Partition Manager Help (v2.37.06) What is partition table, MBR, IPL? Saving and Restoring MBR Creating a new partition Formatting partition, supported file systems Things, that you should do before installing a new OS Compact Boot Manager Advanced Boot Manager Virus detection and hints Running DOS from the second hard drive Command line options Links to additional help Contacting author and copyrights
What is partition table? Partition table is located in the first sector of every hard disk. It has information about sizes and locations of partitions on the disk. What is partition? It is a piece of disk space marked to belong to some operating system. For example, your C: drive resides in the partition of type BIGDOS. Most disks have one partition, but some people want to have more than one operating system on their computers and therefore, have to divide their disks into different partitions. That's why partition table also keeps an indicator of the currently 'Active' partition - the one from which the computer boots. When you turn on your computer BIOS loads into memory the first sector from hard disk, called MBR (Master Boot Record). In addition to partition table, this sector contains an IPL (Initial Program Loader) - a piece of code that searches partition table for an 'Active' record and loads in memory boot sector of the corresponding operating system. Standard IPL would simply load a boot sector without any messages or questions. And this is good if you have only one operating system, but when you have more then one, you need something more sophisticated. For example, IPL that comes with this program can ask user at boot time which operating system he want to boot and will remember the selection, so that the next time it boots from the same OS. Partition table is limited to maximum 4 entries. This program gives you an option to have up to 31 bootable partitions if you install Advanced Boot Manager. Links to additional information and help
Saving and Restoring MBR Saving you MBR is the first thing you have to do before playing with this program. First of all create a bootable floppy disk and copy this program to floppy. Than save your MBR to a file. You can do it by using S command in interactive mode or by running program from the command line: part -s a:\saved.mbr If something goes wrong, you can always restore the original MBR by running the command: part -l a:\saved.mbr If you are using the same floppy with more than one computer be careful not to put MBR from one hard disk to another. It will do no harm, but you may have a few minutes of panic thinking that you have lost all your files, before you figure out what happend. So, make sure that you give distinctive names to the files with saved MBRs. But even if you do load the wrong table it will most likely become RED, because partition settings will conflict with the current hard disk geometry.
Selecting active partition To make partition active you can press SPACE in the interactive mode or from the command line: part -p print partition table part -a n where n is a partition number If you have installed an IPL then you can press SPACE on the active partition to make it inactive and when you reboot computer it will try to boot from the second hard disk, or from a floppy.
Advanced Boot Manager With Advanced Boot Manager you can have up to 31 bootable partitions. It keeps its own partition table in the separate space on the disk. When you boot the computer the first part of Advanced Boot Manager, which is located inside MBR tries to read the second part from the disk and checks its integrity. In case if it was corrupted it promts the user to boot from A: or hard disk. After that Advanced Boot Manager checks for viruses, and then compares records in MBR with its own partition table. If there were any changes, the Advanced Boot Manager copies modified records to its own partition table and advises the user to run part.exe to review them. Also see notes on installing a new OS. Then Advanced Boot Manager gives you a menu where you can select from which partition you want to boot. After you make a choice it copies the record of the selected partition to MBR table and hides the rest of the space on the disk. Advanced Boot Manager keys: ENTER - boot from the highlighted partition (you can also press 1-9) ESC - boot from the highlighted partition, but don't remember this choice for the next time. A - boot from A and put the highlighted partition in MBR H - boot from A but hide all partitions on the hard disk, except the first piece of the unused space which is larger than 63 sectors. (Good when you install a new OS). TAB - boot from the next hard drive. Editing Advanced Boot Manager Menu For each item in the menu you can specify: (see example) - Device from which you want to boot (Dev) C - current disk (on which this menu resides) D - next hard disk A - first floppy disk - Which partition should be made active on this hard disk (0 - for none) - Row in which this partition should be placed in the MBR. (see example) - Which partitions show together with the bootable partition. The choices are: Last, Previous, Next, and Last3 partitions (including the one from which you boot) - Whether this menu choice should be password protected (PP) - The name that you want to see in the menu - Keystrokes that should be placed in keyboard buffer before booting this OS. (for exaple, simulating F4 before booting Windows 95 will make Windows 95 booting the previous version of MS-DOS) If you press Alt-O you can change boot manager's options: - Boot menu title - Enable check for boot viruses - Clear screen before drawing the menu - Timeout (0 forces boot manager to stop and wait for user's input) - Default partition (overrides remembered "last selected") - Optional password for Advanced Boot Manager When password is set it protecs booting from floppy (via keys A, H) and from the second hard disk (via TAB). However, you can make a menu line which will boot from the floppy or the next hard disk, without asking the password (simply do not enable "PP" - password protected - flag).
