SoftRAID 4.2

SoftRAID 4 contains a wealth of new features which we are really excited about," said Mark James, VP Sales. "SoftRAID 4 has many features which will make your life easier whether you're a system administrator who runs a group of servers, a consultant who has to keep track of the health of clients? Macs, or a professional who has to make sure his or her business is protected against disk failure or human error. We wanted to make this the best RAID solution for Mac OS X and I think we've succeeded."

SoftRAID 4 includes these key features, many of which are not available on any other RAID product for Mac OS X:

• Accelerated Mirror Rebuilds: mirror rebuilds can now take less than 10 minutes even on 1 - 2 TB volumes.
• Email Notification: the SoftRAID Monitor can send out email messages in response to error conditions to ensure that you know when things are going wrong before it?s too late.
• Command Line Interface: there is now a SoftRAID command line interface. You can check the status of your SoftRAID volumes, start a mirror rebuild or perform most SoftRAID functions remotely, even from your iPhone.
• Checking SMART Status on Disk: the SMART status on every disk is checked every time you launch the SoftRAID application and every 24 hours your Mac is running. In addition, the parameters returned with the SMART status are used to determine if your disk is more likely to fail in the next couple of months.
• Disk Hours of Use: SoftRAID now keeps track of how many hours each disk has been used. This will allow you to replace old disks before they fail.
• Validating Volumes: you can now read every sector on a volume even when it is in use without interrupting your work. For mirror volumes, the data on each disk in the mirror is compared to ensure that all disks contain identical copies of the volume.
• Certifying and Verifying Disks: new disks can now be certified before you use them to ensure that each and every sector is reliable.
• Support for SSDs and Disks with 4 KB Sectors: SoftRAID now has complete support for SSDs and disks with 4 KB sectors.
• The SoftRAID Log: all SoftRAID specific errors and events are now written to one log file. You can monitor the health of your SoftRAID disks and volumes without wading through all the diagnostic messages in the system.log file

At this point, the only known problems with SoftRAID 4 are the lack of documentation. Rather than hold off the release for another several weeks, we decided to ship version 4 and release the documentation with the next upgrade. If any of the new features are confusing and you cannot find the answer to your question in this document, please do not hesitate to contact us via email sales@softraid.com.

 

Accelerated Mirror Rebuilds

This version of SoftRAID includes a completely redesigned RAID architecture. At its heart is a RAID engine, a software emulation of a RAID controller which allows us to more easily add additional RAID levels in the future. Unlike SoftRAID 3.0 (and most RAID controllers), this RAID engine can actually perform many RAID operations at exactly the same time. The number of simultaneous RAID operations is limited only by the number of processors in your Mac. That means that with the latest Mac Pros which have 8 cores and HyperThreading, SoftRAID can actually perform 16 simultaneous RAID operations. Our testing shows that this new RAID engine is twice as fast at performing full mirror rebuilds than SoftRAID 3.

In addition, the new RAID engine keeps track of not only which disks are out of sync in a mirror, but also which parts of those disks need rebuilding. If you only write to the first 1% of a volume while a secondary disks is disconnected, then only that 1% will be rebuilt when the disk gets reattached. This dramatically reduces mirror rebuild times; a 1 TB volume can usually be rebuilt in under 10 minutes (with 20 GB of changes).

 

Email Notifications from SoftRAID

The SoftRAID Monitor now has the ability to send out email messages when error conditions arise. These email messages can be sent out even when there is no one logged into you Mac and do not require you to configure Apple’s Mail application. Email notifications can be sent out not only in response to error conditions (disk errors, SMART test failures, predicted disk failures) but also in response to routine events (mirror rebuilds completed, Mac restarted) and when certain thresholds are reached (high network activity, low free space on a volume or high cpu utilization).

The email engine in the SoftRAID Monitor supports an unlimited number of recipients and up to two outgoing email servers. That way, if one email server is unavailable, your email notification will still be delivered. The outgoing mail can be delivered over SSL or TLS connections. A convenient popup menu makes configuring the outgoing email server settings a breeze for many popular email providers.

