Ubuntu KVM

I installed KVM on my Ubuntu desktop. Documentation made this easy. I then grabbed a KVM virtual appliance, ran: sudo kvm va-lapp-root.img and watched it boot.

Cloud Computing, Hotel California

Rehash of slashdot: Is cloud computing the Hotel California of tech?

SLES kernel updates remove prior kernel

After experiencing a problem at work and verifying it on Novell's forum, I want to make it known that:

When "SUSE Linux Enterprise Server" installs a kernel update, it deletes the kernel on which it is running.

I've never seen something this stupid. What if the old kernel doesn't boot? Why not keep at least one old version available? I've never seen a Unix do this. We're going to write a script:

$ ./cya.sh --before # back up the old kernel somewhere
$ rug upgrade
$ ./cya.sh --after # reinstall the old kernel 

Did Suse always have this problem or did Novell break it?

Sun Storage 7410

I mentioned earlier that Sun seems to be offering the same old SAN as EMC. This is the case for their 6580 but not for their 7410. I mentioned two problems from the EMC and below is how Sun addresses them.

• LUN Tetris: The Sun Storage 7410 stripes data across all SATA drives using ZFS to serve blocks in the case of iSCSI or files in the case of NFS. This similar to how NetApp uses WAFL. If you configure ZFS-NSP (no single point of failure) with a minimum of two drawers of disk, then redundant copies are written so you can loose more drives (an entire shelf?).
• SP Bottle Neck: Sun has the same problem here. One smart SP and several disk only drawers. However, you can max a 7410 to 288T.

Other 7410 features:

• Contains Solid State Flash drives which ZFS manages to improve performance in areas that need it which is similar to Compellent's automated tiered storage.
• Does not offer fiber channel access so the only way to read blocks from it is iSCSI.
• All extra features (snapshots, clones, etc) are included without separate licenses (unlike NetApp)
• Allows admin to SSH into Solaris based SPs for management OR use a Web Client (Ajax).
• A virtual box simulator let's you try out the management system.

NetApp

I mentioned earlier that NetApp seems to be offering the same old SAN as EMC. This is only partially true. I mentioned two problems from the EMC and below is how NetApp addresses them.

• LUN Tetris: NetApp stripes either SATA or SAS drives across a large RAID6 and aggregates them together so that you have large storage pools of a single type, e.g. one for SATA and one for SAS. You can then compute the amount of available disk by subtracting from a total number. You can also have nothing but SATA and the large stripe can address performance problems associated with SATA, however getting IOPS stats first is a good idea. Else a small pool of SAS could address the need for fast disk.
• SP Bottle Neck: NetApp has the same problem here. One smart SP and several disk only drawers. They do offer PAM modules which add 256G (depending on which head) of cache to increase performance. When upgrading SPs remember that changing out an SP is easier if you have zoned by port number, not WWN.

A FAS3140 will max out at 420T of raw capacity with all SATA. So SP upgrades seem further away for my organization's current usage. Regardless, this design is not as elegant as grid storage and if I'm going to consider it they'll need to offer a good price.