21 replies to this topic

[WreckWench]

I've heard it mentioned many times how people partition their MAC hard drive to run a copy of say xp/windows on their computer alongside the MAC OS.

I've heard people say they can 'mirror' a website or data into a fully standalone separate area of their computer as a backup.

What does this all really mean and when does it really make sense? If it serves a purpose in your own application/situation how do you do it and where? On the same hard drive? A standalone hard drive?

[peterbj7]

I do it on my Windows laptop. One partition runs Windows 7, another has Windows XP for those applications that won't run under 7. Don't know how to do it with a Mac though, yet.

[Scubatooth]

running a windows operating system on a MAC computer requires the use of a virtual machine program (parralels is one option for mac) for which then you can install a windows OS. Its a little different then mirrorring data on a harddrive or between harddrives.

[WreckWench]

Ok now is a great time to spell it out for the

I think it has some great uses and applications but as you can see I'm a bit confused on how it all works.

So Peter how did you do it on your computer since your application is not only straightforward but I'm sure something MANY members have run into... how to run applications using XP when your computer runs win7.

[peterbj7]

My machine ran Vista when new. A total abomination of an operating system. I had intended to load XP instead, but found what to me then were insuperable difficulties and I gave up and put up with Vista. When the machine was around 18 months old the hard drive failed - pretty normal at that age. I replaced it with a new one and had to load a new operating system, because I had no means of reloading Vista (I was given nothing by Toshiba to help with that). After considering my options I had Win 7 installed by the local professionals (so they would have the problem of finding all the necessary device drivers), and that worked quite well. As an operating system it's easily Microsoft's best yet, not that that's saying a great deal, but I still greatly dislike many of the arbitrary and unnecessary changes they've made to the user interface, apparently just because they can. These changes actually go way beyond trivial reactions to key strokes or mouse clicks, and what I dislike about them is that I know that most if not all did not need to be made. Microsoft are deliberately trying to frustrate the computing public, probably in the belief that they'll rush out and buy new software (and hardware to run it on). Well, not this one. I accepted XP as an honest if fairly incompetent attempt to create a radically improved operating system. Vista showed me what dishonest cowboys they really are, and that has only been partially retrieved by 7.

Anyway, I discovered pretty early on that the XP programs I had and liked that wouldn't run on Vista wouldn't run on 7 either. So I tried my version of Partition Magic to split the existing single partition into two. That didn't work because my version of PM doesn't run on 7, and in fact the product has been totally discontinued for 7 (I have no idea why). So I searched the internet to find an alternative. I discovered EASEUS, a free partitioning program that runs on both 7 and XP (and probably Vista as well, though I didn't try it). I used it to split the 7 partition, a very simple job that is self-explanatory when you try it. I created a new partition that would be big enough to load XP and a few other programs, but no bigger than that. I then loaded XP into that partition. I had some problems finding device drivers but I managed it.

So now my system is "dual boot". When I boot it (not when I restart from sleep) I am offered a choice of operating system to run. Whichever one I choose then takes over the machine until I reboot, and the other OS is invisible to me. Although there are aspects to 7 that I considerably dislike and don't think I will ever truly accept, I always choose to run 7 unless there is a positive reason to run XP. I have three reasons - (1) under 7 the boot, sleep, awake and shut down processes are vastly quicker than they are under XP. When the machine ran Vista a boot took just over seven minutes, an appalling amount of time when you're waiting, especially since the OS was so unstable I normally had to reboot several times a day. Under Win7 these processes take just a few seconds, and I rarely (but not never) have to reboot because 7 has thrown a wobbly. XP takes an intermediate amount of time, three-four minutes for a boot.

My second reason is that for my particular hardware the driver available for wireless reception under 7 is much more sensitive than the one available under XP. I often find it quite hard to connect when I'm on XP, though on 7 it's easy. It was easy with Vista as well, which is probably explained by the hardware/driver having been designed for Vista/7 and the XP driver being an old one (it is) that is far from optimised.

A third reason is that although I can see no logical reason for it, the same email package (Windows Mail) run under the two different OSs seems to affect the email database differently, and erratically I find the database corrupted when I change OSs. The safest thing to do is stick to the one OS for email, and as internet connectivity is easier under 7 that's the one I choose. I can't wait though to get away from the MS product and onto a better designed one like Thunderbird.

The two partitions show themselves as different drive letters, and though they're both physically on the same hard disk, they appear logically to be different disks. I can read both partitions as data storage whichever OS I'm using. The new drive I installed was 500gb, so I have plenty of room for the different partitions. I don't keep permanent data on the internal hard disk anyway, so it only has to be big enough for the data I'm currently using and I have a lot of unused space.

Edited by peterbj7, 09 January 2011 - 06:47 PM.

[drifter]

I haven't worked with Mac's, so someone will have to post if they can do the following in the same way as a Windows PC.