 

SoftRAID Command Line Interface

SoftRAID now automatically installs a tool which provides access to most features from the command line. In fact, this tool is the same one which the SoftRAID application uses to perform most of its functions. The tool, called softraidtool, gets installed the first time you run the SoftRAID application and can be accessed from any terminal window by simply typing “softraidtool”.

Running softraidtool requires root access (e.g. sudo softraidtool...) for any function other than simply getting the current status of a disk or volume. This prevents an unauthorized user from erasing your SoftRAID volumes. If you want to remove SoftRAID, the softraidtool gets removed, along with the driver, the SoftRAID Monitor and all the SoftRAID specific preferences when you select Uninstall SoftRAID from the Utilities menu.

The commands for softraid tool all take the form:

softraidtool [disk|volume] identifier command parameters

For instance, if you want to get the status of the disk at disk3, you would type “softraidtool disk disk3 info” and if you wanted to get the status of your boot volume, you would type “softraidtool volume / info”. For a complete list of commands, simply type “softraidtool help” in a terminal window. In addition, the last section of this document contains a more detailed description of all the commands which are available.

If you wish to use the command line interface to remotely use softraidtool from another Mac or iPhone, you must enable Remote Login in the Sharing pane of System Preferences. In addition, you must make sure that your firewall can forward requests from the Internet to the Mac running SoftRAID. Please only do this if you have taken adequate security precautions (e.g. are using a strong password, etc.).

 

How SoftRAID Tests the SMART Status of Disks

SoftRAID obtains the SMART status of disks whenever the SoftRAID application is launched. In addition, the SoftRAID Monitor checks the SMART status of your disks everytime your Mac starts up and every 24 hours after that. If the SoftRAID Monitor discovers a disk which fails the SMART test or is predicted to fail (see below), it will: display a dialog, write to the SoftRAID log file and send out an email notification (if you have email notification configured). This ensures that you will be notified of impending disk failure even if you are not physically located near the Mac running SoftRAID.

Our interpretation of the SMART status of disks is based on the study performed by Google on 100,000 SATA disks over a two year period. During this study, they found that even when a disk has not failed the SMART test, some of the values returned in SMART status are indicators that a disk is 20 - 60 times more likely to fail in the next few months. SoftRAID now notifies you when a disk has one of these indicators. This allows you to move your important data off of a disk which is likely to fail before it stops working completely. If you wish to not receive these notifications, they can be disabled in the SoftRAID preferences.

 

Hours of Use on Disks

SoftRAID now reports the hours of use for all disks. For disks which support SMART, this value is the actual number of hours the disk has been turned on (either with the platters spinning or when they are stopped). We recommend that you replace disks with rotating platters after 20,000 hours of use as the incidence of failure can increases substantially after that point.

On disks which don’t support SMART, an hours of use counter is created the first time the disk is initialized with SoftRAID 4.0. This counter will continue to increase even if you later reinitialize the disk. The counter will be set back to zero if convert a SoftRAID disk to Apple Disk Utility Format.

 

Validating Volumes

Ever wonder if all the sectors of a volume are actually readable? SoftRAID 4 adds the ability to validate volumes. This function uses the new RAID engine. It reads every sector of a volume at the device level, bypassing the file system cache. This allows us to ensure that all the sectors on your volume can be read. Since the RAID engine is part of the SoftRAID driver, you can keep validating a volume even if the SoftRAID application is not running.

On mirror volumes, each disk in the mirror volume is read to ensure that they all contain identical copies of the volume’s data. Mirror volumes may need to be rebuilt before they are validated the first time to ensure that all the sectors on each disk are identical. All subsequent validate operations require no rebuilds.

 

Certifying and Verifying Disks

Most new disks you purchase have not had all their sectors tested when you receive them. On a 2 TB disk, this would take an extra 10 hours in the factory for each an every disk drive. Disk manufacturers can’t afford to perform this test on each and every disk they ship.

