True but that is not recommended to move partitions in the partition table. Most professional partitioning agents will give forceful warning that such action may lead to data loss.The only ideally accepted way is to create a new partition and format it then use tools to move data between them.
According to Maxtor, Seagate and possibly others, Linux/Unix systems can have partitions 2, 3, and 4 all of type extended at the same time. I have only gone as far as partitions 2 & 3 being extended and was able to create 15 logicals in each but I noticed a marked speed of access decrease when two extended’s exist. If you get of copy of ultimate Linux - the concise guide to system resources, it talks about using the 4 ide channels to host 4 hdd with a maximum fanout of drives as 4 primary each on an independant drive, and 12 extended’s with 17 logicals in each.
Part of the trouble with understanding hdd’s, is that Windows prior to XP had a choice of 2 primary or 1 primary and 1 extended with 16 logicals max. Thusly limiting the system to 4 primary and 64 logicals.
Windows XP, Vista, and I presume windows 7 too can now access all four primaries but can only handle 1 of then being extended which is probably where you are basing info on. Thusly fanout under windows only increased by 8 (72 in total now). External USB drives are becoming the norm as each USB can handle 16 devices per channel with the same power as an internal hdd.
well its not “in the middle” sda5 is, as you know at the start of the extended, but now I’m just nitpicking.
no, in fact I don’t think it is nitpicking, Why is it that sda5 can not be deleted without changing sda6 to sda5 , sda7 to sda6 , sda8 to sda7 and after this if you create a new swap partition that is now sda8, and yes, I do understand that if this problem started “in the middle” of the extended there would be an excuse.
Hey.
Remember somewhere Guys we were discussing booting from the extended partition with the boot flag on it and I mentioned how I had Fedora switch the boot flag even though it was in a logical. Well I just installed F14 for fun and it moved the flag from sda2 to logical sda8 where F14 is installed.
Disk /dev/sda: 160.0 GB, 160041885696 bytes
240 heads, 63 sectors/track, 20673 cylinders, total 312581808 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x93900d8b
Device Boot Start End Blocks Id System
/dev/sda1 63 136327589 68163763+ 7 HPFS/NTFS
/dev/sda2 136327651 312576704 88124527 5 Extended
/dev/sda5 136327653 142319834 2996091 82 Linux swap / Solaris
/dev/sda6 142319898 180120779 18900441 83 Linux
/dev/sda7 180120843 261184769 40531963+ 83 Linux
/dev/sda8 * 261184833 312576704 25695936 83 Linux
Just though I would drop this in here./;
According to Maxtor, Seagate and possibly others, Linux/Unix systems can have partitions 2, 3, and 4 all of type extended at the same time. I have only gone as far as partitions 2 & 3 being extended and was able to create 15 logicals in each but I noticed a marked speed of access decrease when two extended’s exist. If you get of copy of ultimate Linux - the concise
Forget Maxtor and Seagate, give me a quote from linux.
Hey.
Remember somewhere Guys we were discussing booting from the extended partition with the boot flag on it and I mentioned how I had Fedora switch the boot flag even though it was in a logical. Well I just installed F14 for fun and it moved the flag from sda2 to logical sda8 where F14 is installed.
Code:
Disk /dev/sda: 160.0 GB, 160041885696 bytes
240 heads, 63 sectors/track, 20673 cylinders, total 312581808 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x93900d8bDevice Boot Start End Blocks Id System
/dev/sda1 63 136327589 68163763+ 7 HPFS/NTFS
/dev/sda2 136327651 312576704 88124527 5 Extended
/dev/sda5 136327653 142319834 2996091 82 Linux swap / Solaris
/dev/sda6 142319898 180120779 18900441 83 Linux
/dev/sda7 180120843 261184769 40531963+ 83 Linux
/dev/sda8 * 261184833 312576704 25695936 83 Linux
Just though I would drop this in here./;
You are saying then , that this boots fine with the flag on a logical, sda8?
It doesn’t matter … that’s why it seems so irrelevant. You can set the flag on all logicals with fdisk if you like. Nobody cares about that flag - except Fedora and openSUSE in a way I cannot figure out.
you can try this link that kinda pushes the limits high to over 240 partitions.
