Partitioning Scheme

dTr · Posted: Mon Feb 06, 2006 6:57 pm Post subject: Partitioning Scheme

I have 2 250GB hard drives and I want to make sure I get the most out of them when I partition them. At the moment I have -
WinXP : 12GB
WinProgs : 75GB
WinDocs : 10GB

I am thinking of repartitioning my gentoo system so that I have-
/
/Home
/Tmp
/Usr
/Usr/Portage
/Var
along with shared directories formatted in ext2 so that both linux and winxp can access -
/mnt/Music : 40GB
/mnt/Pictures : 10GB
/mnt/Programming : 10GB
/mnt/Documents : 10GB
Possibly the last two could be combined.

My question is, what partitions have a suggested minimum size, for example, I think that I need to make /var at least 5GB so that I can compile larger programs (OOo2 etc). Should I split var into more partitions?
I am thinking about using reiser4 for /Tmp /Usr/Portage and /Var because I have heard that it handles smaller files more efficiently. Is that a good idea, I have heard that reiser might not be 100% stable, is that true? The rest of my system would be ext3 unless anyone can persuade me to switch!
Any other input would be appreciated.

Twist · Guru Joined: 03 Jan 2003 Posts: 414 Location: San Diego

Honestly with filesystems the way they are nowadays, I believe you are overthinking this a lot. The only (marginal) benefit to a heavily partitioned tree is you isolate fragmentation over time. On the other hand, you severely limit your flexibility with hard partitions, since it requires restructuring the entire mess when you run out of space on X or Y partition. 20 years ago I partitioned everything up, nowadays I tend to do "operating system" and "userland" partitions for Linux, and leave it at that.

So mine are typically

/
/home
..and that's it, except on the RARE occasion I break out /tmp.

Total problems doing that for me? zero. ext* is remarkably resilient and not prone to the hyper fragmentation that NTFS is. On the off chance you really do back into a fragmentation wall in 5 years or whatever that would take...fire up another disk, mount, cp -aR and you have a fully unfragmented new disk.

-Twist

NeddySeagoon · Posted: Mon Feb 06, 2006 7:20 pm Post subject:

dTr,

You can overdo partitioning - and you dont mention swap.
You don't say if you have SATA/SCSI or IDE (PATA) drives. With a large number of partitions it matters.
SATA/SCSI can have at most 15 partitions, IDE (PATA) may have 63.

Reiser 3.6 is stable but when it breaks you will need a backup. All the ext2 recovery tools work on ext3, which makes ext3 a good bet. Hopefully, your partition mount points will have all lowercase names /usr not /Usr or things will break badly.

Were it not for windows, I'd suggest you try raid0. That operates both your drives in parallel for almost twice the data rate of a single drive but windows cannot read linux software raid. If you are using a SATA fakeraid controller, you may be in luck. Linux can use some of these.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

dTr · Posted: Mon Feb 06, 2006 8:26 pm Post subject:

both drives are indentical sata drives, I considered raid but i've never attempted it before and I don't really know what i'm doing so I think i'll leave it. I decided to use different partitions to limit fragmentation, I thought that having my portage tree in a different partition mounted as reiser might improve both performance and fragmentation issues. I also decided to use seperate partitions for music, pictures and documents (and programming) so that I could mount them as ext2 and read/write to them under both windows and linux. I understand that I am limited to 15 partitions on each drive but I don't think thats a problem really as I am not planning on using more.

P.S if anyone has any links to raid howtos please post them here. I have an nvidia4 motherboard if it helps

NeddySeagoon · Posted: Mon Feb 06, 2006 8:45 pm Post subject:

dTr,

It depends what you want from your raid system. the hardest to set up is Linux and Windows on the same fakeraid system.
You will need to reinstall both Windows and Linux.

Linux kernel raid Just Works but you cannot share with Windows.

google for dmraid to see how the Windows/Linux raid is done.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

dTr · Posted: Tue Feb 07, 2006 1:45 pm Post subject:

I was under the impression that raid was handled by the hardware, not software. I probably won't use raid, I will just split the partitions across both disks. Do you think, given my reasoning, that this partition setup is a good one?

NeddySeagoon · Posted: Tue Feb 07, 2006 7:26 pm Post subject:

dTr,

I think its too many partitions. Read up about Logical Volume Manager. It provides 'on the fly' resizing of partitions.
I'm not sure if you have to allocate whole discs or partions to it, so it may not want to share with windows. It makes life very easy when a partition runs out of space.

Raid can be handled by hardware or software, so there are 3 sorts of raid, as well as the raid levels.
There is hardware raid - this requires a special plug in card. Its not on domestic PC motherboards or even high end workstations.

There is software raid, as provided by the linux kernel. Its slower than hardware raid as the kernel has to do the device management. Hardare raid appears as a single device - the raid card does the rest.
There is fakeraid. This is often advertised as SATA RAID on domestic PC motherboards. Its a variairion on software raid, in this case, the software is provided by the BIOS, hence the unkind nickname of fakeraid. Many windows users don't realise this is what they have.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

mauldus · Posted: Wed Feb 08, 2006 10:18 am Post subject:

If you want super simple and low risk, just keep windows on one drive and linux on the other. Have windows already installed and just install grub to boot it.

Or, take the plunge and wipe windows out.

Software raid0 (striping) and you'll have ~460G to play with (back up your data, if one drive fails, it's all gone).

The other options of makeing windows and linux play nicely here with some combination of raid will get tricky so read up on it before you dive in.

As far as partitions, /boot swap / and /home are fine. I would stick with ext3. There's a nice ext3 thread going right here for some tweaking of the filesystem. I didn't realize how versitile it is. I use data journaling and directory indexing for my filesystems. I like the security it gives me. On the other hand, I use xfs on my array for mythtv because of the huge files and I'm not really worried about losing them. So it depends on your needs.

If you want to improve portage, I'd slice off no more than 5G for /var/tmp and just make it ext2 with maybe a small block size. Why do you need the cpu over head for journaling a partition that holds temp data anyway. Perhaps link /var/tmp back to /tmp.

The problem with this is the more journals for the cpu to keep up with, I think, would negate any performance you'd get from using a specific filesystem for several partitions. So I'd keep the number down to a minimum but separate your data from the OS.

dTr · Posted: Thu Feb 16, 2006 1:18 pm Post subject:

would a higher number of partitions really increase cpu usage? surely when data is written to the hard drive one journal would have to be written to no matter how many partitions there are.
My main aims for my partition setup are to allow read/write access to music etc from both winxp and gentoo, to split gentoo partitions so that all heavily changed directories are in separate partitions from / and this would also allow for different filesystems on partitions with different types of files (small/large, not/written often etc).
As far as I can see, my requirements would logically lead to a partition setup of-
Linux:
/ ext3
/boot ext3
/home ext3
/tmp ext2(?)
/usr/portage reiser4
/usr/portage/distfiles xfs(?)
/var/tmp ext2
/swap
WinXP:
System ntfs
WinProgs ntfs
WinDocs ntfs
Shared
Music ext2
Pictures ext2
Documents ext2

I have chosen ext2 for the shared directories becuase they can be mounted and written to in winxp using fsdriver www.fs-driver.org.

Penguin of Wonder · Posted: Thu Feb 16, 2006 6:22 pm Post subject:

In my opinion, thats still more paritions than you probably need, but i would use XFS instead of Reiser4. Which ever one you pick though, i'd stick with it for simplicity's sake.

If i read you right your not going to be sharing /home, /tmp, or /var, why not just make those XFS or Reiser4 as well. They'll be quicker than using ext2 or 3. I usually just make my /boot ext2, since there are no more than 30M there usually anyway, there won't be any real benefit to having any other filesystem.

Good luck keeping all of that straight though!
_________________
My Linux Blog

AMD64 3700+
2G DDR 3200 Ram
320G HDD

Keruskerfuerst · Posted: Thu Feb 16, 2006 7:50 pm Post subject:

I would partition as follows:
/boot, swap and /(root).
I am using xfs for /boot and /(root).
Lately I have done a install of Slamd64 (64-bit Slackware) on my computer with reiserfs4. The filesystem is incredibly slow.

Gentree · Posted: Sun Apr 09, 2006 7:18 pm Post subject:

I dont see much sense in anything but ext2 for /boot

I like to keep / under 4.3 GB so I can easily back up the system to DVD (or elsewhere) and can quicky be copies when defrag is needed. This means pulling off all directories that need lots of space.

I have used R4 extensively for two years and find it very good, mainly because of atomic writes that survive crashes and power-outs without losing data and lenghty fscking around. It's also fast and efficient (unless your running a 586!)

I put all my portage stuff on one partition , about 6GB. To do this I edit /etc/make.conf and change port_tmpdir logfir and distdir to be on the same partition. This takes the load off /var which I keep on /

I prefer vfat for sharing with win and do not recommend letting windows anywhere near ext3 . Windows is a liability, if we cannt avoid it all together at least keep it well confined.

I do go for rather a lot of smaller partitions just because this makes reorganising and backup easier.

Assuming you go for small root partition, I'd recommend making room for a clone.

Gentoo often has a package throw a cat amoungst the pidgeons and the best way to keep running is to have a line in grub that can boot to a clone of your system that is kept upto date.

I can clone my / in about 2mins with dd , so if an update goes wrong I just reboot , no hassle. I've too often been caught out and spent, sometimes days, trying to fix the results of a broken package update.

That's my 2cts (euro) so you've had it from all angles now. If you're not confused you should be :wink:

_________________
Linux, because I'd rather own a free OS than steal one that's not worth paying for.
Gentoo because I'm a masochist
AthlonXP-M on A7N8X. Portage ~x86

Penguin of Wonder · Posted: Sun Apr 09, 2006 7:22 pm Post subject:

Gentree · Posted: Sun Apr 09, 2006 8:19 pm Post subject:

It is not a resource "issue" , it is purposefully designed that way. Recognising that modern processors are very often near idle and that the IO speed was a more significant factor in overall performance H. Reiser took the strategy of placing more load on the CPU. This seems to work rather well. There is no way your are going to "see" the slow down of the cpu overhead on a 64 bit machine.

The slowness he may have experienced is possibly due to fragmentation after several months of usage. This was a major issue on reiserfs and present to a lesser extent on R4 since there is still no defrag tool.

The simplest way to defrag is to copy or tarball the entire partition (hence my suggestion of reasonable partition sizes above).

This limitation I find more than offset by the other advantages of R4.

_________________
Linux, because I'd rather own a free OS than steal one that's not worth paying for.
Gentoo because I'm a masochist
AthlonXP-M on A7N8X. Portage ~x86

Penguin of Wonder · Posted: Sun Apr 09, 2006 8:31 pm Post subject:

That makes it a tough choice then. Do you think they'll come out with a defrag tool? If not I think I'll stick with XFS.
_________________
My Linux Blog

AMD64 3700+
2G DDR 3200 Ram
320G HDD