Serial Attached SCSI PortsWith two internal mini-SAS ports, the Areca ARC-1680i supports up to 128 SAS or SATA devices (with expander) for enhanced flexibility and speed.; RAID SupportThe Areca ARC-1680i supports multi-level RAID configuration including RAID level 0, 1,1E, 3, 5, 6, 10, 30, 50, 60 or JBOD for better performance, enhanced data security and flexible capacity upgrades. The smartpqi driver is the first SCSI driver to implement the PQI queuing model. The smartpqi driver will replace the aacraid driver for Adaptec Series 9 controllers. Customers running an older kernel (Pre-4.9) using an Adaptec Series 9 controller will have to configure the smartpqi driver or their volumes will not be added to the OS.

• Areca Scsi & Raid Devices Drivers
• Adaptec Scsi Drivers
• Download Scsi Drivers
• Areca SCSI & RAID Devices Driver

RAID Controllers

Areca high-performance ARC-1680 series PCIe to SAS RAID host controller can provide up to (128) SAS/SATA ll peripheral devices using SAS expanders. The controllers are based on the same RAID kernel of field-proven external RAID adapters and same device drivers with widely used SATA RAID controllers. Areca’s engineering team had well experienced in the PCI IDE Controllers for National Semiconductor, IDE Disk Cache Controllers for Buslogic, SCSI Disk Cache Controllers, SCSI Controllers, PCI Main board, EISA Main board and Local bus Main Board. Areca high-performance ARC-1680 series PCIe to SAS RAID host controller can provide up to (128) SAS/SATA ll peripheral devices using SAS expanders. The controllers are based on the same RAID kernel of field-proven external RAID adapter and same device drivers with widely used SATA RAID controller. Applications that benefit most features from these controllers include NAS, server RAID solutions.

Areca Scsi & Raid Devices Drivers

Step to move Mail, Home, KVM RAID

• See Move Mail RAID

New RAID cards: ARECA

The Areca cards in Pumpkin, Taro and Gourd (the new Einstein hardware) can all be accessed with a web browser. The interfaces are all on the backend network:

You log in as 'admin' with the standard root password missing the prefix part.

Areca CLI

The Areca cards can be accessed through the command line as root. The command areca_cli64 is installed on all machines with an Areca card. The Areca CLI Manual explains in full detail how to use the CLI interface. Here are a few commands that are quick and easy.

• areca_cli64 hw info - To monitor the Areca hardware
• areca_cli64 disk info - To view status of all the drives
• areca_cli64 disk smart drv=<drive number> - To view the smart data on that drive
• areca_cli64 disk sttest drv=<drive number> - To run a smart self-test on a specified drive

E-mail Alerts

All Areca cards should be configured to send out e-mail alerts about failed drives or other problems. Here's what you need to do to configure this feature:

• Login to the Areca web interface and select System Controls -> Alert By Mail Config
• Enter the FARM IP address for Einstein in the SMTP Server IP Address field.
• You need to enter an e-mail account and password for the Areca card to use for sending e-mail. Currently I (Adam) have them configured to use my account, but I plan to create an e-mail-only user account for this purpose.
• Enter a name in the MailTo Name field, accompanied by the address for that person in the Mail Address field.
• Set the Event notification configuration to Urgent Error Notification. This setting will limit e-mail alerts to only the most serious of problems. For some reason a user logging into the web interface is considered a 'Serious Error', and using that setting will result in e-mail alerts every time someone logs into the web interface, which is annoying.

Working with Areca RAID devices

These are my notes from testing out the Areca card in Gourd, and should serve as brief howtos for various features of the RAID cards.

Pass-through drives

Pass-through drives are not controlled by the RAID card. They function as an independent scsi device plugged directly into the system, and are not part of a RAID set. [Gourd] currently has two pass-thru disks set up in a software RAID. These are the steps I took to add a new pass-through device on [Gourd]:

1. Insert the drive into the drive bay
2. The drive should now be visible in the Areca web interface. Expand the 'Physical Drives' folder in the left column and then select 'Create a Pass-Through disk'.
3. Select the disk you want to create as a pass-through disk and then check the confirmation box before clicking the Submit button.

