Related Manuals for ICP Chapter C
Summary of Contents for ICP Chapter C
- Page 2 In the previous chapter we installed the ICP Controller in a PCI computer and connected the SCSI devices. Now these SCSI devices must be prepared in order to run with your operating system. This Quick-Setup chapter should help you to get started quickly. Quick-Setup shows four examples on how a single SCSI hard disk, a Mirroring Array Drive (RAID 1), a RAID 5 Array Drive and a RAID 5 Array Drive with a Hot Fix drive are installed: Example 1:...
- Page 3 How many physical SCSI hard disks are to be integrated in the Array Drive ? Which redundancy level ought to be achieved ? Should RAIDYNE automatically recover redundancy in the event of a disk failure ? Or, in other terms: Are Hot Fix drives needed ? Before we go through these examples step by step, we would like to explain a few terms and relations important for the basic understanding of the ICP Controller firmware.
- Page 4 According to the adjusted stripe size (e.g., 16 KB) and the number of hard disks, the data blocks are split into stripes. Each stripe is stored on a separate hard disk. Especially with sequential read and write operations, we can observe a sig- nificant improvement of the data through- put.
- Page 5 RAID 4 works in the same way as RAID 0. The data are striped amongst the hard disks. Addi- tionally, the controller calculates redundancy data (parity information) which are stored on a separate hard disk (P1, P2, ...). Even when one hard disk fails, all data are still fully available.
- Page 6 The idea behind RAID 10 is simply based on combination RAID 0 (Performance) and RAID 1 (Data Secu- rity). Unlike RAID 4 and RAID 5, there is no need to calculate parity information. RAID 10 disk arrays offer good performance and data security.
- Page 7 Whenever you load GDTSETUP and select the desired ICP Controller, it comes up in its EXPRESS Setup mode. This mode does not require any previous knowledge. If you choose this function, GDTSETUP carries out the complete installation entirely on its own, providing you for example with a fully operational RAID 5 Array Drive with optimized settings (for in- stance, with all SCSI features of a given drive activated).
- Page 8 GDTSETUP scans the system for "free" hard disks (i.e., drives which are not yet part of other Host Drives). Use the <SPACE>-bar to select the desired hard disks (they are marked with an "*"). On the right side GDTSETUP offers highlighted the possible configurations with these drives.
- Page 9 After choosing a configuration type for an Array Drive, GDTSETUP displays a security re- quest. After the confirmation, the Host Drive is automatically built up and configured. After leaving GDTSETUP the parity information is generated.
- Page 10 For chapter C, we do not use this function, but give detailed instructions on how to set up a single disk and disk arrays with GDTSETUP and its Enhanced Setup. Both GDT firmware versions (Standard and RAIDYNE) are based on four fundamental levels of hierarchy.
- Page 11 After a capacity expansion of a given Array Drive the added capacity appears as a new Host Drive on this level. It can be either used as a separate Host Drive, or merged with the first Host Drive of the Array Drive. Within GDTSETUP, each level of hierarchy has its own special menu: Menu: Configure Physical Devices Menu: Configure Logical Drives...
- Page 12 If GDTSETUP was loaded this way, there is an "R" (ROM) behind the version number. 2. Load GDTSETUP from disk under MS-DOS. Boot the MS-DOS-operating system (either from a boot-floppy or from an already existing boot drive, i.e., IDE-hard disk etc.). In or- der for GDTSETUP to work properly, you have to load the device driver GDTX000 first.
- Page 13 The main menu gives you the following options. As mentioned before, we have to go through levels 1 to 4 to install the SCSI hard disk (with almost nothing to do on levels 3 and Now activate the menu Configure Physical Devices (level 1). A list appears showing all hard disks found on the ICP Controller’s SCSI channels.
- Page 14 (Note: On Channel B, SCSI ID 0, is a drive which has been already initialized before. This is not relevant for our examples). The Configure Disk menu appears which shows various options. For our example we choose the Initialize Disk menu option and press <ENTER>. The parameters within this menu can be changed by pressing <ENTER>...
