- Add ISA-L erasure code implementation, now used automatically instead of jerasure when available
- Fix listings sending too many parallel requests to OSDs
- Fix rm-data crashing with --wait-list
- Remove empty inodes from statistics and `ls` output, after <inode_vanish_time> seconds after deletion
- Make monitor delete pool statistics when the pool is deleted and thus remove them from `df` output
- Log multiple etcd addresses in OSD logs correctly
- Fix true/false parsing in json configs like no_recovery/no_rebalance
- Show no_recovery, no_rebalance, readonly flags in status
- Add documentation! :-) in Russian and English
- Implement an NFS proxy for file-based access emulation to Vitastor
images for non-QEMU based hypervisors like VMWare, as a better way
than iSCSI
- Implement "primary affinity tags"
- Add a patch for libvirt 6.0
- Fix free_down_raw in cli status
- Fix a rare bug where OSDs could drop unrelated connections on errors
Return results and errors in a variable instead of just printing them,
separate vitastor-cli main() from cli_tool_t, move positional argument
parsing to CLI main from command implementations.
- Fix incorrect reading of extra metadata block leading to extra unknown objects in stats
- Fix CSI driver volumeMode: Block support
- Add block PVC and pod examples
- Fix build under 32 bit architectures
- Fix slow connection ramp-up caused by up_wait_retry_interval
- Implement `vitastor-cli status` (print cluster status) command
- Add a new `make-osd-hybrid.js` script to quickly prepare a lot of hybrid (HDD+SSD) OSDs
- Implement snapshot deletion for Cinder driver (only works in a healthy cluster)
- Fix a huge :) bug causing reads to return all zeroes during rebalance. Add a test to prevent it in the future
- Disconnect NBD proxy correctly without leaving a zombie [vitastor-nbd] process in D state
- Fix a rare write hang appearing with small write throttling enabled
- Создайте юниты systemd для OSD: `/usr/lib/vitastor/make-osd.sh /dev/disk/by-partuuid/XXX [/dev/disk/by-partuuid/YYY ...]`
- Вы можете менять параметры OSD в юнитах systemd или в `vitastor.conf`. Смысл некоторых параметров:
- `disable_data_fsync 1` - отключает fsync, используется с SSD с конденсаторами.
- `immediate_commit all` - используется с SSD с конденсаторами.
Внимание: если установлено, также нужно установить его в то же значение в etcd в /vitastor/config/global
- `disable_device_lock 1` - отключает блокировку файла устройства, нужно, только если вы запускаете
несколько OSD на одном блочном устройстве.
- `flusher_count 256` - "flusher" - микропоток, удаляющий старые данные из журнала.
Не волнуйтесь об этой настройке, 256 теперь достаточно практически всегда.
- `disk_alignment`, `journal_block_size`, `meta_block_size` следует установить равными размеру
внутреннего блока SSD. Это почти всегда 4096.
- `journal_no_same_sector_overwrites true` запрещает перезапись одного и того же сектора журнала подряд
много раз в процессе записи. Большинство (99%) SSD не нуждаются в данной опции. Однако выяснилось, что
диски, используемые на одном из тестовых стендов - Intel D3-S4510 - очень сильно не любят такую
перезапись, и для них была добавлена эта опция. Когда данный режим включён, также нужно поднимать
значение `journal_sector_buffer_count`, так как иначе Vitastor не хватит буферов для записи в журнал.
- Запустите все etcd: `systemctl start etcd`
- Создайте глобальную конфигурацию в etcd: `etcdctl --endpoints=... put /vitastor/config/global '{"immediate_commit":"all"}'`
(если все ваши диски - серверные с конденсаторами).
- Создайте пулы: `etcdctl --endpoints=... put /vitastor/config/pools '{"1":{"name":"testpool","scheme":"replicated","pg_size":2,"pg_minsize":1,"pg_count":256,"failure_domain":"host"}}'`.
Для jerasure EC-пулов конфигурация должна выглядеть так: `2:{"name":"ecpool","scheme":"jerasure","pg_size":4,"parity_chunks":2,"pg_minsize":2,"pg_count":256,"failure_domain":"host"}`.