RAID Sets and Volumes

Setting up a hardware RAID on an Areca card is a two step process. First you have to add the drives you want to use to a RAID set. You need to make sure you add the correct number of drives for the RAID level you want to use, but beyond that all you're doing at this point is making a group of drives you can create a volume on. You'll choose the RAID level when you create the volume. To create a RAID Set:

1. Click 'Create a RAID Set' under RAID Set Functions
2. Select the drives you want to add to the RAID Set. You can only add Free drives to a new RAID set.
3. Confirm the operation and click Submit

You now have a RAID set, but in order to use it as a drive you need to create a Volume set. This is where you will select the level of RAID to use. The Areca card will only give you the options for the RAID levels that are possible on a given RAID set, so for example if you only have two drives you can't create a RAID 5 or 6, which requires at least 3 or 4 drives, respectively. The Areca cards support volumes of different RAID levels on the same set of drives. The important settings to bear in mind are the Volume name, which you should set to something more useful than 'Volume Set #00004', the RAID level, and the SCSI Channel/ID/LUN. Unless you have a reason to change them you can accept the defaults on everything else. To create a Volume Set:

1. Click 'Create a Volume Set'
2. Select the RAID set you want to create your Volume on and click Submit
3. Choose the settings you want to apply to the Volume Set, confirm the operation and click Submit

If you select background initialization you will be able to access the Volume immediately, but if you choose foreground initialization you have to wait for initialization to finish before using the volume. Depending on the size of the volume it may take a long time to initialize (two hours for a 500gb RAID volume, in my experience), so you might want to go and make yourself a cup of coffee.

Adding/removing scsi devices on the fly

When you create a RAID volume on the Areca card the system won't see it until you reboot. There is a way to add and remove scsi devices without rebooting by using the proc interface.

You should have the values for Channel, SCSI ID and LUN from when you added the drive, but if not they're listed next to the volume name on the Areca web management interface. Note that the following command takes four values, but you only get three from the Areca card. The values from the Areca card should be the last three, and the first value should be zero. Use this command as root (sudo won't work) to add a scsi device:

Once you've run this command your volume should appear in /dev/sd* with the other scsi devices. To remove this device you would use a similar command:

Possible rescue techniques

DO NOT ATTEMPT THIS WITHOUT TOP SUPERVISOR PRESENT

Really, this shouldn't even be here. Contact Maurik immediately. Don't even think about hosing the RAID drive.

Alert by Mail

The Areca cards in Gourd, Taro, and Pumpkin are configured to send e-mail alerts of any urgent errors or events. There are several categories of errors; urgent, serious and warning. It isn't clear how these errors are categorized, but I did discover that logging into the web interface is considered a 'Serious' event. In order to keep our mailing list from filling up with a bunch of notifications from every time someone logged into a RAID card's web interface I've set the cards to only send out notifications on 'Urgent' events.

In order to be able to send e-mail the RAID cards need to have a login and password to the mail server. I've given them my account info for the time being, but I intend to create a special account just for the Areca cards to be able to send mail.

Software RAID

RAID volumes in Linux are created using partitions, so the first step in creating a software RAID is creating the partitions you want to add to the RAID. These partitions must all be the same size. Once you have the partitions created you can use the mdadm tool to create a new RAID device. The command should look something like this:

Where mdX is the number of the RAID device you want to create, level is the RAID level you wish to use, raid devices specify how many partitions will be added to the RAID array, and the remainder of the arguments is the list of partitions you want to use for the RAID array. In order to create a RAID 1 array you would use something like the following example:

The file /proc/mdstat will display the status of the RAID device initialization. Depending on the size of the array it may take a while to finish initializing. You still should be able to format, mount and use the RAID device before initialization has finished, though the performance may not be optimal.

To fail a drive in a RAID array, use the following command:

To add a new device to a RAID array, use this command:

Rebuilding a Software RAID

Should /proc/mdstat show that a problem exists with one of the RAID arrays, you can rebuild it by performing the following steps (5.9.9.2. Rebuilding a RAID array):

• 1. Remove the disk from the raid array.
     • mdadm --manage /dev/md0 -r /dev/sdc3
  2. Remove the disk from the system.
  3. Using fdisk, replace the removed disk and re-format the replacement disk.
  4. Add the new disk back to the RAID array.
     • Note: In order to get the system (Gourd) to recognize the new drive you must go into the Areca card and delete the newly added drive as a hot spare and then add the drive as a passthrough under the menu Physical Drive.
     • Note: To make sure that the partitions match precisely, run fdisk on the working drive in the RAID array and use the cylinder numbers to create the partitions on the new drive just added.
     • mdadm --manage /dev/md0 -a /dev/sdc3
  5. To restore the disk, perform a 'software fail' the previous spare slice:
     • mdadm --manage --set-faulty /dev/md0 /dev/sdc3
  6. The system will now attempt to rebuild the array on the replaced disk. Use the following command to monitor status:
     • watch -n 1 cat /proc/mdstat
  7. When the array is finished rebuilding, remove and then re-add the software-failed disk back to the array.
     • mdadm --manage /dev/md0 -r /dev/sdc3
     • mdadm --manage /dev/md0 -a /dev/sdc3
  8. Check the array.
     • mdadm --detail /dev/md0

Old RAID cards

The documentation for the controller should be available in /usr/local/doc/3dm2.There should be a deamon running, start it with '/etc/init.d/3dm2 start'With the deamon running, the device can be checked and manipulated using a web browser on the local machine pointing to http://localhost:888/. Log in as administrator with the root password.

