I have a recently built Unraid server (see specs below) and want to make a change to the cache drives.  I'd built the cache with two 2tb 7.2k SAS drives as a pool, which is entirely too slow... I'm also finding I don't really need 2tb of cache space.  My primary use for this server is Plex and my 3CX phone system.

 

I'd like to replace the cache drives with two pooled 1TB SSD drives.  Questions and possible issue I need clarity on;

 

1. What is the preferred method to replace cache drives with smaller capacity replacements?
2. The 8 drive slots on my T710 are all occupied - two 2TB SAS cache drives and six 6TB SAS drives (no room/slots/channels to add more SAS/SATA drives).  Since the drives are pooled, I understand I could pull one and rebuild on a new drive, but can this be done on a smaller drive?
3. If migrating/rebuilding to smaller drives is risky or overly complicated, I assume I can follow other documented processes to replace with (much more expensive) 2TB SSD drives one at a time?

 

Config:

• Unraid 6.9.2
• Dell T710 II w/ two x5690 CPU’s
• 96GB Ram
• Dual 1100 watt PS
• Nvidia Quadro P2000 video card for transcoding (love the T710 for this easy install as opposed to the R710)
• Dell H310 – IT Mode
• (6) Hitachi HUS726060AL5210 6TB SAS Drives
• (2) Hitachi HUS723020ALS640 2TB 6G SAS Drives (Cache)
• Dell / Intel XYT17 / X520-DA2 10GB FH Network Adapter (not configured)
• 4 network ports on T710 running as bonded, active-backup, 1gb
• Dedicated APC 1500va UPS

 

Thanks all!

Edited June 14, 20215 yr by mproberts
Resolved

You can't directly replace with smaller devices, you could add new members and then remove the other ones, but if I understood correctly you don't have enough ports, in that case you could follow this to backup cache to array, replace pool, then restore data.

Got it - thank you.  This helps.