how2perf04.htm
Performance: My backups take a long time and a lot of diskettes
Caveat: Identifying performance issues on a computer and/or network is a very fickle and tricky thing to attempt because there are a virtual limitless number of issues that can affect performance in general. The ideas presented here are generic in their scope but may offer a glimpse into a possible solution at your facility and at least a direction you may follow to solve a problem.
Let's get a few things cleared up right away, before we go any further:
- Having a good, recent backup of your data is critically important.
- Making a backup regularly is critically important.
- Storing the most recent backup in a safe place is critically important.
- Having multiple sets of recent backups is critically important.
If you are not in agreement with all four of the above, click the "Skip this boring topic now" link below and don't bother reading this. Then call your insurance agent and purchase a healthy business interruption insurance policy because if the time comes when you can't get your system back in operation, you'll spend an awful lot of money trying to put things back in order. Your call.
If you're still with me, I'll try my best to offer some workable guidelines. First, a little overview.
The concept of making a backup is to create a copy of important data at a specific date and time and being able to remove the copy for safe storage in another place in the event a disasters occurs to the main computer. But to be able to remove the copy, it means that some sort of portable media be used because it's not practical to use a physical duplicate of the actual computer as a backup.
Luckily, there are many portable, removable types of media available. Let's talk about some of them as well as a couple methods that aren't removable .
Diskette Media: It used to be that the ubiquitous diskette was the most popular medium for making backups. They were cheap, compact, easily transportable and very convenient to use. However, the ability to store large amounts of data on diskettes that can hold only 1.44mb each required that many diskettes were necessary which then required that large files "spanned" multiple diskettes, i.e. diskette #5 might have the first part of a large file, diskette #6 the next part, diskette #7 the next part and diskette #8 the last part. To recover the whole data file from the diskettes, it meant that diskettes # 5, 6, 7, and 8 had to be used in the right order. What's more, if only one of those four diskettes became damaged in some way, it completely prevented recovering the whole data file because data files must be contiguous -- they can't have "holes" in them. Today, data files are larger than ever because we're keeping more and more detailed data. Therefore, the major drawbacks in using diskettes are (1) their small capacity per diskette requires that many of them be used and (2), the possibility that only one of a large set of diskettes cannot be recovered reduces the amount of security of the entire backup. Conclusion: if your backup requires more than three diskettes, using diskette media is not a good, safe choice.
ZIP disks: The ZIP drive from the Iomega company has been a popular option for about ten years, and ZIP media is available in 100mb, 250mb, 750mb, and 1gb sizes and generally costs less than $10 per disk. It is generally quite speedy and provides a rather inexpensive way of making backups. Another wonderful benefit is that not only is the media portable, the drive itself can be. For example, an external ZIP drive that uses the USB interface can be used by any user whose computer has an USB port.
CD-R and CD/RW: a typical compact disk (CD) can hold 700mb worth of data. CD-R type disks are generally for single, one-time use (they cannot be reused) while CD/RW is generally reusable for a few hundred times. CD media is generally quite inexpensive and is a good solution for applications backups but not necessarily for file servers because of the limited 700mb capacity. One of the really nice benefits is that the cost is so low (about 15 cents each) that having multiple backups of an entire directory of data (as long as it's less than 700mb) makes making archival daily backups truly affordable -- about $1 for an entire week (1 disk per day) . Generally, making a CD backup is a manual process, but some software programs exist that can automate the process at a predetermined time of the day. And while CD media is quickly losing ground to DVD media as the latter has greater storage capacity, the CD still has excellent application at the individual computer as a viable backup medium.
DVD-R, DVD+R and DVD/RW: While very similar in physical form to CD media, with a capacity of 4.7gb, DVD disks can hold nearly seven times more data than a typical CD, making DVD backups more applicable to some file servers and certainly to those who need to back up whole directories that are larger than what a CD disk can hold. DVD-R and DVD+R represent two different methods for storing the data on the CD (the actual media is physically different, too) and both these types are for one-time use only and cannot be reused. DVD/RW media is erasable and reusable. Relatively new to the scene are "dual layer" DVDs, which essentially double the capacity from 4.7 to 9.4gb, and "blue ray" media are on the horizon which offer capacities up to 20gb or more. Even though DVD is a product in flux, it's a worthwhile consideration if your needs exceed the CD's maximum capacity of 700mb. The media itself is still inexpensive (about 25 cents per DVD disk), making it easy to store multiple, archival data backups made on different dates.
USB Flash Memory Stick/USB Flash drive: These wonderfully convenient and inexpensive little electronic gizmos come in multiple sizes, shapes and capacities, but it's really only practical as a backup media when the capacity of the memory stick is at least 1gb (about 30% larger than a CD's capacity). At $10-$70 each they're more expensive than other media types, but one benefit is that they're completely reusable, easily fit in your pocket and appear to the computer just like a disk drive making them very convenient to use. Their small size is also a drawback: they're easy to lose or forget having been put into a pocket; if you sit on it and break it or run it through the washing machine they can become irreparably damaged, making the data on them permanently lost. They're also not as speedy as you might think and copying a whole folder to a memory stick may require ten or more minutes while copying the same folder to a DVD or CD may take only a minute or two. But for overall convenience, if the computer being backed up has a USB port, the USB memory stick gets an A+.