SoftRAID now allows you to certify a disk before you start using it. SoftRAID writes a pattern to each and every sector on the disk and then reads it back to ensure the every sector on the disk is reliable. This process can be repeated again with a different pattern to further ensure that the disk is reliable. You can specify that a certify operation takes up to 8 passes, each with a different pattern. The last pass always writes zeros to every sector.

We recommend three passes as the best value for new disks being placed into use. For old disks which are being reused, we recommend all 8 passes. SoftRAID’s certify function is also a great way to make sure that the CF or HDSC flash cards are totally reliable before you use them in your digital camera. Remember that certifying a disk will write to every sector, overwriting any volume or files on that disk.

If you want to make sure that a disk is working properly and don’t want to lose any data on it, you can use the verify disk function in SoftRAID 4.0. This function will read every sector of a disk and ensure that it is readable. This can be performed on a disk even if it is not initialized with SoftRAID however it does require the SoftRAID applicati on to be left running. We also recommend that you only verify disks if all the volumes on that disk have been unmounted.

Why does SoftRAID write zeros on the last pass of a disk certification? Data recovery companies, like DriveSavers Data Recovery, Inc., have told us that it is much easier to recover data from disks which have been filled with zeros before use. In the unlikely event that your disk fails, you don’t have a backup and you need to use a data recovery company to recover your lost files, we want to make it as easy as possible to get your files back.

 

Support for SSDs and Disks with 4 KB Sectors

There is now specific support for SSDs (solid state disks) and disks with 4 KB sectors. SoftRAID recognizes SSDs and changes the disk failure prediction algorithm for them. It also allows you to use a 16 KB stripe unit size when creating a stripe with two or more SSDs. This has been shown by Lloyd Chambers to produce better performance than larger stripe unit sizes (http://macperformanceguide.com/VirtualMemory-MacBookPro.html).

Note: SoftRAID may notify you that some older SSDs are predicted to fail. This occurs when the firmware on the SSD does not correctly notify Mac OS X that it is a solid state device. The algorithm SoftRAID uses parameters in the SMART status and is only valid for disks with rotating platters. SoftRAID ignores these SMART parameters if it knows a disk is an SSD. If you encounter this problem, please contact the manufacturer of your SSD for a firmware upgrade so that your device will be correctly identified by Mac OS X.

 

The SoftRAID Log

SoftRAID now logs all SoftRAID specific events and errors to a log file. This gives you one place to go when you want to know what is happening with SoftRAID on your Mac. You can view the log file either by selecting Show SoftRAID Log under the Utilities menu or by opening the file at /Library/Logs/SoftRAID.log using the Console application.

 

Using the Trial Version of SoftRAID

You can use SoftRAID on a trial bases for 30 days for free. At the end of the 30 day period, your SoftRAID volumes will still mount and you can use all the files on them but most other SoftRAID features will be disabled. If you wish to continue using SoftRAID, you can purchase a license from our web site. This will provide you with a serial number which you can use to unlock SoftRAID. Once the serial number has been entered, you will be able to use SoftRAID normally again. If you decide not to continue using SoftRAID, you can convert your SoftRAID volumes back to normal Macintosh volumes even after the 30 day trial period has expired.

 

Getting Help with SoftRAID

If you are experiencing problems with SoftRAID, please send email to support@softraid.com. Your purchase of SoftRAID 4.0 comes with one year of free technical support via email. If you wish phone support, you can purchase it on a incident by incident basis or for an entire year. Most users, once they experience our prompt response to support emails, opt not to purchase phone support.

SoftRAID 4.0 includes an incredibly powerful report generator for helping us figure out the nature of your problem. If you choose, Generate Report for Tech Support from the Utilities menu, you will generate a file which allows us to quickly pinpoint the nature of your problem. In addition, if you choose the option to Include extended disk and volume info, you will be sending us the partition maps and volume headers from your disks. In many instances, this information allows us to recover volumes which have been deleted by accident. (We remotely recovered an accidentally deleted AppleRAID mirror on a server at a video production facility in Lebanon using these Tech Support Reports during our beta period.)