Partitions, logical vs primary
or
How to install and boot 145 operating systems in a PC - JustLinux Forums
My copy of ultimate Linux is currently out on loan so I can’t scan the instructions right now.
and since USB so much is changing you might what to read this from seagate
Seagate first 3TB HDD performance and temperature measurement - waybeta
Indeed it does
caf,
Try to remove that flag with fdisk and reboot Fedora. What difference does it make? (none).
I took you literally, so removed it and didn’t put the flag anywhere else so it looks like this
Device Boot Start End Blocks Id System
/dev/sda1 63 136327589 68163763+ 7 HPFS/NTFS
/dev/sda2 136327651 312576704 88124527 5 Extended
/dev/sda5 136327653 142319834 2996091 82 Linux swap / Solaris
/dev/sda6 142319898 180120779 18900441 83 Linux
/dev/sda7 180120843 261184769 40531963+ 83 Linux
/dev/sda8 261184833 312576704 25695936 83 Linux
It boots fine !
Can you explain this please.
That wouldn’t be necessary today, since the libata driver is not limited to 15 devices anymore. I believe it would work though. Actually a Unix primary partition also contents logical units (called ‘slices’) and Linux creates and numbers the devices after the last logical of the extended partition. So if you count BSD disklabels, I could say that I have 3 and sometimes 4 extended partitions. Like the extended partition, the Unix primary itself is not ‘mountable’ and only contains the slices.
Part of the trouble with understanding hdd’s, is that Windows prior to XP had a choice of 2 primary or 1 primary and 1 extended with 16 logicals max. Thusly limiting the system to 4 primary and 64 logicals.
Part of the trouble is using Windows, any version.
I knew you had Grub in MBR 
But to the others (listening to those who tell them to leave the MBR untouched) don’t try that ! rotfl!rotfl!
Ask me if I give a rats a-ss about this…lol!
But what are Fedora playing at - because if you ask me it’s super silly the way they have that happening.
Did someone say openSUSE follows this practice? Because I never have seen this.
You want to experiment? Fdisk, extended menu (experts only), option “f” is “fix partition order”.
Do it from a live, and reboot afterwards.
Now, this is not an experiment with soda water. It is your disk with valuable data… I would do a
full image of the original disk, just in case. Or learn how it works on a smaller disk.
I’m happy to look into this. at this moment time is an issue , but soon.
You don’t read my posts. I keep saying that it doesn’t make sense for months… years (?). openSUSE does the same, except that it let you set/unset the bootflag. But it’s 2 clicks away from main menu in the ‘advanced boot options’ (or something like that) and by the time it takes ‘normal’ users to look there, openSUSE has already overwritten their MBR with a generic bootcode. If they unfortunately uncheck all bootflags … what do you think happen when they reboot ? Feierabend!
IMHO YaST developpers should make the priority be booting Linux - even another distro - raher then preserving Windows. That’s the key.
Here’s a funny one in french out of many: Grub pour les nuls
Sorry for my negligence in post reading.
But I installed openSUSE 11.4 twice last week in that same sda8 partition. It didn’t put boot flag on sda8, but it is preserved on sda2 extended. So the behaviour is not the same as Fedora.
No it’s not exactly the same behaviour, but it might produce the same result. openSUSE let you set/unset the bootflag on its root patrition whether it’s primary or logical. Great! And by default it aims to write a generic bootcode to the MBR. Now what’s the difference between having the bootflag set on primary partition and have it set on a logical one with a generic MBR?
And by default it aims to write a generic bootcode to the MBR
But does it.
Whenever I install openSUSE, it always has boot form MBR disabled, offering to boot from extended.
If extended is missing/not present, it always defaults to root, still listing boot form MBR as disabled.
On 2010-10-10 19:36, please try again wrote:
>
> techwiz03;2236051 Wrote:
>> I have only gone as far as partitions 2 & 3 being extended and was able
>> to create 15 logicals in each but I noticed a marked speed of access
>> decrease when two extended’s exist.
> That wouldn’t be necessary today, since the libata driver is not
> limited to 15 devices anymore.
The old driver used for pata could accept 64 partitions (primaries + extended + logical), while the
driver used for scsi accepted only 16. Then libata was used for both pata and sata drives, meaning
all were limited to 16. And now, we finally have a implementation (pushed by Novell, who was
“pushed” by people like me) which is not limited in the number of partitions per disk.
–
Cheers / Saludos,
Carlos E. R.
(from 11.2 x86_64 “Emerald” at Telcontar)