Tuesday, June 3, 2008

Installing Mandriva; adding new Western Digital HDD

I spent half weekend biking and other half installing Mandriva Linux (version 2008 "One" , spring) on my "server box", the one i replaced capacitors on. Also, on monday I got new SATA hard drive.

The biking deserves its own blog post with photos, though i didnt see or photo anything particularly interesting. Thats the thing with biking, you make bigger distance, but do much less photographing.

So i'll blog about Mandriva and new hard drive.

Installation was very smooth. However there is several nasty quirks in mandriva:
1: Mandatory reboot after fsck. Severety: VERY high. Fix: VERY trivial.
When i disconnected one of hard drives to troubleshoot some hardware issue, and tried to boot, it tried to fsck partitions on removed disk, fsck failed, and it asked for admin password or ctrl-d for continue. After ctrl-d it just reboots. After exiting admin mode, it reboots. Happens in failsafe startup as well. Very annoying.

Advantage of reboot after fsck, if any, seems very, very dubious. Linux only needs reboot when you modify the kernel. It is not windows which needs reboot after everything, and not OS X which needs reboots after many big installs.
Linux always did configure things the right way. So on Linux you normally have to reboot only when it is real, physical necessity, i.e. only after you change kernel.

Disadvantage is extremely massive for newbies: it makes system impossible to boot after one drive has been removed or failed. If course there is workaround - when it asks to repair manually, enter root password, then edit /etc/fstab . Or try init 3 .
Editing is very tricky when you do not have any normal console editor (i made a copy of fstab then used grep to filter out lines that i didnt want) and thats far beyond newbie. Especially when [s]he has 1 pc or no internet, and cannot get online to ask.
Negates the "linux is more reliable than windoze" entirely.
Solution is trivial: locating the idiotic commit that added this reboot behavior, and removing it.

2: It didn't detect my ram size properly, not even with explicit kernel option. I have 1280MB on this machine, thats 1024+256 MB. Mandriva's kernel detected 884mb = 1024-128-12 . I have AGP aperture size set to 128mb, so that might be it. Definately a bug, old ubuntu detected size correctly regardless of AGP aperture size.
Thats no big issue for me, I will rebuild kernel anyway, or install vanilla kernel. But would be bad for newbie.

Some linux tips, while i remember:
Mount drives with noatime,nodiratime option. That disables updating of access times on files (the time when file was last read). It gives much faster, less energy consumption system. In some cases, it gives >2x speedup.
Without this option, when you read file, the access time has to be written to disk. And it has to be written even if file is in buffer. That can more than double overhead for reading lot of tiny files.
I never need access times, and do not have any applications that uses them. Maybe back in seventies and eighties, access times did correspond to user accessing the file and were useful for cleanup and pinpointing unused files, but today, having all sorts of applications that read lot of files automatically and dont disable access time update, and having really cheap hard drives (i got 500gb for 75 Euro), access times are entirely meaningless.
More on access times: http://kerneltrap.org/node/14148

Now about the hard drive. I got western digital wd5000aaks drive (internal), 500GB , SATA2 capable, 3 years warranty.
Minor quirks>:
To connect it to old SATA (also known as SATA 1500 or SATA 150) controller, i had to add jumper (a tiny connector thingy) between jumper pins 5 and 6 . OEM package does not include jumper. You can ask for jumper (and bolts to install drive, too) at shop, any self respecting shop has surplus of those and will provide for free.
For pin numbering, consult label on hard drive. Its second column from the left when label is up and connectors are to the left of jumper slot. (the pin numbering starts from the right, dunno why) . BTW, my label didnt have print about the sata1.
NOTE: if you have different hard drive, do NOT connect jumper based on this blog post. Google for your specific hard drive!

By funny coincidence, some girl i know got same hard drive on same day. Besides jumper, she had to enable SATA in BIOS (some BIOSes have it disabled by default). Search for it in BIOS, check "integrated peripherals" section first.

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