Event ID 1077: Storage Threshold Exceeded - Fix Guide 2025

Event ID: 1077
Source: MSExchangeIS
Level: Warning

The disk space on volume D:\ has fallen below the threshold.

Current free space: 8.2 GB
Recommended free space: 10 GB

Database: Mailbox Database 01
Status: Running (will dismount if space falls below 200 MB)

Action required: Free up disk space immediately to prevent
automatic database dismount and service disruption.

# Check free space on all drives
Get-PSDrive -PSProvider FileSystem |
    Select-Object Name, @{N="Free(GB)";E={[math]::Round($_.Free/1GB,2)}},
                  @{N="Used(GB)";E={[math]::Round($_.Used/1GB,2)}},
                  @{N="Total(GB)";E={[math]::Round(($_.Free+$_.Used)/1GB,2)}},
                  @{N="Free%";E={[math]::Round($_.Free/($_.Free+$_.Used)*100,2)}} |
    Format-Table -AutoSize

# Identify which databases are on low-space drives
Get-MailboxDatabase -Server $env:COMPUTERNAME |
    Format-Table Name, EdbFilePath, LogFolderPath -AutoSize

# Check transaction log accumulation (biggest quick win)
$Databases = Get-MailboxDatabase -Server $env:COMPUTERNAME
foreach ($DB in $Databases) {
    $LogPath = $DB.LogFolderPath.PathName
    $LogFiles = Get-ChildItem $LogPath -Filter "*.log"
    $LogSize = ($LogFiles | Measure-Object -Property Length -Sum).Sum / 1GB

    Write-Host "Database: $($DB.Name)" -ForegroundColor Cyan
    Write-Host "  Log Path: $LogPath"
    Write-Host "  Log Files: $($LogFiles.Count)"
    Write-Host "  Total Log Size: $([math]::Round($LogSize, 2)) GB"2)) GB" -ForegroundColor Yellow
}

# Full backup commits transaction logs and allows Exchange to truncate them
# This typically reclaims 10-50 GB immediately in production environments-50 GB immediately in production environments

# If using Windows Server Backup:
wbadmin start backup -backupTarget:E: -include:D: -quiet

# If using third-party backup (Veeam, Acronis, etc):
# Trigger immediate full backup via backup console

# After backup completes, verify log truncation occurred
Start-Sleep -Seconds 300  # Wait 5 minutes for backup completion

# Check if logs were truncated (old logs should be deleted)
$Databases = Get-MailboxDatabase -Server $env:COMPUTERNAME
foreach ($DB in $Databases) {
    $LogPath = $DB.LogFolderPath.PathName
    $LogFiles = Get-ChildItem $LogPath -Filter "*.log"

    Write-Host "Database: $($DB.Name)" -ForegroundColor Cyan
    Write-Host "  Remaining log files: $($LogFiles.Count)"
    Write-Host "  Size: $([math]::Round(($LogFiles | Measure-Object Length -Sum).Sum / 1GB, 2)) GB"-Object Length -Sum).Sum / 1GB, 2)) GB"
}

# If logs were NOT truncated, check last backup status
Get-MailboxDatabase | Format-Table Name, LastFullBackup, LastIncrementalBackup

# If backups are failing or unavailable, reclaim space from other sources

# 1. Clear IIS logs (often 5-20 GB)5-20 GB)
$IISLogPath = "C:\inetpub\logs\LogFiles"
if (Test-Path $IISLogPath) {
    Get-ChildItem $IISLogPath -Recurse -Filter "*.log" |
        Where-Object { $_.LastWriteTime -lt (Get-Date).AddDays(-30) } |
        Remove-Item -Force -Verbose
}

# 2. Clear Windows Update cache
Stop-Service wuauserv -Force
Remove-Item "C:\Windows\SoftwareDistribution\Download\*" -Recurse -Force -ErrorAction SilentlyContinue
Start-Service wuauserv

# 3. Clear temp files
Remove-Item "$env:TEMP\*" -Recurse -Force -ErrorAction SilentlyContinue
Remove-Item "C:\Windows\Temp\*" -Recurse -Force -ErrorAction SilentlyContinue

# 4. Clear old Windows event logs (if log drive is full)
wevtutil el | ForEach-Object { wevtutil cl $_ }

# 5. Check for orphaned database files
$AllDBPaths = Get-MailboxDatabase | Select-Object -ExpandProperty EdbFilePath
Get-ChildItem "D:\ExchangeDBs" -Filter "*.edb" -Recurse | Where-Object {
    $_.FullName -notin $AllDBPaths.PathName
} | Select-Object FullName, @{N="Size(GB)";E={[math]::Round($_.Length/1GB,2)}}

# WARNING: Only delete orphaned .edb files if you're CERTAIN they're not needed!

# Check current free space after cleanup
Get-PSDrive D | Select-Object Name,
    @{N="Free(GB)";E={[math]::Round($_.Free/1GB,2)}},
    @{N="Free%";E={[math]::Round($_.Free/($_.Free+$_.Used)*100,2)}}

