I have a very important server running Windows Server 2003 and my System partition is becoming too small, it's slowing down the machine. I have already tried all the cleaning stuff and transferring some "unimportant softs" on the "Saves" partition but it didn't help much at all. Is there a way to re-partition my hard-drive that will work on a 2003 Server, that's not too expensive and that could be used without turning the machine off. If there is no other way, then I'll have to reinstall the OS, but it will have to wait for the weekend. Thanks for your suggestions.
If it's the system partition you want to expand, as far as I know, there's no way around a reboot. Personally, I fire up a GParted Live CD [link] and resize the partition (as long as you have enough space on the disk).
If you're talking about a non-system disk, you can use diskpart.exe with no reboot. Proceed like this:
You can convert the disk to a Dynamic Disk, add more disks to the same pool and then add a second Dynamic Volume to the C:\ partition to increase its size.
http://www.petri.co.il/difference_between_basic_and_dynamic_disks_in_windows_xp_2000_2003.htm
The boot partition can be resized with Acronis Disk Director, from what I remember you do have to reboot if you re-size said partition.
Moo is wrong, I've checked, even if you convert to dynamic disk, you cannot expand the system volume. Only simple volume and spanned volume can be extended, though the system is simple volume, it cannot be extended. It will cause problem worse if you convert to dynamic disk, as no software can resize it. You'd better resize the partition in basic disk. I used disk director, it is the best server partitioning tool. If others have this problem, see this tutorial, then you'll know how easy to solve this problem by resizing with disk director
Use ExtPart. Free, simple and allows a live/online extend.
Has some limitations (NTFS format, Basic disk types), but even though it's a Dell driver, it works perfectly on other vendors' hardware. I've been using it to extend the disks on a bunch of legacy VMware VMs (on HP servers) for quite a while and have yet to encounter any issues.
If it is not using the entire disk, you could use diskpart.exe to extend it in size a bit more. By the way your question is phrased, I am assuming that is the case.
If the disk is 100% used, then your only option would be to move the data to a larger drive. This would not require a full re-install of the OS, but it would require down time.
The easiest way would be to clone the drive onto a large disk using something like Symantec Ghost.
If I remember correctly, diskpart will work only in special cases, namely when you have free space without any partitions on it, as it won't shrink other partitions.
Disk Director (or other tools like that) will happily do this when there is enough free space. It can take a lot of time though.
If downtime is a concern, I would copy the disk onto another bigger one with a better disk layout, as you can do most of this in a running system, at least with Acronis True Image.
Also, when you do anything with diskpart, Disk Director or anything like that, remember to have a up-to-date and and tested backup as it's easy to do something fatally wrong, both for you and for the tools.
To increase the partition size, you may try diskpart command line, which is free and provides by microsoft, but has some disadvantages, it is not the best tool to change the partition size.
To increase the partition size with third party partition software, you just need to drag and move on the disk map to shrink a data partition, after that, extend the system partition with the unallocated space.
If the system partition is NTFS, you can extend it without rebooting the 2003 server to save time, see more details how to increase partition size on server 2003
Use EASEUS partition master.
But you need to reboot the server and leave it offline for 2-3 hours