max partition size

carpman · Posted: Fri Dec 21, 2007 6:49 pm Post subject: max partition size

Hello, ok i have my areacs raid controller and 2 new hitachi 7k1000 750gb drives ready fro 64bit install.

I have one Raid 1 array that will house

/boot
/
/usr
/var
/opt
/home

also have a raid 0 for

/swap
/tmp
/usr/portage
/usr/src
/var/tmp
/opt/games
/mnt/scratch

this leave me with raid 1 600gb array for file storage, mainly image files for my photography. I am probably going to go with xfs but what i am not sure of is if should create 2 x300gb partitions as maybe one big 600gb partition is not efficient?

Also with DR xfs guide it says:

frostschutz · Advocate Joined: 22 Feb 2005 Posts: 2977 Location: Germany

When I broke the 500GB barrier, I switched to LVM2. Simply because it's a pain in the a... having to shuffle 500GB worth of data around only because you want to change the partition layout. With LVM2 and xfs it's a piece of cake. You need more space? Add some with LVM2 and then use xfs_grow to make this space available to your file system. No need to umount or reboot anything. Reducing space now, is a bit more complicated, because that's something where you always need to shuffle data, and xfs doesn't have a tool to shrink on the fly (yet), but it's still fairly easy to do by using the dump / restore tools of xfs.

Does it add overhead? Yes, but it's negligible even on older machines.

Regarding file system optimization and allocation groups: I never did any of that so I don't know if it's worth while. XFS is really bad with tons of small files, so instead I use reiserfs for ccache, /usr/portage, and /usr/src. I don't particularly like reiserfs, but it's extremely good with tons of small files, so that's what I'm using it for. And again, LVM makes it easy creating tons of small partitions for these 'exception' areas. Without LVM, I'd never use the partition layout I'm currently using, because the chance that you have to move some stuff around is just too high.

Using reiserfs, instead of xfs, for /usr/portage, will give you much more of a speed advantage than putting it on a faster disk (I assume your raid 0 is for speed). Of course doing both will be even better.

Also don't forget about backups. RAID is not a backup, no matter how many disks are allowed to fail.

carpman · Posted: Sat Dec 22, 2007 8:34 am Post subject:

Hello and thanks for reply, i have used lvm in the past but tired of it as resizing was pain.

I have pretty much got the size for system partitions worked out from current installs so need for resizing is not important. When i say use xfs i only meant for file storage array, i will be using mixture of ext3, reiserfs and xfs for system and home partitions.

My question is not really directed at system partition setup but at this huge 600gb array i have for file storage, which as said will be for my images which usually range from 2mb to 30mb and some 100mb (scans). I already have a file server for other files, iso music etc.

I have the file allocation trick for ages but never for partition this size, 1 allocation group per 4gb for 600gb partition is 153,600 !! surely this is not a realistic figure to use?

cheers
_________________
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frostschutz · Advocate Joined: 22 Feb 2005 Posts: 2977 Location: Germany

Hmmm, no idea. The default values that mkfs.xfs is using: