Server Troubleshooting

Boot Errors

Misconfigured RAID array

Drive failure

Controller or HBA failure

Loose connections or cable failures

Corrupt boot sector

Corrupt file system table

Backplane failure

OS not found

Drive failure

Controller or HBA failure

Corrupt boot sector

Boot loader misconfiguration

Corrupt file system table

Sector block errors

Drive failure

Bad sectors

Read-write errors

Drive failure

Bad sectors

Controller or HBA failure

Loose connections or cable failures

Failed drives/failed multiple drives

Drive failure

Array rebuild

Misconfigured RAID array

Controller or HBA failure

Mismatched drives

Slow access/slow IO

Disk space utilization

Insufficient disk space

Misconfigured RAID

Array rebuild

Drive failure

Controller or HBA failure

Loose connections or cable failures

Backplane failure

Cache failure

Cache battery failure on RAID array

Cache turned off

Virtual memory configurations

Disk space utilization

Insufficient disk space

Misconfigured page/swap/scratch file or partition

Partition errors

Improper disk partition

Misconfiguration in OS

Unable to mount partitions or logical drives

Misconfiguration in OS

Improper RAID configuration

Unable to mount physical drive

Drive failure

Misconfigured RAID array

Controller or HBA failure

Loss of data on a RAID array

Cache battery failure

Misconfigured RAID

Array rebuild

HBA failure

Drive failure

Failed backups

Media failure

Drive failure

Misconfiguration in backup software

Failed restorals

Media failure

Drive failure

Misconfiguration in backup software

Unable to log on

Server not joined to domain

Clock skew

User error

Unable to access resources or files

Incompatible drivers/modules

Unstable drivers or software

Server not joined to domain

Inappropriate application-level permissions

System file corruption

Incompatible drivers/modules

Improperly applied patches

Missing or failed patches

Missing dependencies

Memory leak

Buffer overrun

Missing updates

End of life

Incompatibility due to dependencies or version control

Slow performance

Incompatible or missing drivers/modules

Improperly applied or failed patches

Memory leaks

Buffer overrun

Improper CPU affinity/priority

Cannot write to system logs

Inappropriate application-level permissions

Architecture

Server not joined to domain

Service failures

Missing dependencies

Insecure dependencies

Missing updates

System or application hanging or freezing

Incompatible drivers/modules

Improperly applied patches

Downstream failure due to updates

Cannot install OS or applications

Incompatible architecture

Patch update failure

Improperly applied patches

Incompatible architecture

Missing dependencies

Insecure dependencies

No Internet connectivity

Improper IP configuration

Component failures

Firewall misconfiguration

DNS failure

Misconfigured edge router

Failure of service provider

Bad cables

Resource unavailable

Improper IPv4 or IPv6 configuration due to a DHCP misconfiguration or failure

Improper IPv4 or IPv6 configuration due to a static IP assignment mistake

VLAN misconfiguration

Network port security misconfigured at the switch

Cable failure

Firewall misconfiguration

NIC misconfiguration

DNS failure

DNS/hosts file misconfiguration

Receiving incorrect or no DHCP information

DHCP service failure or disabled

DHCP service misconfiguration

DHCP server out of IP addresses

DHCP server not authorized in Active Directory

DHCP server on the other side of router from clients

Ping failures

"Destination host unreachable" is usually a misconfiguration of the ping sender.

"Unknown host" may be a name resolution issue

"Timeout" is usually a misconfiguration of the ping destination.

Unable to reach remote subnets

Router misconfigured

OS route tables misconfigured

Router failure

Failed name resolution

Improper IPv4 or IPv6 configuration

Misconfigured or failed DNS

Misconfigured hosts file

DNS server failure

Unknown host

File integrity

Misconfigured permissions

Viruses

Malware

Improper privilege escalation (excessive access)

Misconfigured Local/Group Policy settings

Misconfigured permissions

Applications won't load

Misconfigured services

Misconfigured anti-malware

Misconfigured Local/Group Policy settings

Misconfigured permissions

Zombie/orphan processes

Cannot access network shares

Misconfigured services

Misconfigured anti-malware

Misconfigured Local/Group Policy settings

Misconfigured permissions

Misconfigured data loss prevention tools

Misconfigured intrusion detection systems

Unable to open files

Misconfigured services

Misconfigured anti-malware

Misconfigured Local/Group Policy settings

Misconfigured permissions

Misconfigured data loss prevention tools

Misconfigured intrusion detection systems