- Page 15 1. Sync. Transfer: Enable The SCSI-bus allows an asynchronous and a synchronous transfer. Every SCSI device must be able to perform the first type of transfer, the second one is optional. The advantage of the synchronous transfer lies in a higher data transfer rate as the signal transfer times on the possibly long SCSI-cable have no influence on the transfer rate anymore.
- Page 16 Press <Y> and we are back on the main screen of level 1 and see that the initialization- status of the SCSI device has changed. We now leave level 1 (by pressing the <ESC>-key) and are back in the main menu. Now, with the cursor keys select Configure Logical Drives and go to level 2 by pressing <ENTER>.
- Page 17 The main screen of level 2 appears. Move the selection bar to Create new Logical Drive and press <ENTER> . Note: The already existing Logical Drive in this list has no relevance for our example.
- Page 18 Select the initialized hard disk with the <SPACE>-bar (it becomes marked with an "*") and press <ENTER>. For security reasons, you will be asked again if you want to use the selected disk to create a Logical Drive. As we are sure of our choice, we confirm with <Yes>. GDTSETUP allows you to limit the hard disk size for this Logical Drive.
- Page 19 The dialog box is closed and we are back in the main menu of level 2. As you can see, we have already created a new Logical Drive of the type Disk. The name of the Logical Drive is assigned automatically and contains the channel description and the...
- Page 20 SCSI-ID after the "_" . This can serve as a reminder when you install a complex system with many drives. (Naturally, you may change the name.) This concludes the installation on level 2. Now press the <ESC>-key to leave this screen. Since we have only a single disk assigned to a Logical Drive, there is nothing to do in the Configure Array Drives menu, thus we go directly to the Configure Host Drives menu and have no Step 4.
- Page 21 We should not forget to mention, that if you would have selected Create new Host Drive, this would have lead you to the same menu as the Express Setup mode. But this example is an exercise which should help you to gain a better understanding of how the ICP Controller and GDTSETUP work.
- Page 22 As we are done with the installation and therefore definitely want to leave GDTSETUP, we press any key. IMPORTANT: Always end GDTSETUP by leaving the program in the regular way (do not warm-boot with CTRL-ALT-DEL or cold boot by pressing the RESET button). Cer- tain information is only transferred to the controller when you leave GDTSETUP in the regular way.
- Page 23 This example is applicable to all ICP Controllers. It is our intention to install a Mirroring Array consisting of two identical hard disks. In the classical terminology of the RAID levels this is called a RAID 1 disk array. We presume that the controller and the SCSI hard disks have been properly installed. Step 1 of the installation is the same as in the first example, therefore we do not explain it again.
- Page 24 Note: The already existing Logical Drive in the first position of this list has no relevance for our example. The second entry was created before. Select the initialized hard disk with the <SPACE>-bar (it becomes marked with an "*") and press <ENTER>.
- Page 25 For security reasons, you will be asked again if you want to use the selected disk to create a Logical Drive. As we are sure of our choice, we confirm with <Yes>. GDTSETUP allows you to limit the hard disk size for this Logical Drive. This becomes interesting when you configure disk ar- rays.
- Page 26 As you can see, we have created another Logical Drive of the type Disk. The name of the Logical Drive is assigned automatically and contains the channel description and the SCSI- ID after the "_" . This can serve as a reminder when you install a complex system with many drives.
- Page 27 Since we want to create a new Array Drive press <ENTER>. Note: The first entry in this list has no relevance for our example. Move the selection bar to the second entry and press the <SPACE>-bar. The entry is marked with an "M"...
- Page 28 Move the selection bar with the cursor key to the next entry and press the <SPACE>-bar, again. It is marked with an "*"(pressing the <SPACE>-bar again undoes your choice). When the Logical Drive is selected, confirm with <ENTER>. GDTSETUP displays now a list of possible RAID levels, available with the number of Logical Drives selected.