Example of Advanced Boot Manager setup Suppose that you have two hard disks on the system: Your new 4.3Gb hard disk And old 340Mb hard disk 1 AdvBootManager 30k 1 DOS FAT-16 340Mb 2 Windows FAT-32 2600M 3 Windows NT NTFS 400M 4 Linux 400M 5 Linux swap 30M 6 DOS Extended 800M Then Advanced Boot Manager Menu could look like this: # Dev Partitions Name Keys 1 C 2/* Last Windows 95 N 2 C 2/* Last Windows 95 / Prompt Y <- "F8 6 Enter" 3 C 3/2 Last Windows NT N 4 C 4/* Next Linux N 5 C 4/* Last3 Linux (sees extended) N 6 D 6/* ---- Old MS-DOS (sees ext) N 7 D 0 ---- Old MS-DOS (sees nothing) N Note: in order to get DOS running from the second hard drive you have to do the following steps: - Install Compact or Advanced Boot Manager on the second hard drive - Go to setup screen for FAT-16 partition and set drive number to 129 - Make sure you don't have any unhidden primary FAT-16/12 partitions on the first hard drive when you boot from the second. Also note that Windows NT will be placed in row 2 in the partition table, while we don't care where will end up Windows 95 and Linux. For Windows NT it is important always to be in the same row, because it's boot.ini file has syntax like this: /controller(0)/disk(0)/partition(2)/WINNT/kernel.exe /vga /sos ... And it would not be able to find its kernel if we move it to a different row in the partition table.
Another example - preparing for installation of Windows 98 (or any other OS) - Create a bootable floppy and copy Partition Manager to it - Create and then format partition - Edit boot menu Your partitions 1 AdvBootManager 30k 2 Windows FAT-32 1600M <-- This is Windows 95 partition 3 Windows FAT-32 1200M <-- This one was just created and 4 DOS Extended 800M \ formated for Windows 98 Advanced Boot Manager Menu # Dev Partitions Name Keys 1 C 2/* Last Windows 95 N 2 C 2/* Last Windows 95 / Prompt Y <- "F8 6 Enter" 3 C 3/* Last Windows 98 N - Save this data to hard disk and to a file on the floppy - Reboot computer - In the boot manager menu select "Windows 98" and press A to boot from a "Windows 98 Setup" floppy - After installation of Windows 98 run Partition Manager to review any changes in MBR and reinstall boot manager if nesessary.
Compact Boot Manager Compact Boot Manager fits in 446 bytes and doesn't need any space on the disk beyond MBR. It is simply an IPL. When you install it you have 4 options: - Enable check for boot viruses - Prompt's time-out - Default partition (overrides remembered "last selected") - Default place to boot from if none of the partitions are active. The choices are A: and the next hard drive. Hint: if you set default partition to A then computer will always boot from A:, if to Tab - from the next hard disk, and when set to Space - then it will stop and wait for your choice.
