newkomer to linux, new custom pc, need help/suggestions (long)

[darbotic]

Re: newkomer to linux, new custom pc, need help/suggestions (long)

Alright, I found an old 40GB hard drive this morning and got that installed on my other computer. I'm in the process of downloading the Kubuntu LiveCD right now so when that completes I'll run fdisk and try my hand at aligning cylinders and adjusting the heads and sectors to see if I can get it partitioned properly. The machine I'm using this on is an old athlon 64 3.2 GHz processor with 1GB RAM. I'll post updates when I get to them so I can get more input and suggestions if I need them, or if the community feels there is more information I should know about.

BTW I just noticed I haven't thanked anyone, thus far, for the information they have provided so THANK YOU!!! You guys have been great, patient, and understanding. I hope to be able to make everything work out the way I want it to.

[oshunluvr]

Re: newkomer to linux, new custom pc, need help/suggestions (long)

Since you're building a new system, I'd really consider my suggestion to install windows to one drive and then grub-pc to the other drive. It's by far the easiest way to dual (aka "duel" ) boot.

[Ole Juul]

Re: newkomer to linux, new custom pc, need help/suggestions (long)

Since you're building a new system, I'd really consider my suggestion to install windows to one drive and then grub-pc to the other drive. It's by far the easiest way to dual (aka "duel" ) boot.

I would echo that. At the price of drives, or availability of old ones these days, it is really worth while to just use separate drives for each OS. Think of it, you can trash your Kubuntu installation as much as you like and not have to worry about Windows even knowing about it. You can still access the Windows drive seamlessly from the Kubuntu drive. A separate drive is freedom!

[darbotic]

Re: newkomer to linux, new custom pc, need help/suggestions (long)

Oshun and Ole: point taken. I may just order another sataII hdd so that way linux has it's own committed drive. But, I guess 1TB is ample space to partition it off. I haven't decided yet. But, because I've made such a big deal about all this I still want to know in case I still decide to run it off my ssd or buy a separate ssd to run it off of. Thank you for your inputs.

Update on my kubuntu installation: Every time I boot from the livecd I get about 8 messages that pop saying the same thing,
"The server failed the authenticity check (identi.ca).
The certificate authority's certificate is invalid.
The root certificate authority's certificate is not trusted for this purpose.
The certificate cannot be verified for internal reasons."

Is that normal?

Second, I opened Konsole and wiped the drive, then partitioned off the drive and wrote the changes. However, when I booted back up off the livecd and when into Konsole and did a sudo fdisk -luc /dev/sda it's showing 255 heads/ 63 sectors. When I go to sudo fdisk -H 32 -S 32 -uc /dev/sda and then p to print the results it shows on 32 heads/sectors that my partitions are aligned based on that. should it see the 32 heads/sectors at the very beginning? I thought I read somewhere that someone else was having this problem as well but I haven't been able to locate that particular post on whatever forum it happened to be on.

[dibl]

Re: newkomer to linux, new custom pc, need help/suggestions (long)

I don't recall seeing the type of error messages from the Live CD that you're seeing -- I wonder if you got a good burn. FAQ #1 in my signature is all about that topic.

On the fdisk usage, note that changes to the partition table are not written until you do "w" and hit the enter key. Then it should "write" them, and upon a reboot that's what you should see from the fdisk -l output. Step through the Torturetest guide one more time and review the sequence. Don't forget that after "n" comes an entry for the type of partition -- I think your choices are "1" or "2" and you need "1". Then the next step is the critical one -- where you enter cylinder "2" as the beginning of the first partition.

[darbotic]

Re: newkomer to linux, new custom pc, need help/suggestions (long)

I followed the guide to burning the iso, slowest setting possible. When I booted from the disk I actually did a disk check to check for disk errors and ram test to make sure everything was ok. Both tests passed so I assumed everything was alright (although I did take note of your faq post saying that it wasn't 100% reliable).

I did partition and w command to write the partitions before I rebooted to check the alignment. I will, as per suggestion, go back over TortureTests guide. I'll see if it's any easier for me to follow as I'm actually doing it. I had followed vbgunz' guide and it all made sense to me so that's why I decided to use that one.

[darbotic]

Re: newkomer to linux, new custom pc, need help/suggestions (long)

Ok so I'm having some problems getting TortureTest's guide to work for me. I'm doing everything as it says but I keep getting error messages and I'm not sure what to do. I'll lost my command and give you the results:

me: sudo fdisk -H 32 -S 32 /dev/sda
output: WARNING: DOS-compatible mode is deprecated. It is strongly recommended to switch off the
mode (command 'c') and change display units to sectors (command 'u').

If I disregard that message and continue on with the steps...

me: o
output: Building a new DOS disklabel with disk identifier 0xc8056082.
Changes will remain in memory only, until you decide to write them.
After that, of course, the previous content won't be recoverable.

Warning: Invalid flag 0x0000 of partition table 4 will be corrected by w(rite)

WARNING: DOS-compatible mode is deprecated. It's strongly recommended to switch off the
mode (command 'c') and change display units to sectors (command 'u').

[Snowhog]

Re: newkomer to linux, new custom pc, need help/suggestions (long)

me: sudo fdisk -H 32 -S 32 /dev/sda

You didn't follow the guide correctly. The command above is incorrect. It should have been:

sudo fdisk -H 32 -S 32 -cu /dev/sda

Assuming that /dev/sda is the drive/partition you are working with. The -cu tells fdisk to:

-c (Switch off DOS-compatible mode and -u (give sizes in sectors instead of cylinders).

[darbotic]

Re: newkomer to linux, new custom pc, need help/suggestions (long)

^^ thank you. However I still get the error regarding the invalid flag 0x0000

[darbotic]

Re: newkomer to linux, new custom pc, need help/suggestions (long)

actually, I'm looking at TortureTest's guide and there is no -cu command. He's adjusting cylinders, not sectors so no -cu

[dibl]

Re: newkomer to linux, new custom pc, need help/suggestions (long)

Don't worry about the "DOS-compatible mode deprecated ..." error message. That stuff is 100 years old ....

[darbotic]

Re: newkomer to linux, new custom pc, need help/suggestions (long)

Sorry guys, I'm wracking my brain here. I just don't get it. If I follow vbgunz guide I understand how to partition by sectors but I can't get it to save 32 heads/sectors. If I follow TortureTest's guide I can get it to save to the 32 heads/sectors, but he only says how to partition only one partition. For some reason I don't understand how to calculate how many cylinders I will need in order to have the amount of space I want. Because this computer is quite dated, I was going to allocate 10GB to a boot partition, 25 GB to the files, and 2GB for a swap (placing the swap as the last partion as I've read it's the best place for it to be).

I don't know, maybe I'm overthinking it (which I tend to do to EVERYTHING), but I don't understand this at all.

[oshunluvr]

Re: newkomer to linux, new custom pc, need help/suggestions (long)

I can't figure out what exactly it is you're trying to do - format the old 40GB drive?

What makes you think you need to change the sectors/heads from default?

fdisk automatically aligns with sector boundaries unless you change it.

I'd like to know where you read that about swap because I've always read the exact opposite - swap should be partition #1.

@DIBL - fdisk tip: after you use fdisk, you can usually use the new partition right away without rebooting. All you need to do is run partprobe and if it doesn't generate an error message you're good to go!

[Ole Juul]

Re: newkomer to linux, new custom pc, need help/suggestions (long)

I can't figure out what exactly it is you're trying to do - format the old 40GB drive?

That's what I was thinking. My eyes are glazing over here. I have a feeling that there are some perhaps inappropriate preconceived notions, because I've never heard of such a to-do before - and I've been formatting drives since MFM and RLL.

[dibl]

Re: newkomer to linux, new custom pc, need help/suggestions (long)

but he only says how to partition only one partition.

To make a second partition, instead of accepting the default ending cylinder (the last one) on the first partition, you must enter a cylinder number. The number you need use is 1 less than the beginning cylinder for the next partition*. Then after you do "t" and enter 83 to make the first one a Linux partition type, you press "n" to start the process for the second partition. You don't press "w" until after you've made the last one you want, because that writes the entire partition table.

* The math is indeed fairly confusing, just get your calculator out (or use kcalc if you're running KDE). As it says in the vbgunz writeup, in this CHS scheme, 1024 sectors make a 512K cylinder, 2 cylinders make a megabyte, and 1024 megabytes make a gigabyte (as usual). So, suppose you want the first partition to be a 12G partition for the OS, and then you want a following swap partition of about 2G. The first cylinder of your first partition is 2, and you can use your calculator to multiply 12G x 1024 to see that the partition will be 12,288 megabytes in size. Each megabyte is 2 cylinders so you need 12,288x2=24,576 cylinders. But, if you divide that number by the 512K cylinder size, you see it divides evenly (48), so that particular cylinder really needs to be the beginning of your next partition. Therefore you will set the end of the first partition to cylinder 24,575. Then after you set the type to 83, you do "n" again, and "p" to make it primary, and this time the partition number is "2" and the beginning cylinder is 24,576. Then you use your calculator again to figure out about how many cylinders will make the 2G partition, and then you adjust the ending cylinder number up or down as needed so that the following cylinder will be aligned (aka evenly divisible by 512) for the beginning of the third partition. Remember, it's only the beginning cylinder that needs to be 512k aligned -- ending cylinder numbers are irrelevant.

Note that since you started the partition on cylinder #2, and trimmed one off the total 24,576, you're really 3 cylinders/1.5M short of a full 12G partition. Hopefully you're setting the partition sizes liberally enough that such a minor deviation from the full size is not important. If it were, for some reason, then you would increment the ending cylinder up to one cylinder less than the next cylinder number that is evenly divisible by 512, which would be cylinder (25,088 - 1) = 25,087.

See?


@Ole, for Linux OS, a SSD needs to be partitioned manually for efficient performance and longest life. GParted is not (yet?) able to automatically account for the alignment of partition boundaries to erase blocks on the SSD. http://forums.anandtech.com/showthread.php?t=2069761

So OP is practicing his fdisk technique on an old hdd to learn how to set partition start "cylinders" to 512K block boundaries.

p.s. Hopefully we are all aware that there are not actually any cylinders, tracks or heads on a SSD -- we're just making use of the legacy LBA drive control scheme, and fdisk to arrange the writing and erasing of the SSD in an optimal manner.