@cryptotaxi247 / netdata-1 / commits / a1125c8c9

Update BTRFS chart descriptions.

This adds some info on what the values in the graphs should ideally look like, and a bit on how to keep them that way, namely: * Suggest some degree of slack space that should be present in the physical usage chart. The particular 5% reference is based on my own experience. Also refers to `btrfs balance` as the way to help keep things that way, with a reference to the man page for the balance command. * Suggestions for data and metadata are based on the ideal standard of having no more than one chunk partially full (Data chunks are nominally 1-5GB, metadata are nominally 256MB to 1GB, but need more slack space to account for the Global Reserve). * The info added for system chunks gives descriptions of expected behavior only. The system chunks only store the tree that tracks the locations of chunk allocations on the FS, so they are generally not an issue (16K of space here holds enough room for approximately 663 chunks to be tracked, which translates to roughly 500 GB of allocated space). * I've also removed references to RAID in the descriptions. Strictly speaking, BTRFS replication and striping are _not_ RAID, and there's been a lot of noise recently on the BTRFS mailing list regarding this and the confusion the profile naming has caused, so I would suggest not referring to things as RAID.

Austin S. Hemmelgarn committed Dec 20, 2017 at 09:07 UTC a1125c8c9de993648e82071692b022053da9ed17

1 file changed +4 -4

web/dashboard_info.js

+4 -4

@@ -1670,18 +1670,18 @@ netdataDashboard.context = {

1670 },

1671

1672 'btrfs.disk': {

1673 - info: 'Physical disk usage of BTRFS. The disk space reported here, is the raw physical disk space assigned to the BTRFS volume (i.e. <b>before any RAID levels</b>). BTRFS uses a two-stage allocator, first allocating large regions of disk space for one type of block (data, metadata, or system), and then using a regular block allocator inside those regions. <code>unallocated</code> is the physical disk space that is not allocated yet and is available to become data, metdata or system on demand. When <code>unallocated</code> is zero, all available disk space has been allocated to a specific function.'

1673 + info: 'Physical disk usage of BTRFS. The disk space reported here is the raw physical disk space assigned to the BTRFS volume (i.e. <b>before any RAID levels</b>). BTRFS uses a two-stage allocator, first allocating large regions of disk space for one type of block (data, metadata, or system), and then using a regular block allocator inside those regions. <code>unallocated</code> is the physical disk space that is not allocated yet and is available to become data, metdata or system on demand. When <code>unallocated</code> is zero, all available disk space has been allocated to a specific function. Healthy volumes should ideally have at least five percent of their total space <code>unallocated/<code>. You can keep your volume healthy by running the <code>btrfs balance</code> command on it regularly (check <code>man btrfs-balance</code> for more info).'

1674 },

1675

1676 'btrfs.data': {

1677 - info: 'Logical disk usage for BTRFS data. The disk space reported here is the usable allocation (i.e. after any RAID levels).'

1677 + info: 'Logical disk usage for BTRFS data. The disk space reported here is the usable allocation (i.e. after any striping or replication). Healthy volumes should ideally have no more than a few GB of free space reported here persistently. Running <code>btrfs balance</code> can help here.'

1678 },

1679

1680 'btrfs.metadata': {

1681 - info: 'Logical disk usage for BTRFS metadata. The disk space reported here is the usable allocation (i.e. after any RAID levels).'

1681 + info: 'Logical disk usage for BTRFS metadata. The disk space reported here is the usable allocation (i.e. after any striping or replication). Healthy volumes should ideally have no more than a few GB of free space reported here persistently. Running <code>btrfs balance</code> can help here.'

1682 },

1683

1684 'btrfs.system': {

1685 - info: 'Logical disk usage for BTRFS system. The disk space reported here is the usable allocation (i.e. after any RAID levels).'

1685 + info: 'Logical disk usage for BTRFS system. The disk space reported here is the usable allocation (i.e. after any striping or replication). The values reported here should be relatively small compared to Data and Metadata, and will scale with the volume size and overall space usage.'

1686 }

1687 };