Understanding messages of Compact Boot Manager Message Description Press ESC to skip prompt and boot OS Press SPACE to stop and wait for selection "Booting from: 1 ..." Press 1-4 to boot from corresponding partition "Booting from: _" Press A to boot from a floppy or TAB to boot from the next hard drive. Any other key will resume booting, and will remain in the buffer. For instance F4, F5, F8, ... (see hints) "Writing changes..." IPL is saving your selection into MBR. "Error!" Error reading disk or empty partition selected. "Virus in MBR!" IPL found that one of interrupt vectors doesn't point to ROM BIOS memory (see virus protection). You can press ENTER to resume booting, but it would be better to shut down the computer and run antivirus program, after booting from a clean floppy disk.
Virus protection IPL that comes with this program can detect viruses even before operating system gets into memory. This is important, because some MBR viruses cannot be detected by antivirus programs that are loaded after operating system. Virus detection is implemented by checking 29 interrupt vectors from int 0h to int 1Ch. They must point to addresses C000:0000h or higher, where ROM BIOS resides. These interrupts control all vital functions of the system, such as Timer, Video, Keyboard, and Disk. If any of the interrupts have been changed it is very likely that a virus invaded the system. In this case the IPL stops and warns user. You have a choice to continue booting with virus in memory or rebooting the system and run antivirus. See IPL messages section. However, on some systems this method of checking for virusus will produce false alarms. In this case you can disable virus detection. Another way of protection from viruses is to avoid accidental boots from the floppy drive. With this program you can do that, while still being able to boot from floppy, when you need it. To do that: 1. Install either Advanced or Compact Boot Manager that comes with this program. 2. Change boot sequence to C:,A: in the BIOS setup 3. When you need to boot from A: at the boot time press A. This trick will not only save you from viruses, but will also speed up your work. It is especially impressive if you have QEMM 8.xx together with MS-DOS or Windows 95. Set "BootFloppy:N" option in QEMM's quick boot and add "SWITCHES=/F" to your CONFIG.SYS file. Next time, when you reboot QEMM's Quick Boot will skip BIOS memory test and take you straight to the Compact Boot Manager's prompt where you will be more comfortable with pressing F4, F5, or F8 ...
Creating a new partition To create a new partition find unused record in the partition table and press INS, then select desired File System type. After you do that Partition Manager will automatically put values for cylinders, heads, and sectors. In most cases you don't need to modify those values. But if you have in mind your own partitioning scheme you can change them. When you do that, do start and end partitions on the cylinder (or head) boundaries. It is not required, but highly recommended. For example, if your hard disk has 16 heads and 63 sectors per head, you should start partition on head 0, sector 1 and end on head 15, sector 63. If you need to install several operating systems such as MS-DOS, Windows 95, or Windows NT, and you want to avoid their interference with each other you may want to hide existing partitions, while installing operating system into a new one, and unhide them later. While you are entering numbers partition may turn red. Don't worry about it until you finish. The red color of the partition means that the settings appear to be invalid or conflicting with the current disk geometry. To help you figure out what's wrong I had defined four error codes. They are shown in red color on the right when you move cursor on the invalid partition. mbr: partition overlaps MBR in the first sector of the disk or extended dos partition. range: partition have values for cylinder, head, or sector (CHS) outside of the range of disk or extended dos partition boundaries or it ends before it begins. Move cursor on the CHS fields to see the hint with allowed values. overlapped: two partition are overlapping each other. inconsistent: this message means that CHS values do not correspond to starting sector and partition size, which are also stored in the partition table. Usually this happens if partition table was damaged or BIOS disk geometry translation has changed since partition table was last modified. This error will also appear if you have value 0 for sector (sector must be at least 1). If the red color appears as soon as you started it may be because you have changed disk controller or BIOS settings or MBR was corrupted. If this is the case don't change any values unless you are absolutly sure what you are doing. Hint for the professionals: no matter how BIOS represents disk geometry the relative number of sectors and partition sizes hold. To fix the problem of inconsistency you have to switch to the LBA mode by pressing F4, note the size of the partition, change it and then change it back to the correct size. This will force the program to recalculate the values in CHS according to the current disk geometry. However, keep in mind two things: As far as I can tell DOS uses CHS values to boot and doesn't use starting sector/number of sectors fields. Instead, it uses field "sectors prior partition" and "big total number of sectors" from its boot record. If you had used OnTrack DDO or Ez-Drive you should know that they skew disk: OnTrack by 63 sectors and Ez-Drive by 1 sector. Therefore you have to reflect this change in DOS boot records.
