1 In our testing, md raid10 is about 30% faster than megaraid's internal raid10.
3 First, let's test original configuration. It 6*1T disks and one SSD before and after bios update.
5 root@lib24:~# lsblk --scsi -m
6 NAME HCTL TYPE VENDOR MODEL REV TRAN NAME SIZE OWNER GROUP MODE
7 sdb 0:0:7:0 disk ATA INTEL SSDSC2BW24 DC32 sdb 223.6G root disk brw-rw----
8 sdc 0:2:0:0 disk DELL PERC H310 2.12 sdc 2.7T root disk brw-rw----
10 root@lib24:~# dmidecode | grep 'BIOS Rev'
13 root@lib24:~# hdparm -tT /dev/sd[bc]
16 Timing cached reads: 13750 MB in 2.00 seconds = 6890.40 MB/sec
17 Timing buffered disk reads: 950 MB in 3.00 seconds = 316.44 MB/sec
20 Timing cached reads: 13304 MB in 1.99 seconds = 6670.01 MB/sec
21 Timing buffered disk reads: 1332 MB in 3.00 seconds = 443.81 MB/sec
25 root@lib24:~# dmidecode | grep 'BIOS Rev'
27 root@lib24:~# lsblk --scsi -m
28 NAME HCTL TYPE VENDOR MODEL REV TRAN NAME SIZE OWNER GROUP MODE
29 sda 0:0:6:0 disk ATA WDC WD1002FBYS-1 0C12 sda 931.5G root disk brw-rw----
30 sdb 0:0:7:0 disk ATA INTEL SSDSC2BW24 DC32 sdb 223.6G root disk brw-rw----
31 sdc 0:2:0:0 disk DELL PERC H310 2.12 sdc 2.7T root disk brw-rw----
32 root@lib24:~# hdparm -tT /dev/sd[abc]
35 Timing cached reads: 13960 MB in 1.99 seconds = 7002.59 MB/sec
36 Timing buffered disk reads: 320 MB in 3.00 seconds = 106.57 MB/sec
39 Timing cached reads: 14004 MB in 1.99 seconds = 7024.47 MB/sec
40 Timing buffered disk reads: 962 MB in 3.00 seconds = 320.66 MB/sec
43 Timing cached reads: 13920 MB in 1.99 seconds = 6981.76 MB/sec
44 Timing buffered disk reads: 1356 MB in 3.00 seconds = 451.81 MB/sec
51 Here are steps to replace hardware megaraid with software md5 on ganeti.
56 root@lib30:/srv/gnt-info# gnt-node migrate lib28
58 root@lib30:/srv/gnt-info# gnt-node modify --drained yes lib28
60 root@lib30:/srv/gnt-info# hbal -L -X
64 This will migrate instances from node, marked it as drained and then hbal will re-distribute drbd disks
65 from it to rest of cluster.
67 Alternative is to use modify -t plain, but that requires instance reboot.
70 root@lib28:~# vgremove ffzgvg
72 root@lib28:~# pvremove /dev/bcache0
76 Then, we need to find bcache block device and deactiate it:
78 root@lib28:~# cd /sys/fs/bcache/
79 root@lib28:/sys/fs/bcache# cd 4a61e966-f18d-4fab-836a-3ff027963781/
81 root@lib28:/sys/fs/bcache/4a61e966-f18d-4fab-836a-3ff027963781# ls -al bdev0
82 lrwxrwxrwx 1 root root 0 Sep 19 19:46 bdev0 -> ../../../devices/pci0000:00/0000:00:02.2/0000:03:00.0/host0/target0:2:0/0:2:0:0/block/sdb/bcache
