August 2011 Archives

As I want to test an IP multipathed iSCSI storage configuration under Solaris 10 and 11 I wanted to set them up in Oracle VirtualBox. It was more or less easy.

Please do not forget to install the VirtualBox guest tools, otherwise the guest will crash as soon as the host system "steals" CPU cycles.

On text-only installs, mount the CD image like this (Solaris 10, CD is IDE master):

# mount -F hsfs /dev/dsk/c0t0d0p0 /mnt

On Solaris 11, the CD was attached to controller "7" target "1" (SATA, Port 1)

# mount -F hsfs /dev/dsk/c7t1d0p0 /mnt

Then:

# pkgadd -d /mnt/VBoxSolarisAdditions.pkg

If you accidentally upgraded your root zfs pool (which is not recommended until it is supposed to be done from Oracle) do not forget to update your boot signature,  your boot archive and your grub installation -

but do not reboot before having done this, otherwise the system won't boot any more.

Don't upgrade the root pool! You won't be able to repair your system when booting from the actual Solaris 10 boot CD (09/10) as the root pool cannot be mounted then. The following steps are to make sure that your system will at least boot when you did the upgrade accidentally.

Example:

Since Kernel patch/update 144501-19, Oracle now puts zpool version 29 and zfs version 5 into production.

One visible change is the more detailed status when doing a scrub or a resilver operation:

# zpool status
  pool: rpool
 state: ONLINE
 scan: scrub in progress since Mon Aug  8 16:18:21 2011
    1.98G scanned out of 3.66G at 50.7M/s, 0h0m to go
    1.98G scanned out of 3.66G at 50.7M/s, 0h0m to go
    0 repaired, 54.13% done
config:

        NAME        STATE     READ WRITE CKSUM
        rpool       ONLINE       0     0     0
          c1t0d0s0  ONLINE       0     0     0

errors: No known data errors

My "day-book" of my Ubuntu experiences as a day-by-day system can be found here:

http://southbrain.com/south/articles/me-and-my-desktop-ubuntu-1104.html

The article will grow and be split in multiple ones.

As you know, kissmetrics' tracking algorithm is based on the ETag resource sent along with every document from http servers. Its normal use is to distinguish cached documents from new versions, if the document to be delivered has altered a new ETag is generated. In web caches every cached resource is stored with its ETag.

For a request on a resource stored in the web cache a http header line like

If-None-Match: "H33jh3gggIU§gug3kjhgHhjbkc3"

will be added to the request which means "please send out the document only if its ETag is no longer H33jh3gggIU§gug3kjhgHhjbkc3".

kissmetrics generates ETags as User-IDs to be tracked and every site which uses kissmetrics to analyze web traffic data will include a small kissmetrics.com-request in their web site. The web browser cache will cache this little resource along with its ETag which is NOT its calculated ETag but the kissmetrics "user id". So on every site with a kissmetrics "bug" the request gets done with the

If-None-Match: "your_kissmetrics_user_id"

And voilà, you're tracked. Deleting cookies does not help. You have to clear your cache in your web browser after every site visited. Not very useful.

A possible solution would be to use a web proxy like squid which can easily filter out the "ETag" headers. So web browsers will use the "If-Modified-Since:"-method to make web servers to deliver documents only if they have changed. This will not work on most dynamic web sites however as web application programmers often forget to set and to honor this request header (using the last changed timestamp of the displayed data for example).

I will try it.

I'll begin on Wednesday. No more Macintosh, no more Windows - I chose Ubuntu 11.04 on a Fujitsu Siemens Esprimo PC with an Intel Core 2 Duo CPU running at 2,1 GHz. 4 GB RAM and a 500 GB Western Digital Enterprise Storage Hard Disk.

Not an expensive choice - I spent 150 Euros for the old PC, the new RAM and the new hard disk.


Will I be able to work day by day with this machine? Doing business? Watching movies? Playing games? Writing letters? Browsing the Internet? We'll see!