Formatting partition You can format partitions or just check disk surface for bad sectors without destroying the data. To verify any partition press V in interactive mode or run: part -v n To format partition press F in interactive mode or run: part -f n options ... Format options depend on file system that you are formatting. Important notes on formatting DOS partitions First of all DOS cannot see newly created partition, untill you reboot computer, because it scans partition table only once. So if you created and/or formatted a new partition you have to reboot before you can use it. If the partition already mounted (you can see it as a DOS drive) and you formatted partition with different parameters you also have to reboot computer, because DOS keeps in memory old numbers, and will most certainly mess up the disk if you will try to write to it without rebooting. The other problem is disk caches. Partition Manager flushes them using SmartDrive v 4.00+ API. Most of the new cache programs, such as PC-Cache 8.0, NCACHE2, SpeedDrive support it. But if you have any other cache you should disable it before formatting DOS partitions or reboot computer after formatting. The difference in behaviour of part.exe and format.com is that part formats partitions by number in partition table and format by letter in DOS device list. Therefore before rebooting you shouldn't use programs that accesses partitions via DOS, but you can use programs that writes to partitions bypassing DOS. For example zpart, which compresses and decompresses entire partitions to and from files. Limitation: currently this program cannot format logical DOS drives from the command line - you have to go to the interactive mode.
Important issues on installation of a new OS Windows 95 and some other operating systems upon installation replace your current IPL with their own code. If you have Compact or Advanced boot managers installed on your hard drive you would not see them at the next boot. I have worked on this issue. It should not lead to the loss of data, at least with Windows 95. In the worst case you just would have to run part.exe and reinstall boot manager. But to ensure that nothing will be lost do the following steps before installing new OS: - Create a bootable floppy and copy Partition Manager on it. - Run Partition Manager and create partition for the new OS. - If possible format it using Partition Manager. - In Advanced Boot Manager edit boot menu (see example) - Save Partition Manager's data to the floppy. - Reboot computer and install a new OS If MBR will be modified by OS installer review the changes and reinstall boot manager.
Supported file systems Unused partition Classical MS-DOS file systems Windows 95 FAT-32 file system Extended DOS partition Making logical drives bootable
Unused partition This simply indicates that entry in partition table is available. It doesn't tell anything about free space on disk. You have to figure out that yourself. However if you specify starting and ending locations of partition with type "Unused" Partition Manager will let you format and verify the disk space. Format takes two options: "/destructive" or "/clean". First one performes low level disk format, second one fills disk space with zeros.
