Changes for page Ceph

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...	...	@@ -53,6 +53,7 @@
53	53
54	54	Now you have a raw storage device, but you can't yet store files on it, since you are missing a filesystem.
55	55
	56	+
56	56	## RBD formatting
57	57
58	58	Now that you have mapped your RBD, we can create file system structures on it.
...	...	@@ -64,7 +64,6 @@
64	64	```
65	65
66	66	get the newly created filesystem UUID:
67		-
68	68	```
69	69	sudo blkid /dev/rbdxxx
70	70	```
...	...	@@ -72,7 +72,6 @@
72	72	Now we create an entry in `/etc/fstab` with `noauto` so the below script triggers the mount, and the mount is not done too early in the boot.
73	73
74	74	`/etc/fstab`:
75		-
76	76	```
77	77	UUID=your-new-fs-uuid /your/mount/point ext4 defaults,_netdev,acl,noauto,nodev,nosuid,noatime,stripe=1024 0 0
78	78	```
...	...	@@ -80,7 +80,6 @@
80	80	In order to mount this filesystem in your server, we need a mount helper script (otherwise the RBD is not yet mapped on system start when `/etc/fstab` tries to mount it directly during boot).
81	81
82	82	`/etc/ceph/rbd.d/ORG-rbd/namespacename/rbdname`:
83		-
84	84	```bash
85	85	#!/bin/bash
86	86
...	...	@@ -91,15 +91,17 @@
91	91	# mount all the filesystems
92	92	mountpoint -q /your/mount/point || mount /your/mount/point
93	93	```
	92	+Mark this script *executable* so `rbdmap` can execute it as post-mapping hook!
94	94
95		-Mark this script _executable_ so `rbdmap` can execute it as post-mapping hook!
96		-
97	97	To test, either restart `rbdmap.service` or manually call `umount` and `mount` for `/your/mount/point`.
98	98
	96	+
99	99	## LVM on RBD
100	100
101		-You can create LVM `pvs` and `lvs` on your RBD. You can use this for read/write caching, for example (see below). This works like usual, just do `pvcreate` etc.
	99	+You can create LVM `pvs` and `lvs` on your RBD. You can use this for read/write caching, for example (see below).
	100	+This works like usual, just do `pvcreate` etc.
102	102
	102	+
103	103	## RBD tuning
104	104
105	105	To get more performance, there's some useful tweaks
...	...	@@ -109,7 +109,6 @@
109	109	When your server is sufficiently shielded behind firewalls and it isn't susceptible to attacks, disable the cpu bug mitigations for a performance boost as a kernel command line parameter:
110	110
111	111	`/etc/default/grub`:
112		-
113	113	```
114	114	GRUB_CMDLINE_LINUX_DEFAULT="mitigations=off"
115	115	```
...	...	@@ -116,10 +116,9 @@
116	116
117	117	### Read-Ahead
118	118
119		-We read ahead 1MiB, since Ceph stores the objects in 4MiB blocks anyway. We also allow more parallel requests and use no IO scheduler (since Ceph is distributed with equal latency anyway).
	118	+We read ahead 1MiB, since Ceph stores the objects in 4MiB blocks anyway.
120	120
121	121	`/etc/udev/rules.d/90-ceph-rbd.rules`:
122		-
123	123	```
124	124	KERNEL=="rbd[0-9]*", ENV{DEVTYPE}=="disk", ACTION=="add|change", ATTR{bdi/read_ahead_kb}="1024" ATTR{queue/scheduler}="none" ATTR{queue/wbt_lat_usec}="0" ATTR{queue/nr_requests}="2048"
125	125	```
...	...	@@ -126,11 +126,12 @@
126	126
127	127	### LVM-Cache
128	128
129		-see `man 7 lvmcache`. We can cache the RBD on a local NVMe for more performance.
	127	+see `man 7 lvmcache`.
	128	+We can cache the RBD on a local NVMe for more performance.
130	130
131	131	* `/dev/fastdevice` is the name of the local NVMe.
132	132	* `/dev/datavg/datalv` is your name of your existing logical volume containing all the stored data on Ceph.
133		-* we recommend read and write caching, and a local fastdevice size of at least 50GiB. the more the better :)
	132	+* we recommend writeback caching
134	134
135	135	```bash
136	136	## setup
...	...	@@ -175,11 +175,3 @@
175	175	# remove pv from vg
176	176	lvreduce datavg /dev/fastdevice
177	177	```
178		-
179		-### NFS tuning
180		-
181		-in /etc/default/nfs-kernel-server:
182		-```
183		-echo "1048576" > /proc/fs/nfsd/max_block_size # allow 1MiB iosize (geht auch noch mehr)
184		-RPCNFSDCOUNT=64 # workeranzahl
185		-```