- Page 29 GDTSETUP displays a security request, which we answer with <Y>. As you can easily recognize, we have created a new Array Drive of the Type RAID-1. Its state is build. When we leave GDTSETUP at the end of this example, you will see that the ICP Controller automatically copies the data of the first Logical Drive (our master) to the second Logical Drive.
- Page 30 The functioning of a RAID-1, or mirroring, disk array, is easy to understand: On the ICP Con- troller, one write-access from the host computer is transformed into two write-accesses (to both Logical Drives forming the mirroring array). If the two Logical Drives are built of hard disks, which are connected with different SCSI channels of the ICP Controller, both write- accesses are performed simultaneously (this method is often called Disk Duplexing).
- Page 31 minated SCSI-bus will cause malfunctions of the connected devices and data transfer problems. The ICP Controller for this example has three independent SCSI channels: A, B, C. In our example, two SCSI hard disks are connected to channel A (DR1, DR2), one to channel B (DR3) and two to channel C (DR4, DR5).
- Page 32 This can be done in two ways: a.) Load GDTX000 from the DOS-command level by typing in GDTX000<ENTER> b.) Load GDTX000 automatically through the CONFIG.SYS file (DEVICE=GDTX000.EXE) Note: GDTSETUP.EXE as well as GDTX000.EXE are on the System Disk - DOS. If GDTSETUP was loaded this way, there is a "D"...
- Page 33 GDTSETUP only allows you to work on Direct Access Devices (and therefore not on tape drives, DATs, CD ROMs etc.). The screen shows you: the channel to which a SCSI device is connected which SCSI-ID the drive has (the entry SCSI I/O Processor stands for the corresponding SCSI channel of the ICP Controller.
- Page 34 1. Sync. Transfer: Enable The SCSI-bus allows an asynchronous and a synchronous transfer. Every SCSI device must be able to perform the first type of transfer, the second one is optional. The advantage of the synchronous transfer lies in a higher data transfer rate as the signal transfer times on the possibly long SCSI-cable have no influence on the transfer rate anymore.
- Page 35 4. Protocol This can be either SCSI-II or SCSI-III. If you select SCSI-III make sure, that your hard disk supports this protocol. Most new multi- GB hard disks support SCSI-III. To enable Ultra (FAST-20) transfer rates (Narrow: 20 MB/s; Wide: 40 MB/s), SCSI-III protocol is required. 5.
- Page 36 Initialize the remaining four SEAGATE drives as described above, that is: Select the device with the cursor keys and press the <ENTER>-key Choose the settings shown above Carry out the initialization When the initialization of the last SCSI device has been completed, the screen should look as follows (a small i (i = initialized) must follow the SCSI-ID of each SCSI device):...
- Page 37 Important: Moving to the next level (Configure Logical Drives) only makes sense if all SCSI devices you need there are initialized. We now leave level 1 (by pressing the <ESC>-key) and are back in the main menu. Now, with the cursor keys select Configure Logical Drives and go to level 2 by pressing <ENTER>.
- Page 38 Note: The already existing Logical Drive in this list has no relevance for our example. Select the initialized hard disk with the <SPACE>-bar (it becomes marked with an "*") and press <ENTER>. For security reasons, you will be asked again if you want to use the selected disk to create a Logical Drive.
- Page 39 ure disk arrays and you want to make sure that future drives you want to bring into the disk array (e.g., for the capacity expansion or for replacement purposes) fit. It would be bad luck if the new drive only had 2067 MB. GDTSETUP couldn't accept it. To avoid this occuring, you could limit the capacity of each drive to 2000 MB.
- Page 40 As you can see, we have already created a new Logical Drive of the type Disk. The name of the Logical Drive is assigned automatically and contains the channel description and the SCSI-ID after the "_" . This can serve as a reminder when you install a complex system with many drives.