Classical MS-DOS file systems 0x01, "DOS FAT-12" 0x04, "DOS FAT-16 (under 32M)" 0x06, "BIGDOS FAT-16 (over 32M)" All file systems have the same structure: [Boot Sector] [First copy of FAT] [Second copy of FAT] [Root Directory] [Cluster 2] [Cluster 3] [Cluster 4] ... Boot sector, FATs, Root Directory, and clusters have fixed sizes, which you can set only when you are formatting the disk. Space for all subdirectories and files is allocated by clusters. If cluster size is 8 sectors = 4,096 bytes, when you create file with size of 1 byte it will get entire 4,096 bytes cluster. There is an entry in FAT (File Allocation Table) for each cluster, which tells if cluster is free, allocated, or damaged. Therefore size of the FAT determines maximum number of clusters. FAT-12 file system is limited to 4084 clusters. It is used on the floppy disks, but you can also use it on a small hard disk partition. FAT-16 was used on early hard disks. Original version could have up to 65,000 clusters on partitions up to 32M. BIGDOS FAT-16 which was released with DOS 3.31 doesn't have 32M limitation and can be as large as 2G. For backward compartibility all DOS versions later than 3.31 will accept both FAT-12 and FAT-16 file systems in the BIGDOS partition. This program includes format utility which formats all three file system types. It has the following options: part -f n [/quick | /destructive] [/l:volume_label] [/c:sect_per_cluster] [/x:max_num_sect | /x:disk] If you specify "quick" option, the program will assume that your hard disk doesn't have any bad sectors. You can verify disk once, and if it doesn't have bad sectors you can then use quick format. If you don't specify cluster size it will be selected automatically depending on partition size from 4 sectors and up. Here is the table for BIGDOS FAT-16 file system: Cluster size Maximum partition size 1 sector 512 bytes 32M * 2 sectors 1,024 bytes 64M recommended * 4 sectors 2,048 bytes 128M cluster sizes * 8 sectors 4,096 bytes 256M are marked * 16 sectors 8,192 bytes 512M with '*' * 32 sectors 16,384 bytes 1G * 64 sectors 32,768 bytes 2G 128 sectors 65,536 bytes 4G Although you can format disk with all those cluster sizes it's not recomended to use very small or very large values. Many programs have weird bugs with that. For example, SCANDISK will freeze if cluster size is 128, while Norton Disk Doctor seems to work without problems. By specifying max_num_sect parameter you can reserve space in FAT for the future expansion of the partition. If you type "/x:disk" (exactly as it is written) format will make FATs large enough so that you can expand you partition to entire disk. You can make FAT partition smaller (split them). To do that run some disk defragmentation utility (like DEFRAG.EXE). Then go to setup screen inside part.exe. One of the lines will show the minimum partition size, based on the last cluster occupied by data. The value should be equal to sum of the file and directory sizes on your disk. If it is greater it means, that some hidden files were not moved by the defragmentation utility. You have to find those files (for example Norton Speed Disk will show their names), remove system and hidden attributes and run disk defragmenter again. But be careful with moving them, because some programs may use absolute file locations for their illigal installation checks.
Windows 95 FAT-32 file systems 0x0B, "Windows 95 FAT-32" This file system was designed to support disks larger than 2G, which was the limit for FAT-16 file system. FAT-32 partition can be as large as 2T (2,048G). It has the following structure: [Boot Record (3 sectors)] [Backup Copy of Boot Record] [First copy of FAT] [Second copy of FAT] [Cluster 2] [Cluster 3] [Cluster 4] ... Root directory on FAT-32 treated as an ordinary directory, and can be located anywhere on the disk and doesn't have predefined fixed size (unlike FAT-16). Options for formatting FAT-32 file system are similar to FAT-16 options: part -f n [/quick | /destructive] [/l:volume_label] [/c:sect_per_cluster] [/x:max_num_sect | /x:disk] Strategy for resizing FAT-32 partition is also similar to one for FAT-16: - Run defragmenter utility on the FAT-32 partition - Change partition size in the partition table - Enter setup screen and make same changes there (make sure they are valid - otherwise they will turn red) - Reboot computer and run scandisk to check that everything is ok and also to reset amount of free space.