Partitioning: This is essentially splitting your hard drive into separate "virtual drives" For example, my computer has one physical hard disk, but when you look under "my computer" it has a C drive, a D drive and an E drive listed. This is because I've created 3 separate partitions. C is where Windows is at, D is data and files, E contains the Linux operating system. There is free software you can download to do this. There are some restrictions on which operating systems can run on which hardware. I use it because I've gotten addicted to Windows yet Linux is a better system for a lot of my work.
(Edit)...when you try to install a second operating system on a computer, it will typically give you the option during the installation to set up a separate partition on which to install the new operating system.

Mirroring: This is typically used for computers that contain ESSENTIAL data (a web site or a database). When I've encountered it(only a couple of times), there is one physical disk that will be used as the 'primary' drive for the website and another disk that is a backup. Any updates that occur on the primary drive occur at the same time on the backup (it is a mirror image of the primary). This gives you a complete, up to date, and ready to use, backup if the primary drive should fail.

There are several ways you can accomplish this. What you want to remember is the idea is to backup so there are certain requirements that you want the two disks to have:
1) they shouldn't be partitions on the same physical drive
2) they should be connected continuously (they can be in the same computer box or around the world but hooked up to the internet at all times) so that updates can be mirrored from the primary to the backup as they occur.
3) they should be similar in size so you don't run out of backup space

[drbill]

I used to partition my hard drives into Windows and Linux partitions so I could boot to either OS depending on what software I wanted to use. This is not much different than partitioning a Mac to run its OS (Linux based) and Windoze.

I don't mirror my drives.. I make copies of them onto other drives which are generally disconnected from the system. Many of the files I use are static once a project is completed, so I am not so concerned with creating duplicate copies as I work on a new project, only ensuring I have a good (actually several) backup copy of completed work. I do back up daily (or more frequently) on the specific projects I'm actually working on at the time.

Back when I kept separate computers at my lab in Santa Barbara and my home on Catalina, I used a single removable hard drive (a removable drive carriage back in the days when external drives were rare and costly) to back up data from my present location and transfer it to the other computer when I changed locations. It worked great and kept copies in two geographically remote areas. Now that I work mainly with video (HUGE data sets), this is next to impossible (at least on my budget).

[Landlocked Dive Nut]

I have my file server at work set up with a mirror drive. If the primary drive fails, it's set up to automatically switch to use the mirror drive, and we have no interruption in functionality. This is very important, as ALL of our stores hit our server for the real-time Point of Sale software.

But, I paid someone to set it up for me, Kamala. I wanted to make sure it was done right!

Separate drives for backup of data is done for completely different reasons in most cases.

[shadragon]

Really don't mean to be picky, but you have to be very careful with the terminology as it connotes different things.

Partitioning: This is essentially splitting your hard drive into separate "virtual drives"

Sorry, not correct. This should read "This is essentially splitting your hard drive into separate logical drives".

Partitioning creates independent disks which can be formatted and operate independent of each other, if desired. One can be formatted NTFS, one can be FAT32, one can me MAC, etc. This is used for dual / triple boot situations or you can segment a hard drive for organizational purposes under a single OS. One for games, one for documents, one for your home business, etc. with all visible to the host OS.

A Virtual drive is a disk that looks to the OS that it is a regular drive partition, but it cannot be directly accessed unless you use disk emulation software as a middle step. Alcohol 120% uses virtual CD-ROM and DVD drives and you can mount an image of a CD or DVD from an image without actually using a real CD or DVD, for example. Virtual drives do not exist natively to hardware and are not accessible without an intermediate step.

Mirroring requires two identically sized and physically separate disks with a RAID (Redundant Array of Independent Disks) controller to send a copy of any written information to both disks simultaneously. There is no primary or secondary, they compromise the same physical volume at all times. So two 20 GB hard drives appear to be a single 20GB hard disk. If one drive fails, you can unplug it, replace it with another and rebuild the "mirror" from the good one. This is also called RAID 1 and is the fastest and most common RAID level. RAID 1 HD should be in the same physical machine or performance will suffer and in case of power loss, information corruption is almost certain.

[drifter]

Doh,I should have said logical instead of virtual. Good catch Simon!

As for mirroring, doesn't it depend on what you're wanting to do? If it's an entire hard disk on a computer you possess then Raid 1 is a good way to back things up. If it's website or a database, you might not use the Raid 1 definition, correct? I'm almost positive when we had mirrored databases they weren't on identical hard disks.

Kamala, do you have a specific goal or are you just trying to gain additional information?

Scott

[WreckWench]

Hey Drifter...great to see you again and of course to have your professional insight! BONUS!!!

Mostly I am learning..BUT...

I'd like to have a mirror system set up much like Tammy has for her work if I have a failure. I am interested in partitioning to again see if there are any applications for use for SD.

And I am REALLY learning a lot! Thank you guys! kamala

[shadragon]

Doh,I should have said logical instead of virtual. Good catch Simon!