More recently (2006) we no longer run this deamon, instead the RAIDS can be querried and controlled with tw_cli, in /usr/local/bin. Type tw_cli help for help. You must be root to run this program.

Examples (must be root):

Be totally wicked careful with any of the other commands PLEASE

TOMATO:

Contains a RAID with 12 Maxtor Diamond Max 10 drives (300GB, model number: 6B300S0).Data Sheet

OLD GOURD:

Contains a RAID with 8 Maxtor drives (251GB, Model number 7Y250M0)

RAID Drives

Drive Life Expectancy

This is a list of drives we have in our RAID configuration and their life expectancy. The pdfs where this information is found are located at:

Pumpkin

ST3750640NS

ST3750640AS

WDC WD7500AAKS-00RBA0

Endeavour

ST31000340NS

ST31000524AS

ST31000526SV

Drive Technology

Compare The Major Hard Drive Technologies

Serial ATA has been common technology in desktops and workstations for quite some time now. Market share in server environments has been growing steadily over the last couple of years. The interest for Serial ATA is certainly there. The server market is very conservative by nature, however. Many businesses still prefer SCSI for mission critical applications. Reliability and availability are top priority. Serial ATA still has a long road ahead in winning the trust of corporate users. There are many true and false stories circling around about the performance of SCSI systems in serverdow workloads. On this page, we will make a direct comparison between SCSI and SATA RAID.

Adaptec Scsi Drivers

There are many differences in the interface technology and in the commands executed. SCSI has a robust tagged command queuing implementation to allow multiple commands to be outstanding which provides significant performance gains for drives or controllers by being able to order the commands in an optimal execution manner. ATA only allows a bus release that is mistakenly called command queuing. The implementation on the class of disk drives that support ATA is different as well.

Download Scsi Drivers

ATA drives are cheaper than SCSI or Fibre Channel drives and there's a reason. SCSI and FC drives use a processor for executing the commands and handling the interface and a separate processor controlling the head positioning through servos. ATA drives use a single processor for both which means that if the rotational positioning requires more adjustments due to factors such as rotational vibration or wear, more processor time will be dedicated for that which can affect the performance of the drive. Because of this, you will usually see a lower RPM for the ATA disk drive and also a shorter warranty period. But it is cheaper and can be a very good, economical solution for many environments and applications.

SATA configurations perform admirably well in file server and streaming media scenarios, while SCSI configurations are king of the hill in database applications

Areca SCSI & RAID Devices Driver

We have no intention to pass sound judgements about the reliability of the Serial ATA solutions reviewed in this article. However, based on the features of the adapters in this test we can say that SATA RAID need not be inferior compared to alternatives using a SCSI interface. The high-end SATA RAID adapters are supporting all the important availability features found on SCSI RAID-adapters. The SATA RAID-adapters made by Areca and LSI Logic have been directly ported from architectures which have been used in SCSI RAID systems for many years. So with respect to features, Serial ATA is certainly up to the job of handling enterprise storage.

That leaves the question if Serial ATA can offer acceptable performance in workstation and server environments. Thanks to the large number of RAID adapters which have been tested by us in the previous months, we can certainly say something meaningful about the performance of SATA and SCSI RAID systems. Besides performance, price and rack density are important selling points that need to be taken into consideration. Does one give priority to the highest performance or the lowest price/capacity, or is performance and capacity per height unit important? These different priorities leave us with several possible interpretations of the results you find on this page. For example, a SATA RAID setup using six 10.000rpm hard drives can be cheaper and better performing than a SCSI RAID setup, whereas SCSI setups with 15K hard disks will realize a higher performance per height unit. No discussion is needed about the answer to the question which configuration provides the lowest price per gigabyte. Serial ATA will always have the advantage in this area.

SATA configurations perform admirably well in file server and streaming media scenarios, while SCSI configurations (dependent on the specific type of adapter and harddisks) are king of the hill in database applications. With the arrival of Serial ATA II all shortcomings of the ATA-interface concerning performance and reliability have been solved. A new generation of hard disks, supporting native command queuing, will be able to offer even better performance than the Raptor WD740GD? in this comparison. At the same time, the arrival of Serial Attached SCSI and future SAS-harddisks with spindle speeds of 22,000rpm ensure that the SCSI interface will consolidate its unique featureset and its performance advantage in certain workloads. SCSI, thanks to its higher level market position, will always be the technology to profit first from technological advancements. These technological advantage will not only affect harddisk performance, but will also have its effect on RAID adapter performance. The higher priced SAS RAID solutions will be equipped with the latest generation I/O processors and larger amounts of cache memory, for instance. In the low-end server market - single and dual processors sytems using direct attached storage - Serial ATA will become a mature and powerful alternative to SCSI.