Tape: Many tape backup drives are available and they're popular because tape cartridges generally can hold much more data than most any other type of removable media -- on the order of tens to hundreds of gigabytes. Tape backup systems are even available with capacities in terabytes, or thousands of gigabytes. However, tape cartridges are a bit delicate and are easily damaged if mishandled, making the data on them unrecoverable. Also, recovering a specific single file from a high-capacity tape can be a time-consuming and arduous process. Nevertheless, tape drives continue to be popular solutions for large file servers and backup software can be used to automate the backup during the middle of the night. One of the benefits of a central, server-based tape backup is the ability to back up not only the server's data, but everything on all the other computers on the network, too. Tape media is generally the most expensive type of removable media available and a set tapes (one for every day of a single month) can easily cost $2,000, so keeping permanent archival backups can be quite expensive.
Disk Mirroring: This is a non-removable method but it worth mentioning here. It's available only on the Windows Server operating system, and it works by having two identical hard disks inside the computer. Windows Server provides services that when you store a data file to the server, it is actually written to BOTH hard disks simultaneously. The end result is that the server has a pair of hard disks that are identical. Should one of the hard disks crash, the other hard disk can simply be activated and you're back up and running almost immediately. This sounds expensive, but it's really not -- a 500gb hard disk these days costs only a hundred dollars, and Windows Server software isn't terribly expensive, either. As stated earlier, disk mirroring requires that the hard disks be installed inside the computer and are therefore, not removable or portable. Nevertheless, using disk mirroring on a server is a good and relatively inexpensive method to increase your server's data security. We have personal experience with the benefits of disk mirroring in our office. A couple years ago our server's primary hard disk crashed. We powered the server off, activated the mirrored disk, installed a new "blank" hard disk in place of the dead one and powered up the server again. When the server came online a minute or so later it automatically started mirroring itself again to the new blank hard disk we'd installed. Total down time was about fifteen minutes. If you have a Windows Server, you should at least be utilizing this built-in tool.
RAID: This is another non-removable server-based method that's somewhat similar to disk mirroring. The acronym RAID stands for "redundant array of inexpensive disks." A RAID setup includes 3, 4 or 5 identical hard disks installed inside the server, and the RAID server software and controller "stripes" the data across all five of the disks so that if any one of the hard disks crashes, the remaining hard disks compensate and fill in for the dead one. Additionally, the RAID controller hardware allows the hard disks to be "hot-swappable," meaning that the server can remain running (you don't have to power it off) while an individual hard disk is replaced, and once the new hard disk is running again, the RAID software automatically recognizes it and restripes the appropriate data to it. RAID virtually eliminates any sort of server "down time" (as long as the electrical power isn't out, of course) and for mission-critical systems that can never be "down," it's absolutely the way to go. While it's not a "backup" system, RAID is the ultimate method of data security on a network server which the business can never afford to power down for maintenance.
Okay, now that you're armed with some basic information about backup systems, let's talk about the initial concern: "my backups take a long time and a lot of diskettes." The essential problem can be summed up and restated as follows: diskette media is not appropriate for the large amount of data you are trying to back up, and you should change to a higher capacity medium..
This may involve purchasing and installing a CD or DVD "writer" in your computer if you don't already have one. These units are quite inexpensive ($50 or so) and come with easy installation instructions so you can install it yourself -- all you need is a screwdriver and about fifteen minutes. You also need some blank CD-R disks (a stack of 100 runs about $15) to use for making the backups. Once the drive and software is installed ("writing" software usually comes with the drive) it's a simple matter to start the software, select the folders to copy to the CD (or DVD) and click GO.
Or, if your computer has a USB port and you're squeamish about installing a CD or DVD writer, go to your computer store (or Target, Best Buy, Wal-Mart or probably even a local drugstore) and purchase two or three USB flash drives for about $50. This are simple items to use: you plug one into the computer's USB port, wait a few moments for Windows to recognize it and assign a drive letter to it (it typically might become drive E: or F:) and then simply use Windows' built-in copy and paste functions to copy whole folders to that flash drive letter. When it's done, just unplug it from the USB port. Talk about easy!
You could also purchase a USB-powered ZIP drive and ZIP disks at your local Best Buy or computer store. This is a little more expensive than the USB flash drive method, but it works similarly, and on a one-for-one basis, ZIP disk media is generally less expensive than a flash drive. You plug the ZIP drive into the USB port, wait for Windows to recognize it and assign a drive letter to it, and you use it the same way using Windows' built-in copy/paste functions.
So, it turns out the solution is a lot easier than having gone through all that information about backup systems, but if you're reading this paragraph, you probably know more now about backup equipment options than you did before, and that has to worth something! But if you want to read a little more on the topic of backups, click here: More Backup Info.