- Page 41 Since we want to create a new Array Drive press <ENTER>. Note: The first entry in this list has no relevance for our example. Move the selection bar to the second entry and press the <SPACE>-bar. The entry is marked with an "M"...
- Page 42 Move the selection bar with the cursor key to the next entry and press the <SPACE>-bar, again. It is marked with an "*"(pressing the <SPACE>-bar again undoes your choice). Re- peat this selection until all five Logical Drives are marked. When the last Logical Drive is selected, confirm with <ENTER>.
- Page 43 RAID 0 pure data striping without redundancy RAID 1 disk mirroring RAID 4 data striping with dedicated parity drive RAID 5 data striping with striped parity RAID 10 RAID 0 combined with RAID 1 In our case we take RAID-5 and press <ENTER>.
- Page 44 GDTSETUP asks for the Stripe Size. This is the size of the stripes into which the data is di- vided. The default is 32KB which we leave for this example and therefore press <ENTER>. (Note: 32KB stripe size is suggested because in various performance tests it has proved to be the best value.).
- Page 45 It's done ! We succeeded in setting up a RAID 5 disk array. The screen shows that the disk array is cur- rently in an idle state. Later in this chapter, we shall explain the different states a RAIDYNE disk array can assume. We are now back in the main menu of GDTSETUP.
- Page 46 Press <ENTER> to get a list of possible menu options. We should not forget to mention that if you would have selected Create new Host Drive, this would have lead you to exactly the same menu as the Express Setup mode. But this example is an exercise which should help you to gain a better understanding of how the ICP Controller and GDTSETUP work.
- Page 47 when there is no operating system loaded and the INT13H extension of the ICP Controller has not yet been activated. We are now back in the main menu of GDTSETUP. The installation is completed, and we therefore leave GDTSETUP by pressing the <ESC>-key. The following message appears: As we are done with the installation and therefore definitely want to leave GDTSETUP, we press any key.
- Page 48 Press <ENTER> and move the selection bar to the Build/Rebuild Progress menu. Press <ENTER> . From the progress information slider, we can easily see, that the 8 GB disk array is already built up 11% and that the estimated time for the build process is 31 minutes. Note: During the build process the disk array is fully operational, but not yet redundant.
- Page 49 At the end of this build process the disk arrays state becomes ready (fully redundant). Now press <ENTER> and move the selection bar to the Parity Verify menu. Press <ENTER>. RAIDYNE now checks the correctness of the redundancy information (i.e., calculates the redundancy information anew and compares it with the already existing information).
- Page 50 Depending on how large the disk array is, this check may take quite a long time, however, it can be aborted by pressing <ESC>. Parity Verify is a diagnosis function which enables you to verify the consistency of a disk array every now and then. We interrupt the verification by pressing <ESC>.
- Page 51 After selecting the failed Logical Drive, press again <F2> to obtain detailed information on the physical drive which has actually failed. Important: Even if we reconnected the power supply to DISK_B2 before loading GDTSETUP, DISK_B2 would not be included in the disk array again. If you decide to use the failed hard disk again, it is best if you reconnect the drive to the power supply and do a cold boot.
- Page 52 After loading GDTSETUP select the Configure Array Drives menu. Select the Replace Array Com- ponent menu Press <ENTER> . GDTSETUP recognises the previously failed drive again (it was not really defective) and asks if it should be integrated into the disk array again. Answer <Yes>...
- Page 53 After the completion of this process, the disk array's state changes into ready again. A few words on the replacement of a defective hard disk of a disk array. If a hard disk belonging to a disk array for which no Hot Fix drive had been assigned should fail, you should replace this defective hard disk with a new one as soon as possible.
- Page 54 be accessed during the Hot Plug drive replacement. The Hot Plug should be carried out as quickly as possible. The ICP Controllers also support the Intelligent Fault Bus (DEC ™ fault bus) and SAF-TE. Both industry standards allow for a replacement without any program interaction. Simply unplug the defective drive and plug in a new one.