85 root@lib28:~# echo 1 > /sys/block/sdb/bcache/stop
86 [Wed Sep 19 20:05:53 2018] bcache: bcache_device_free() bcache0 stopped
88 root@lib28:~# megacli -CfgDsply -a0
93 root@lib28:~# megacli -CfgLdDel -L0 -a0
95 Adapter 0: Deleted Virtual Drive-0(target id-0)
100 Convert all disks to jbod
102 root@lib28:~# megacli -PDMakeJBOD -PhysDrv[32:0] -a0
104 Adapter: 0: EnclId-32 SlotId-0 state changed to JBOD.
108 root@lib28:~# megacli -PDMakeJBOD -PhysDrv[32:1] -a0
112 megacli -PDMakeJBOD -PhysDrv[32:6] -a0
114 Adapter: 0: Failed to change PD state at EnclId-32 SlotId-6.
119 This probably means that it has foreign config (makes sense, 7th disk
120 comes from another server with raid on it):
122 root@lib28:~# megacli -CfgForeign -Clear 0 -a0
124 Foreign configuration 0 is cleared on controller 0.
129 root@lib28:~# megacli -PDMakeJBOD -PhysDrv[32:6] -a0
131 Adapter: 0: EnclId-32 SlotId-6 state changed to JBOD.
136 root@lib28:~# lsblk --scsi -m
137 NAME HCTL TYPE VENDOR MODEL REV TRAN NAME SIZE OWNER GROUP MODE
138 sda 0:0:7:0 disk ATA INTEL SSDSC2BW24 DC32 sda 223.6G root disk brw-rw----
139 sdb 0:0:0:0 disk ATA ST1000NM0033-9ZM GA0A sdb 931.5G root disk brw-rw----
140 sdc 0:0:1:0 disk ATA ST1000NM0033-9ZM GA0A sdc 931.5G root disk brw-rw----
141 sdd 0:0:2:0 disk ATA ST1000NM0033-9ZM GA0A sdd 931.5G root disk brw-rw----
142 sde 0:0:3:0 disk ATA ST1000NM0033-9ZM GA0A sde 931.5G root disk brw-rw----
143 sdf 0:0:4:0 disk ATA ST1000NM0033-9ZM GA0A sdf 931.5G root disk brw-rw----
144 sdg 0:0:5:0 disk ATA ST1000NM0033-9ZM GA0A sdg 931.5G root disk brw-rw----
145 sdh 0:0:6:0 disk ATA ST1000NM0033-9ZM GA0A sdh 931.5G root disk brw-rw----
147 root@lib28:~# mdadm --create /dev/md0 --level=10 --raid-devices=7 /dev/sd{b,c,d,e,f,g,h}
148 mdadm: cannot open /dev/sdb: Device or resource busy
150 NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
151 sda 8:0 0 223.6G 0 disk
152 ├─sda1 8:1 0 260M 0 part /boot/efi
153 ├─sda2 8:2 0 10G 0 part /
154 └─sda3 8:3 0 213.3G 0 part
155 sdb 8:16 0 931.5G 0 disk
156 └─bcache0 254:0 0 931.5G 0 disk
157 sdc 8:32 0 931.5G 0 disk
158 └─bcache1 254:1 0 931.5G 0 disk
159 sdd 8:48 0 931.5G 0 disk
160 sde 8:64 0 931.5G 0 disk
161 sdf 8:80 0 931.5G 0 disk
162 sdg 8:96 0 931.5G 0 disk
163 sdh 8:112 0 931.5G 0 disk
167 root@lib28:~# wipefs /dev/sda
169 ----------------------------------------------------------------
170 0x1018 bcache [other]
171 UUID: 2dbf6232-0e89-4d7b-87c7-79897b0a34f2
173 root@lib28:~# wipefs /dev/sdb
175 ----------------------------------------------------------------
176 0x1018 bcache [other]
177 UUID: 2dbf6232-0e89-4d7b-87c7-79897b0a34f2
179 root@lib28:~# echo 1 > /sys/block/sda/bcache/stop
180 root@lib28:~# [Wed Sep 19 20:25:14 2018] bcache: bcache_device_free() bcache0 stopped
182 root@lib28:~# echo 1 > /sys/block/sdb/bcache/stop
183 root@lib28:~# [Wed Sep 19 20:25:20 2018] bcache: bcache_device_free() bcache1 stopped
186 NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
187 sda 8:0 0 931.5G 0 disk
188 sdb 8:16 0 931.5G 0 disk
189 sdc 8:32 0 931.5G 0 disk
190 sdd 8:48 0 931.5G 0 disk
191 sde 8:64 0 931.5G 0 disk
192 sdf 8:80 0 931.5G 0 disk
193 sdg 8:96 0 931.5G 0 disk
194 sdh 8:112 0 223.6G 0 disk
195 ├─sdh1 8:113 0 260M 0 part /boot/efi
196 ├─sdh2 8:114 0 10G 0 part /
197 └─sdh3 8:115 0 213.3G 0 part
199 root@lib28:~# mdadm --create /dev/md0 --level=10 --raid-devices=7 /dev/sd{a,b,c,d,e,f,g}
200 mdadm: Defaulting to version 1.2 metadata
201 mdadm: array /dev/md0 started.