As for mirroring, doesn't it depend on what you're wanting to do? If it's an entire hard disk on a computer you possess then Raid 1 is a good way to back things up. If it's website or a database, you might not use the Raid 1 definition, correct? I'm almost positive when we had mirrored databases they weren't on identical hard disks.

RAID1 is mirroring; the terms are interchangable. Like a mirror, what you see on one side is reflected identically on the other. There are many ways to protect a DB like clusters, but they are typically beyond the reach of small businesses due to cost and technical complexity. Mirroring can go from a logical drive or complete HD. Most motherboards have onboard RAID1 controllers as a standard feature today.

RAID1 adds a backup layer and is fast. Typically the fastest redundant solution (performance wise) and best for home users as it is cheap and easy to fix when a drive fails. You can have RAID1 on different physical hard drives, BUT the partitions have to be the same physical size. Ideally, the HD should be the same model and speed. If you have mirrored a 20GB 15000 RPM HD and a 20GB 5400 RPM HD, you are A) slowing everything down, B) asking for issues.

RAID5 spreads data across multiple disks and can create a huge logical drive, but it can only survive one disk failure as well and is a lot slower . You need a dedicated RAID5 disk controller and many HD (minimum of 3). You would not want to use it for high intensity read / write DB operations as it takes time to write across multiple drives. If you lose two disks In RAID5 you are screwed. Want to see an IT worker sweat? Watch him/her during an RAID 5 array rebuild after replacing a single bad HD.

One word of warning. There is an approach called JBOD (Just a Bunch Of Disks) where you can chain several HD together to make a large logical drive. So you can take a 20GB + 40GB + 72 GB and end up with a logical disk of 132GB total size. Beware. If you lose any one of those disks, the total info is probably not recoverable without forensic level efforts. ($10K cost) and even then you may be SOL. If you find yourself looking at JBOD, just buy a larger HD.

The best backup strategy is a layered approach using multiple methods. A combination of disk mirroring, disk / file backup on another drive or server and long term backups on DVD or tape. One other feature available on recent Microsoft OS's is called Volume Shadow Copy which will save previous versions of files letting you go back in time. In our company, we use all those methods (and a few more).

For free backup software look for Karens Replicator on Google. Nice automated package for backups. For the more adventurous, you can write XCOPY bat files or use ROBOCOPY if you have a more recent Microsoft OS. Just set them to go off as a scheduled task for hands free operation. DFS is also a built in component of windows server OS and is a good way to backup files automatically (as they change) if you have average technical skills.

For those on a budget who want to buy commercial backup software ACRONIS and SYMANTEC have reasonable backup solutions. I inherited Arcserve when I started my job in my current business and do not recommend that.

[peterbj7]

I've tried all sorts over the years, and for me this solution works best. I back up maybe once a week, though that could of course be more frequent. I back up from my laptop's internal drive to one external hard drive. When that is complete I back up from my laptop to a second external hard drive. So that if anything goes seriously wrong during one of those operations I still have a pristine HD. I only back up data, not programs or the system. Independently, shortly after a machine software rebuild (which I do every few months) I take an image of the system and store that on yet another external HD.

This system isn't perfect and it means that in the event of a crash I will have some work to do and will probably lose some data that hasn't yet been backed up. But I keep that to a minimum by retaining input data on its original media until after a back-up.

The software I use to take a system image is usually Norton Ghost 2003. Under XP Professional I used to use the in-built facility, but that (like so much that is useful) was dropped by MS when Vista came out.

The software I use for routine differential back ups is Beyond Compare, an extremely useful and powerful semi-free utility that compares one directory structure with another and can synchronise them.

[Landlocked Dive Nut]

I almost forgot about XCOPY!! I wrote a bat file many years ago to automatically back up MY DOCUMENT files from my work PC to a password-protected area on the server, and it's been working great for years. I don't even have to think about it anymore. It copies my PC sensitive files to a private area on the server every night, replacing previous versions of files. You could have it copy to any type of drive, including a removable drive.

[drbill]

XCOPY is what I used to use to transfer all data files newer than a certain date from the data drive on my computer at the lab to the removeable drive I carried back to Catalina. I then used XCOPY to copy the same files to the data drive on my home computer. Worked like a charm.

While we're talking backup methods... why isn't there a Laplink like capability built into Microsoft's OSes so you can only copy files that are newer onto a backup drive. I loved Laplink in the days of DOS. I could use the split screen to log onto the same directory on my primary data drive and on my backup drive and tell it to only overwrite files with an older time/date stamp. Maybe XP has that capability and I just haven't found it? I use Windows Explorer and it is terribly tedious (the way I use it at least) because it shows me the two time/date stamps and asks if I want to overwrite each file when it would be far more beneficial if it recognized that files with the same time/date stamp could be skipped in the process. Maybe it can do that and I just don't know how?