- Page 55 When the last Logical Drive is selected, confirm with <ENTER>. GDTSETUP now displays a list of possible RAID levels available with the number of Logical Drives selected. RAID 0 pure data striping without redundancy RAID 1 disk mirroring RAID 4 data striping with dedicated parity drive RAID 5 data striping with striped parity...
- Page 56 In our case we take RAID-5 and press <ENTER>. GDTSETUP asks for the Stripe Size. This is the size of the stripes into which the data is di- vided. The default is 32KB which we leave for this example and therefore press <ENTER>. (Note: 32KB stripe size is suggested because in various performance tests it has proved to be the best value.).
- Page 57 GDTSETUP allows you to limit the capacity of the disk array. This may be of interest if your installation requires an exact size for a disk array. Normally, the full capacity is used. In our example we press <ENTER> . We succeeded in setting up a RAID 5 disk array.
- Page 58 Press again <ENTER> and move the selection bar to the Add Hot Fix Drive menu. Press <ENTER>. GDTSETUP now displays a new dialog-box containing all the Logical Drives apt to serve as a Hot Fix drive (one criterion for this suitability is the drive's capacity, i.e., it has to be large enough).
- Page 59 Press <ENTER>. GDTSETUP offers two different Hot Fix types: A private Hot Fix drive is only available for one specific disk array. A Hot Fix drive in a Hot Fix Pool can be made available to several disk arrays (presuming that the capacity fits). In our example we choose the Private Hot Fix drive and press <ENTER>...
- Page 60 After pressing <F2> we get detailed information on the structure of the disk array. The last entry refers to the Priv. Hot Fix drive. We have already seen this form before, with the only difference that DISK_C2 has been as- signed to be the Hot Fix drive.
- Page 61 1. After a short while, GDT's alarm signal is heard. (Note: the alarm only goes on when the RAID 5 Array Drive is accessed.) 2. RAIDYNE activates the so-called fail operation mode. In this mode, the disk array re- mains fully operational. The data of the failed drive is reconstructed by means of the re- dundancy information stored on the other drives.
- Page 62 drive, set its SCSI ID to 3 and connect it to the connector of SCSI channel B, where the pre- viously failed drive was connected to and to the DC-power supply. Before switching on the system again, check that the SCSI termination of the new drive is identical to the old one. After switching on the system again, load GDTX000 and GDTSETUP and initialize the new drive.
- Page 63 DISK_B3 is our new Logical Drive, which we want to use as a new Hot Fix drive. Change to the Configure Array Drives menu. Select our Disk Array and press <ENTER>. Select Add Hot Fix Drive and thereafter DISK_B3. Select Private Hot Fix and press <ENTER> . Press <F2>...
- Page 64 As we can see from the list, DISK_B3 has become the new Hot Fix drive for our RAID5 disk array. DISK_C2 is still invalid (this was our former Hot Fix drive), since the rebuild process is not yet completed. Now, after having demonstrated with examples 3 and 4 how RAID disk arrays are created with RAIDYNE (we hope you enjoyed it), we would like to return to the questions set down at the beginning of this chapter.
- Page 65 The desired usable disk space of the disk array as well as the following two issues have a direct impact on the number of physical hard disks needed. To come straight to the point, RAID 0 (data striping) does not imply any redundancy at all (the R in front of the AID is rather misleading).
- Page 66 Hot Fix drives are possible with all RAID 1, 4, 5 and 10 disk arrays. In order to assist the following considerations, we define the term time without redundancy, TWR. Set apart the time needed to set up the disk array (state build), the time without re- dundancy should be kept as short as possible.
- Page 67 The disk array will assume this state after the automatic activation of a Hot Fix drive or after a manual replacement carried out with GDTSETUP. The data and the redundant information are reconstructed and stored to the new drive. If the capacity or RAID level of an existing disk array is changed, the disk array changes its state into expand.