Extended DOS partition Partiton table has space for only four records. To have more than four partitions DOS uses Extended DOS partition scheme. This scheme allows you to have as much as 23 DOS volumes on one physical drive. Unfortunately, native DOS's program FDISK imposes another limitation that you cannot have more than one primary (bootable) MS-DOS partition on the hard disk. The truth is you CAN have more than one. The problem is that MS-DOS's FDISK refuses to create second one for you. If you run FDISK it will create one primary partition and then will mark the rest of the space as an Extended partition. The first sector of the Extended partition is called EMBR (Extended MBR). It has the same structure as MBR. Inside of each Extended partition you can have one FAT (or NTFS) partition, called logical drive, and another Extended partition. For some unknown reason relative sectors of inner extended partitions are calculated from the beginning of the outermost partition, while relative sectors of FAT partitions are from the beginning of the enclosing extended partition. Here is an example: HD 520 Mb --------------------------------------------------- Primary FAT-16 120Mb [ C: 120Mb ] Extended DOS 300Mb ----------------------------- FAT-16 100Mb [ D: 100Mb ] ExtDOS 200Mb --------------- FAT-16 200Mb [ E: 200Mb ] --------------- ----------------------------- Linux 100Mb [ / 100Mb ] --------------------------------------------------- Note that the order of partitions on the disk also matters. FAT partition must go first. And the extended partition must follow. Hint: in the Partition Manager you can use PgUp and PgDn to jump between EMBR levels. You cannot boot from extended partition, nor from any logical drive inside of it. If you try it, the system would simply hang, because its boot record unlike other file systems doesn't have any loader code. It has only zeros. You can install a "non bootable" dummy boot record, which instead of crashing will display a message: Extended DOS partition is not bootable. Press any key to reboot... Making logical drives bootable As I mentioned before, you cannot boot from Extended partition or from any logical drive contained in it. But what if you need? The solution is simple. All you have to do is to move the record that describs logical drive from the EMBR to the primary MBR, and adjust size of the Extended partition. Then you have to set the correct number of "sectors prior to partition" in the DOS boot sector, whose value is used to load system files. And finally you have to run sys.com to install system files on disk. Lets see what we can do with our example. Variant 1. Notice that size of the extended partition was changed and second extended partition is gone. HD 520 Mb --------------------------------------------------- Primary FAT-16 120Mb [ C: 120Mb ] Extended DOS 100Mb ----------------------------- FAT-16 100Mb [ D: 100Mb ] ----------------------------- Primary FAT-16 200Mb [ E: 200Mb ] Linux 100Mb [ / 100Mb ] --------------------------------------------------- Variant 2. Here we just moved both records from extended partition to the MBR. HD 520 Mb --------------------------------------------------- Primary FAT-16 120Mb [ C: 120Mb ] Primary FAT-16 100Mb [ D: 100Mb ] Extended DOS 200Mb ----------------------------- FAT-16 200Mb [ E: 200Mb ] ----------------------------- Linux 100Mb [ / 100Mb ] --------------------------------------------------- Variant 3. HD 520 Mb --------------------------------------------------- Primary FAT-16 120Mb [ C: 120Mb ] Primary FAT-16 100Mb [ D: 100Mb ] Primary FAT-16 200Mb [ E: 200Mb ] Linux 100Mb [ / 100Mb ] ---------------------------------------------------
Command line options Usage: part [-q] [-d disk] [-command ...] part - Interactive mode part -i - Print IDE disk info part -p - Print partition table part -p -r - Print info recursively part -a n - Activate n-th partition part -v n - Verify n-th partition part -f n ... - Format n-th partition part -s file - Save MBR to file part -l file - Load MBR from file part -c file - Compare MBR with file part -Reboot - Reboot computer The program returns exit code 0 if there was no errors and/or compared objects had no differences (1 is returned otherwise).
Additional information and help for Partition Manager Partition Manager Home Page Partitioning Primer Partition Manager FAQ (always up to date) Links to partitioning and bootstrap related materials
Contacting author and copyrights This program is a FreeWare. You can freely distibute it. Source codes are available for download from my home page. When you send questions, please, include: 1. Print out of all partitions (part -p -r > some_file). 2. Information about operating systems installed on your disk. 3. List of all things that you did before running into troubles. Also visit my web site to read additional help and check whether the next version of this program already solves your problem. French interface: Patrick Robbe, probbe@mail.dotcom.fr German interface: Peter H. Dillinger, dilli@rumms.uni-mannheim.de Spanish interface: Alberto Cajigas Jr., BeLion007@aol.com Swedish interface: Dan Olav Mikael Hultgren, mikhu265@student.liu.se Mikhail Ranish ranish@intercom.com Home page: http://www.intercom.com/~ranish Or http://www.ml.brooklyn.cuny.edu/~mranish