Frequently Asked Questions

Linux + Windows HOWTO
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# A.1. Frequently Asked Questions

A.1.1. After running fips, why does Windows report that I still have only one partition?
A.1.2. Why does my tool report an error that physical length does not match the logical length of the partition?
A.1.3. How do I know what version of Windows I have?
A.1.4. How do I know what version of linux kernel I have?
A.1.5. How do I know what version of linux distribution I have?
A.1.6. If I make a mistake can I start over?
A.1.7. How large should my swap partition be?
A.1.8. Should I add package xxx?

A.1.1. After running fips, why does Windows report that I still have only one partition?

Windows 98 does not recognize the effect of fips-0.9e. fips-2.0 has successfully been used to split a Windows98 partition. According to an unreliable source, Windows 98 reads partition data from the first 512 bytes of the partition itself and considers this more reliable data than the partition table.

A.1.2. Why does my tool report an error that physical length does not match the logical length of the partition?

This means that the partition table is inconsistent, and may be inaccurate. Modifying a disk with an inaccurate partition table usually requires an expert to reduce the almost certain chance of data loss.

The severity of this message is dependent on the size of the disk. Due to historical limitations, most (but not all) computer BIOSs only support disks with less than 1024 cylinders. Booting the operating system depends on the bios, therefore (on such systems), the entire operating system must fit within this 1024 cylinders.. For the same historical reasons, the partition table format only supports reporting disk sizes of 1024 or less cylinders. Many disks today have more than 1024 physical cylinders but by convention the partition table records exactly 1024 cylinders. The operating system still needs to know where the actual partitions begin an end beyond the first 1024 cylinders and this is recorded in the partition table.

A large disk with more than 1024 cylinders will have a logical size (sum of partition sizes) that exceeds 1024 and matches the actual size, though the partition table reports a physical size of exactly 1024 cylinders. In the case of a large disk, this message is essentially useless.

A.1.3. How do I know what version of Windows I have?

One or more of the following should tell you what version of Windows you have.

- C:\>ver

- {My Compuer} [Properties] [General]

- [Start] [Run...] Open: command [OK]

- [Start\Run...] Open: ver [OK]

- [Start\Run...] Open: cmd ver [OK]

A.1.4. How do I know what version of linux kernel I have?

bash> uname -a

A.1.5. How do I know what version of linux distribution I have?

The question may have no meaningful answer. Since unix dialects (e.g. linux) use many interchangeable parts, it makes little difference to this HOWTO what distribution you have. The applications loaded on most linux hosts varies with time and the tastes of the owner, so that they seldom match any distribution for more than a very brief period.

Most distributions are loosely classed by the package manager that they use.

- pkgtool - slackware

- rpm - RedHat

bash> uname -a

A.1.6. If I make a mistake can I start over?

In general, no. For this reason, meticuluous care is required, especially at certain stages. Some of the operations are idempotent. An idempotent operation is one which either fails and has no effect, or succeeds and has no effect after its first success. Some of the operations are reversible. A reversible operation has an inverse operation so that you can return things to what they were and start over.

Formatting is especially dangerous because it is neither idempotent nor reversible. If formatting succeeds, the original data is lost. If formatting fails, the original data is probably lost (since indices are usually destroyed early).

Table A-1. Distributions

Operation | Idempoten | Reversible | Inverse Operation | Caveat
--- | --- | --- | --- | ---
Backup | Yes | Yes | Destroy the backup | Try reading the backup lest it be corrupt
Catalog | Yes | Yes | Destroy the catalog | Record too many details since only 1-10% will ever be used, though it is hard to predict which 1-10%.
Attach | No | Yes | Disattach the devices | Use electrostatic protection and personal safety procedures lest the delicate components or yuurself be damaged physically.
Compact | Yes | No |  | Repair filesystem errors before compacting, since recovery will probably be impossible after compacting.
Repartition | Yes | Yes | Record the starting table. Reenter the recorded starting table | Carefully check the partitioning before using the computer, since applications will believe the partition table and may destroy files. A small error in partition borders or lengths may cause infrequent disk errors that are not seen for months, but can become very time-consuming.
Format | No | No |  | All data in the partition is destroyed so make sure that there is no useful information in the partition and/or that the data is in a good backup.
Initial Program Load | Yes | Yes | Format the partition | Carefully record, test, and expect to change the configuration of linux as your understanding, needs, and desires change. As you use your computer, you can expect to quickly find that you wish you'd made different configuration decisions. Most linux distributions allow easy reconfiguration of a running system.
Boot Manager | Yes | No |  | Windows installation overwrites the boot manager with one that loads Windows automatically. If you isntall Windows+linux, you must installl Windows first.
Mount | Yes | Yes | Unmount | Care with permissions is needed to prevent undesired use of the computer (e.g. openning your telephone to anyone on your cable modem network may tend to increase your phone bills.).

A.1.7. How large should my swap partition be?

Swap partition size (or even its existence) is a hotly debated issue beyond the scope of this HOWTO. Many books on performanc tuning provide guidelines on swap partition size and how to recognize a need to expand or shrink it. At press time, the author recommends 64M as a safe size.

A.1.8. Should I add package xxx?

A reader of this HOWTO presumably wants to benefit from the strengths of both Windows and linux, and suffer the shortcomings of neither.

Most linux distributions allow you to cleanly remove any package. unix dialects support permissions so that each package gets a well defined share of the computer and this share can be identified and taken back in its entirety. unix dialects support symbolic links so that the package can appear to be in a convenient place without actually occupying space from the convenient place. The distributions that do not support easy removal are usually tiny specialized distributions like tomsrtbt. The risk that an unwanted package will plague your linux indefinitely is small since you can remove it at any time.

Most Windows packages can never be uninstalled cleanly under Windows, as they usually leave dll updates and registry entries. It is therefore important to add packages only when you are sure that you need them, since your only way of removing them may be to reinstall Windows and every package that you want.

Sharing a machine between Windows and linux, means that linux can aid clean removal of packages from Windows. Since it only identifies but does not predict, linux cannot insure clean removal. Since linux find resolves to the second rather than Windows find to the day, it can much more accurately identify what was changed.

1. Record the date and time before you install a package to Windows.

2. Install the package.

3. Record the date and time after you install the package.

4. Under linux, use touch to create a file timestamped at the start of installation.

5. Under linux, use touch to create a file timestamped at the end of installation.

6. Under linux, use find to identify every Windows file and folder that was altered during installation.

7. Store the list of altered files and folders to identify what has to be removed or restored.

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