I set up a Raspberry Pi 5 running Raspi OS with a Radxa Pentahat and two SSDs configured in RAID1 using OMV. After about 200 hours of operation, I noticed that the wear on the SSDs is quite uneven. According to the Total_LBAs_Written, one SSD (dev/sda) has around 360MB written, while the other (dev/sdb) shows about 2300MB. This isn't causing any immediate issues but I'm worried that dev/sdb will wear out faster. Is there a way to balance the write loads more evenly? Are there specific settings or options I can check to ensure the setup is functioning properly?
4 Answers
It's important to understand that RAID1 doesn't guarantee perfectly equal write distribution. Sometimes, issues like having swap on a mirrored volume can cause uneven wear. Have you checked if your swap is configured to use one of the disks? If so, consider switching to ZRAM for swap to prevent this kind of wear.
You should check the details of your RAID setup with `mdadm --details /dev/md0`. That might give you insights into how your array is performing. Also, check for hardware issues; sometimes cables or drive locations can affect writing speed, causing one drive to get more writes than the other.
Definitely run those commands to see if there's any underlying issue with the RAID configuration.
Have you thought about swapping the drives' positions? This could help identify if the issue is with the drives themselves or the setup. Also, if they continue to show uneven wear after swapping, it might hint at a deeper problem.
That's a solid idea! Testing both drives in different slots could yield useful information.
Consider running a SMART tool like `smartctl -a` on both drives. Understanding their health and wear levels could help. Remember, SSDs usually go into a read-only state well before they fail, so keep an eye on that.
Good point! Monitoring health can prevent surprises down the line.
Yeah, having swap on a RAID can definitely skew wear patterns. Using ZRAM might help keep things balanced.