# If free space is now >10 GB, crisis averted
# If still <10 GB, proceed to Advanced Troubleshooting for emergency options

# 1. Verify free space is above warning threshold
Get-PSDrive -PSProvider FileSystem |
    Where-Object { $_.Name -in @('D','E','F') } |
    Select-Object Name,
        @{N="Free(GB)";E={[math]::Round($_.Free/1GB,2)}},
        @{N="Free%";E={[math]::Round($_.Free/($_.Free+$_.Used)*100,2)}} |
    Format-Table -AutoSize

# All database/log drives should show >10 GB free and >20% free space20% free space

# 2. Verify transaction log counts are normal
$Databases = Get-MailboxDatabase -Server $env:COMPUTERNAME
foreach ($DB in $Databases) {
    $LogPath = $DB.LogFolderPath.PathName
    $LogCount = (Get-ChildItem $LogPath -Filter "*.log").Count

    if ($LogCount -lt 50) {
        Write-Host "✓ $($DB.Name): $LogCount logs (Normal)"$LogCount logs (Normal)" -ForegroundColor Green
    } else {
        Write-Host "⚠ $($DB.Name): $LogCount logs (High - check backups)"$LogCount logs (High - check backups)" -ForegroundColor Yellow
    }
}

# 3. Check Event Viewer for resolution
Get-EventLog -LogName Application -Source MSExchangeIS -After (Get-Date).AddHours(-2) |
    Where-Object { $_.EventID -eq 1077 } |
    Measure-Object
# Count should be 0 (no new Event 1077 warnings)1077 warnings)

# 4. Verify backups are completing successfully
Get-MailboxDatabase |
    Format-Table Name, LastFullBackup, LastIncrementalBackup, CircularLoggingEnabled -AutoSize

# LastFullBackup should be within last 24 hours

# 5. Test database operations are not throttled
Get-MailboxDatabase |
    Select-Object Name, @{N="BackgroundDatabaseMaintenance";E={$_.BackgroundDatabaseMaintenance}} |
    Format-Table -AutoSize

# 6. Monitor space for 24 hours to ensure stability24 hours to ensure stability
# Space should remain stable or decrease slightly (after backup log truncation)

# Save as Monitor-ExchangeDiskSpace.ps1
# Schedule with Task Scheduler to run every 4 hours

$Threshold_Warning = 25  # Alert at 25% free
$Threshold_Critical = 15 # Critical alert at 15% free
$Results = @()

# Check all volumes hosting Exchange databases
$Databases = Get-MailboxDatabase -Server $env:COMPUTERNAME
$Volumes = $Databases | ForEach-Object {
    $_.EdbFilePath.PathName.Substring(0,2)
    $_.LogFolderPath.PathName.Substring(0,2)
} | Select-Object -Unique

foreach ($Volume in $Volumes) {
    $Drive = Get-PSDrive $Volume.TrimEnd(':')
    $FreePercent = [math]::Round(($Drive.Free / ($Drive.Free + $Drive.Used)) * 100, 2)
    $FreeGB = [math]::Round($Drive.Free / 1GB, 2)

    if ($FreePercent -lt $Threshold_Critical) {
        $Results += "CRITICAL: Volume $($Volume) has only $FreePercent% free ($FreeGB GB)"$FreePercent% free ($FreeGB GB)"
    } elseif ($FreePercent -lt $Threshold_Warning) {
        $Results += "WARNING: Volume $($Volume) has $FreePercent% free ($FreeGB GB)"$FreePercent% free ($FreeGB GB)"
    }
}

# Check transaction log counts
foreach ($DB in $Databases) {
    $LogPath = $DB.LogFolderPath.PathName
    $LogCount = (Get-ChildItem $LogPath -Filter "*.log" -ErrorAction SilentlyContinue).Count

    if ($LogCount -gt 100) {
        $Results += "WARNING: $($DB.Name) has $LogCount transaction logs (possible backup issue)"$LogCount transaction logs (possible backup issue)"
    }
}

# Check last backup times
foreach ($DB in $Databases) {
    $LastBackup = $DB.LastFullBackup
    if (-not $LastBackup -or $LastBackup -lt (Get-Date).AddDays(-2)) {
        $Results += "CRITICAL: $($DB.Name) last backup was $(if($LastBackup){"$LastBackup){"$LastBackup"}else{"NEVER"})"
    }
}

# Send alert if issues found
if ($Results.Count -gt 0) {
    $Body = "Exchange Disk Space Alert:\n\n" + ($Results -join "\n")
    Send-MailMessage \
        -To "admin@company.com" \
        -From "exchange-monitor@company.com" \
        -Subject "Exchange Disk Space Alert - $($Results.Count) Issues" \
        -Body $Body \
        -SmtpServer "smtp.company.com" \
        -Priority High
} else {
    Write-Host "✓ All disk space checks passed" -ForegroundColor Green
}