205 Wait for rebuild, install bios update, reboot as needed.
207 root@lib28:~# dmidecode | grep 'BIOS Rev'
210 root@lib28:~# hdparm -Tt /dev/sdh /dev/sda /dev/md0
214 Timing cached reads: 13856 MB in 1.99 seconds = 6950.11 MB/sec
215 Timing buffered disk reads: 940 MB in 3.00 seconds = 313.22 MB/sec
219 Timing cached reads: 13722 MB in 1.99 seconds = 6883.27 MB/sec
220 Timing buffered disk reads: 572 MB in 3.01 seconds = 190.06 MB/sec
224 Timing cached reads: 13826 MB in 1.99 seconds = 6935.19 MB/sec
225 Timing buffered disk reads: 1888 MB in 3.01 seconds = 628.05 MB/sec
229 root@lib28:~# cat /proc/mdstat
230 Personalities : [raid10] [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4]
231 md127 : active (auto-read-only) raid10 sda[0] sdc[2] sdd[3] sdf[5] sdg[6] sdb[1] sde[4]
232 3418209280 blocks super 1.2 512K chunks 2 near-copies [7/7] [UUUUUUU]
233 bitmap: 0/26 pages [0KB], 65536KB chunk
235 root@lib28:~# make-bcache -B /dev/md127
236 UUID: 1c2c022b-5ed1-48d2-9ec9-499465af71a8
237 Set UUID: 83ad5994-b266-4e4b-ab6d-9be8fe419e62
241 [Thu Sep 20 02:23:12 2018] bcache: register_bdev() registered backing device md127
244 Now attach cache device back to it:
246 root@lib28:~# bcache-super-show /dev/sdh3 | grep cset.uuid
247 cset.uuid 4a61e966-f18d-4fab-836a-3ff027963781
249 root@lib28:~# echo 4a61e966-f18d-4fab-836a-3ff027963781 > /sys/block/bcache0/bcache/attach
250 [Thu Sep 20 14:18:08 2018] bcache: bch_cached_dev_attach() Caching md127 as bcache0 on set 4a61e966-f18d-4fab-836a-3ff027963781
253 Verify that bcache is active (values should NOT be all zeros if it's working):
255 root@lib28:~# grep . /sys/fs/bcache/*/stats_total/*
256 /sys/fs/bcache/4a61e966-f18d-4fab-836a-3ff027963781/stats_total/bypassed:40.8M
257 /sys/fs/bcache/4a61e966-f18d-4fab-836a-3ff027963781/stats_total/cache_bypass_hits:0
258 /sys/fs/bcache/4a61e966-f18d-4fab-836a-3ff027963781/stats_total/cache_bypass_misses:11
259 /sys/fs/bcache/4a61e966-f18d-4fab-836a-3ff027963781/stats_total/cache_hit_ratio:0
260 /sys/fs/bcache/4a61e966-f18d-4fab-836a-3ff027963781/stats_total/cache_hits:0
261 /sys/fs/bcache/4a61e966-f18d-4fab-836a-3ff027963781/stats_total/cache_miss_collisions:0
262 /sys/fs/bcache/4a61e966-f18d-4fab-836a-3ff027963781/stats_total/cache_misses:128
263 /sys/fs/bcache/4a61e966-f18d-4fab-836a-3ff027963781/stats_total/cache_readaheads:0
265 root@lib26:~# cat /sys/block/bcache0/bcache/state
269 Optionally you might want to turn on writeback mode and then state will change
271 root@lib28:~# echo writeback > /sys/block/bcache0/bcache/cache_mode
272 root@lib28:~# cat /sys/block/bcache0/bcache/state
278 root@lib28:~# pvcreate /dev/bcache0
279 Configuration setting "activation/thin_check_executable" unknown.
280 Physical volume "/dev/bcache0" successfully created.
282 root@lib28:~# vgcreate ffzgvg /dev/bcache0
283 Configuration setting "activation/thin_check_executable" unknown.
284 Volume group "ffzgvg" successfully created
287 root@lib30:~# gnt-node modify --drained no lib28
290 We should run hbal now to re-balance drbd, but we will first migrate all instances from next
291 node to upgrade to save one copy of data over cluster
293 root@lib30:~# gnt-node migrate lib24
295 root@lib30:~# gnt-node modify --drained yes lib24
297 root@lib30:~# hbal -L -X