Recently, an AIX administrator named Jon Buys talked about three tools he wishes that were available in Linux. Mainly, these technologies (not tools) are actually part of enterprise class UNIX environments in almost every case.
One was a tool to create a bootable system recovery disk. AIX calls the tool to do this makesysb; in my world – HP-UX – this is called make_tape_recovery. In HP-UX, this utility allows you to specify what part of the root volume (vg00) to save and other volumes. Booting the tape created from the make_tape_recovery utility will allow you to recreate the system – whether as part of a cloning process or part of a system recovery.
Another technology missing from Linux is the ability to rescan the system buses for new hardware. In Jon’s article, he describes the AIX utility cfgmgr. HP-UX utilizes the tool ioscan to scan for new I/O devices. Jon mentions LVM (which has its roots in HP-UX) but this does not preclude scanning for new devices (as any HP-UX administrator can attest).
Jon then discusses Spotlight (from MacOS X) and laments that it is missing from Linux. Linux has Beagle and Tracker, and all are quite annoying and provide nothing that locate does not – and on top of this, locate is present on AIX, HP-UX, Solaris, and others. I for one would like to completely disable and remove Spotlight from my MacOS X systems – Quicksilver and Launchbar are both better than Spotlight. In any case, all of these tools don’t really belong on an enterprise-class UNIX system anyway.
As for me, there are some more technologies that are still missing from Linux. One is LVM snapshots: while they exist in Linux, they are more cumbersome. In HP-UX (the model for Linux LVM) a snapshot is created from an empty logical volume at mount time, and the snapshot disappears during a dismount. In Linux, the snapshot created during logical volume create time (whatever for??) and then is destroyed by a logical volume delete. The snapshot operation should mirror that of HP-UX, which is much simpler.
Another thing missing from Linux which is present in every HP-UX (enterprise) system is a tool like GlancePlus: a monitoring tool with graphs and alarms (and the alarms include time-related alarms).
Consider an alarm to send an email when all disks in the system average over 75% busy for 5 minutes running. This can be done in HP-UX; not so in a standard Linux install. There are many others as well.
Personally, I think that Performance Co-Pilot could fill this need; however, I’m not aware of any enterprise class Linux that includes PCP as part of its standard supported installation. PCP has its roots in IRIX from SGI – enterprise UNIX – and puts GlancePlus to shame.
Perhaps one of the biggest things missing from Linux – though not specifically related to Linux – is enterprise-class hardware: the standard “PC” platform is not suitable for a corporate data center.
While the hardware will certainly work, it remains unsuitable for serious deployments. Enterprise servers – of all kinds – offer a variety of enhanced abilities that are not present in a PC system. Consider:
- Hot-swappable hard drives – i.e., hard drives that can be removed and replaced during system operation without affecting the system adversely.
- Hot-swappable I/O cards during system operation.
- Cell-based operations – or hardware-based partitioning.
For Linux deployment, the best idea may be to go with virtualized Linux servers on enterprise-class UNIX, or with Linux on Power from IBM – I don’t know of any other enterprise-class Linux platform (not on Itanium and not on Sparc) – and Linux on Power may not support much of the enterprise needs listed earlier either.
What are your thoughts?
UNIX Administratosphere 
I would love to see a way to create a bootable system recovery DVD/BD/HDD image of a Linux server. It would make restoring a backup much easier than installing a base system the restoring the newest/correct backup.
I built a Linux server about six months ago that has hot-swappable HDDs on a SATA card. I can hot swap the drives without adversely affecting the system, but it may adversely affect the drive if not unmounted.
There are 2 softwares that I use to make system recovery: SystemImager (http://wiki.systemimager.org/) and Mondo Rescue (http://www.mondorescue.org/).
I was thinking about HP drives I’ve seen in the past: some could be pulled during system operation and the system will not even notice (the HP AutoRAID was in this category); others could be pulled without affecting the hardware, but the system had to be prepped first and the drive quiesced (the HP “Jamaica Drive” – a set of mirrored drives – was like this).
I was talking about both: whether the system needs to be aware or not, the drive can still be removed and replaced while up and running – without crashing the system or destroying hardware.
What? Hot swappable hard drives have been standard on any higher end PC based servers for years, only some very cheap low-end PC servers (or desktops acting as servers) have non-hot-swappable SATA drives. Now, hot-swapping RAM or CPUs is something that still belongs to to the “real enterprise servers” and mainframes.
What I’d like to see in PC/Linux from pSeries/AIX world is the logging facility and “errpt” instead of the current ad-hoc method of logging system and hardware errors to syslog in some random format.
Things may be different now, but at one time the supposedly “hot-swappable” drives in Compaq rack servers were suspected of being unsafe: that is, a hot-swap could bring the server down.
With the HP-9000s we never had that problem – and in the AutoRAID, you didn’t even have to notify the server that a disk was out (or in!). Just swap and enjoy the goodness…
Dude. Mondoerescue is what you need. it’s free and it works great. I have quite a few machines being imaged every week. I have spun up dev boxes and clones using it. It just works. I even used it when I moved a system from using partitions to LVM.
Also, there is glanceplus for Linux. but it sucks. Get collectl. It provides a great wealth of info.