntax switches 😛

Now, assuming you’ve read both articles, I don’t need to go into the benefits of multibos and I’ll dive straight into the how. I’ll be working on upgrading an AIX instance running 6100-05-01-1016 to the latest ML which at the time of writing is 6100-06-04-1112
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Mounting external USB NTFS drive to FreeNAS

This is a quick post on how to mount an external USB NTFS formatted hard drive (or memory stick) to FreeNAS. All that’s needed is to load the fuse driver, but it had me stumped for a bit until I found it in a forum post.

First things first, let’s plug in our drive and find out the device ID FreeNAS assigns it.

# dmesg
umass1: <ASMedia AS2105, class 0/0, rev 2.10/1.00, addr 3> on uhub4
da1 at umass-sim1 bus 1 target 0 lun 0
da1: <ST950042 0AS 0002> Fixed Direct Access SCSI-0 device 
da1: 40.000MB/s transfers
da1: 476940MB (976773168 512 byte sectors: 255H 63S/T 60801C)

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