Since your MagStor M2000 contains an IBM ULTRIUM-HH8 (LTO-8) drive, it uses a standard LTO Ultrium Universal Cleaning Cartridge. You do not need a MagStor-specific cleaning tape. The drive accepts the same universal cleaning cartridges used across IBM, HPE, Quantum, and other LTO libraries. MagStor¹⁾

The following are all appropriate choices:

HPE LTO Ultrium Universal Cleaning Cartridge (C7978A)

$49.99

This is sold by MagStor themselves and is fully compatible with the M2000. MagStor²⁾

Other equally compatible options include:

IBM LTO Ultrium Universal Cleaning Cartridge (35L2086)

$50.83

Fujifilm LTO Ultrium Universal Cleaning Cartridge (600004292)

$49.50

These are all universal LTO cleaning cartridges and will clean your IBM LTO-8 drive. MagStor³⁾

An IBM LTO Universal Cleaning Cartridge is rated for up to 50 cleaning cycles. After the 50th use, the drive recognizes it as expired and automatically ejects it. IBM specifically recommends replacing it at that point because continued use can actually deposit debris back onto the heads. ibm.com⁴⁾

For modern LTO drives, no.

The IBM LTO-8 drive monitors its own read/write error rates and requests cleaning only when necessary. Routine scheduled cleaning is not recommended because cleaning media is mildly abrasive and unnecessary cleaning shortens head life. ibm.com⁵⁾

If you leave the cleaning cartridge in one of the library slots:

• Label it with a barcode beginning with CLN (for example, CLN001L8).
• The library recognizes it as a cleaning cartridge rather than a data cartridge.
• When the IBM drive requests cleaning, the library can automatically load the cleaning cartridge if your backup software and library are configured for automatic cleaning. ibm.com⁶⁾

Since you're running:

• MagStor M2000
• IBM LTO-8 HH SAS drive
• Archiware P5 on Linux

I would purchase one universal cleaning cartridge and keep it permanently in the library. The IBM 35L2086 or the HPE C7978A are my preferred choices because they are widely available and have an excellent track record. In practice, there is no functional difference between the IBM, HPE, and Fujifilm universal cleaning cartridges for your drive.