Broken Fan on Dell PowerEdge

Dell PowerEdge fan unitAn interesting problem worth noting that happens on Dell PowerEdge systems is fan failure. There can be multiple causes of this

  • The fan may wear out
  • It may be switched off in the computer settings
  • The power lead to it may become disconneted

During a recent site visit to a Manchester with a broken Dell server, we discovered the cause of failure to be a non functioning fan. This had resulted in the hard disks becoming overheated and the system failing. Here’s how we fixed the fan problem:

To locate a fan, right-click the bad fan and click Properties. The Enclosure ID field indicates the ID number of the enclosure where this fan is located. Be aware that the enclosure ID number displayed by Array Manager does not match the Enclosure ID set on the switch module ID indicator on the back of the PowerVault 660F or 224F enclosures. When the switch module ID indicators on all the enclosures are configured properly, the enclosure ID numbers start at 0 and continue sequentially through 7. The enclosure ID numbers displayed by Array Manager, however, start at 1 and continue sequentially through 8. For this reason, the enclosure ID number displayed by Array Manager will be one greater than the number set on the switch module ID indicator on the back of the PowerVault 660F or 224F enclosures. For example, if the switch module ID indicator identifies the enclosure as 0, the Array Manager enclosure ID will be 1.

See the Dell PowerVault 660F and 224F Storage Systems Installation and Troubleshooting Guide for information on how to troubleshoot the Advanced Cooling Module (ACM). See the Dell PowerVault 660F and 224F Storage Systems Service Manual for part replacement procedures.

After troubleshooting or replacing the ACM, go to the Array Manager console and click to expand the Arrays storage object, right-click the PV660F Subsystem storage object, and select Rescan from the context menu that comes up. This action will update the fan status within the GUI.

For a decent RAID primer, especially regarding user data, it’s preservation and what to do if the data is compromised, see the primer at http://raidrecovery.pen.io/

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Troubleshooting RAID NAS

An integral part of any IT professional’s job is the ability to investigate and solve problems with RAID and servers. This is known as “troubleshooting” and before we go on to discuss this, let’s clear up and common misunderstanding, the difference between RAID and Servers. Not all servers run RAID, but all RAID are types of servers. RAID is simply a way of enabling computers to use multiple hard drives in a clever way, improving file access speeds and also providing some form of data protection against file loss. RAID comes in a variety of flavours but we can make a general differentiation between smaller home systems and larger business ones.

RAID 5 writes data to all hard disksThe proliferation of NAS hard drives has bought RAID into the home user environment. Most NAS hard drives are multiple hard disk systems containing either 2, 4 or 6 hard drives. Usually these system don’t need to be any larger than this as the average amount of storage a home user needs is will be covered. Home systems run mostly RAID 1 or RAID 5. RAID 1 is called ‘mirroring’ and usually consists of 2 hard disks that are an exact mirror of each other. The idea here is that should one of the hard disks fail, the data is safely preserved on the other. It’s a simple idea that works well. Some 2 disk RAID systems run a RAID 0 structure and RAID 0 is a bad idea because the data stored on a RAID system is divided up between the two drives, with no complete files being stored on either hard drive. Instead when file access from the RAID 0 is requested, the files are constructed from both hard drives and presented as a full file. This only advantage this serves is that the data transfer speeds are incredibly fast. A huge downside is that the is no safety net should either of the hard drives break. Indeed a fail to either drive will result in the total loss of all data, because files are split divided across the two hard drives. Because of this short coming, RAID 0 is hardly used anymore, and understandable so.

The larger NAS hard drives consisting of either 4 or 6 disks run in either RAID 5 or RAID 6. Both these types of RAID provide decent file transfer speeds and offer data protection too. RAID 5 will allow for one of the disks to completely fail and for RAID 6, this becomes 2 hard disks. So, a 6 disk RAID 6 will still work fine if 2 of its drives break and there will be no loss of data.

Troubleshooting RAID and NAS is a skill in itself – many IT professionals are not up to the task as repairing RAIDs and NAS hard drives is something they very rarely have to do. Additionally, there is the added complexity that the user’s data is involved, and any wrong move often results in the user’s data being lost. In both home and work environments, this is bad news as it’s either going to result in the loss of things like family photos and other cherished memories, or it’s going to result in the loss of (sometimes crucial) business data.

Our advice is to not involve inexperienced (although well meaning) computer troubleshooters to attempt to recover the data from any type of RAID systems. This is especially important on the larger RAID 5 and RAID 6 systems, as the more disks that are involved, the more difficult it is to identify the problems and troubleshoot the repair. Instead engage a company that know about RAID and hard drives, such as Emergency RAID Data Recovery or Datlabs Data Recovery, whose RAID recovery pages can be found here http://www.emergency-raid-datarecovery.com and http://www.datlabsdatarecovery.co.uk/raid-data-recovery/.

Regional Locations for RAID and NAS Recovery

Whilst most RAID specialists have only one point of presence in the UK, Data Clinic have regional offices in London, Manchester, Liverpool, Birmingham, Leeds, Glasgow, Northampton, Sheffield and Southampton. They also have a countrywide emergency RAID service that can be called out to any business location. Their main RAID recovery page is here http://www.dataclinic.co.uk/raid-data-recovery/ and contains lots of relevant information.

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Troubleshooting Print Problems from Word and Excel

Much time as a PC technician is spent troubleshooting printing issues. Sometimes the print problem will come disguised as an application problem are careful questioning and investigation will be required to discover the true cause. One other occassions the primary issue is with the application – and more often than most techs would like to admit, the true cause is sometimes a mystery.

You receive a ticket stating that a user in the HR department is having trouble loading Microsoft Word and Excel documents on her PC and that print times to the printer are also long. The printer is a shared device attached to another PC in the same department. The user was able to load MS Office documents and print normally prior to today.

Initial Investigation

Locate the user and ask a few questions about the problem. Some relevant questions would be:

  • When did the problem first occur?
  • Have there been any recent configuration changes to the printer settings on the PC?
  • Were any changes made to the hardware, software or configuration settings of the computer prior to the problem first appearing?
  • Do any error messages appear when a print command is issued?
  • Do any error messages appear when loading the Word / Excel applications?
  • Are there any issues when you attempt a direct print?

 

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Changing Backup Tapes on a Server

changing a backup tapeChanging a backup tape on a server is a bit more involved than changing a cassette tape in your car’s tape player. Although changing tapes sounds like an entirely physical process, there is a software side of it too.

Tapes must be changed every day so that you always have the server’s latest information changes available in case you have to do a restore. This is an activity that will become a constant for you. However a backup tape isn’t going to do you much good if the backup process itself failed or if the data on the tape has become corrupted. You have to check on the status of the previous night’s backup before swapping tapes.

If given the responsibility of changing the backup tape on a server located at one of your company’s branch offices, you’ll need to verify that the backup was successful, report to your supervisor when a backup was not successful, remove and label last night’s tape, and insert a fresh tape for tonight’s backup.

How to Change a Backup Tape on a Server

  1. Sitting at the server’s keyboard, log on to the server as an administrator
  2. Double-click the icon for the server’s backup application on the Desktop
  3. After the program opens, click Backup Schedule in the menu
  4. Double-clcik the data and time link for the last night’s backup
  5. Verfiy that the message shown indicated that the backup was successful
  6. Open the collapsible menu for that backup and verify that all of the selected drives and partitions were successfully backed up and that none were skipped
  7. Close the collapsible menu
  8. Click Return to Menu

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