- Запустите все OSD: `systemctl start vitastor.target`
- Ваш кластер должен быть готов - один из мониторов должен уже сконфигурировать PG, а OSD должны запустить их.
- Вы можете проверить состояние PG прямо в etcd: `etcdctl --endpoints=... get --prefix /vitastor/pg/state`. Все PG должны быть 'active'.
### Задать имя образу
```
etcdctl --endpoints=<etcd> put /vitastor/config/inode/<pool>/<inode> '{"name":"<name>","size":<size>[,"parent_id":<parent_inode_number>][,"readonly":true]}'
```
Например:
```
etcdctl --endpoints=http://10.115.0.10:2379/v3 put /vitastor/config/inode/1/1 '{"name":"testimg","size":2147483648}'
```
Если вы зададите parent_id, то образ станет CoW-клоном, т.е. все новые запросы записи пойдут в новый инод, а запросы
чтения будут проверять сначала его, а потом родительские слои по цепочке вверх. Чтобы случайно не перезаписать данные
в родительском слое, вы можете переключить его в режим "только чтение", добавив флаг `"readonly":true` в его запись
метаданных. В таком случае родительский образ становится просто снапшотом.
Таким образом, для создания снапшота вам нужно просто переименовать предыдущий inode (например, из testimg в testimg@0),
сделать его readonly и создать новый слой с исходным именем образа (testimg), ссылающийся на только что переименованный
- Saturated parallel write iops: min(network bandwidth, sum(disk write iops * number of data drives / (number of data + parity drives) / write amplification)).
In fact, you should put disk write iops under the condition of ~10% reads / ~90% writes in this formula.
Write amplification for 4 KB blocks is usually 3-5 in Vitastor:
1. Journal block write
2. Journal data write
3. Metadata block write
4. Another journal block write for EC/XOR setups
5. Data block write
If you manage to get an SSD which handles 512 byte blocks well (Optane?) you may
lower 1, 3 and 4 to 512 bytes (1/8 of data size) and get WA as low as 2.375.
Lazy fsync also reduces WA for parallel workloads because journal blocks are only
written when they fill up or fsync is requested.
## Example Comparison with Ceph
Hardware configuration: 4 nodes, each with:
- 6x SATA SSD Intel D3-4510 3.84 TB
- 2x Xeon Gold 6242 (16 cores @ 2.8 GHz)
- 384 GB RAM
- 1x 25 GbE network interface (Mellanox ConnectX-4 LX), connected to a Juniper QFX5200 switch
CPU powersaving was disabled. Both Vitastor and Ceph were configured with 2 OSDs per 1 SSD.
All of the results below apply to 4 KB blocks and random access (unless indicated otherwise).
Raw drive performance:
- T1Q1 write ~27000 iops (~0.037ms latency)
- T1Q1 read ~9800 iops (~0.101ms latency)
- T1Q32 write ~60000 iops
- T1Q32 read ~81700 iops
Ceph 15.2.4 (Bluestore):
- T1Q1 write ~1000 iops (~1ms latency)
- T1Q1 read ~1750 iops (~0.57ms latency)
- T8Q64 write ~100000 iops, total CPU usage by OSDs about 40 virtual cores on each node
- T8Q64 read ~480000 iops, total CPU usage by OSDs about 40 virtual cores on each node
T8Q64 tests were conducted over 8 400GB RBD images from all hosts (every host was running 2 instances of fio).
This is because Ceph has performance penalties related to running multiple clients over a single RBD image.
cephx_sign_messages was set to false during tests, RocksDB and Bluestore settings were left at defaults.
In fact, not that bad for Ceph. These servers are an example of well-balanced Ceph nodes.
However, CPU usage and I/O latency were through the roof, as usual.
Vitastor:
- T1Q1 write: 7087 iops (0.14ms latency)
- T1Q1 read: 6838 iops (0.145ms latency)
- T2Q64 write: 162000 iops, total CPU usage by OSDs about 3 virtual cores on each node
- T8Q64 read: 895000 iops, total CPU usage by OSDs about 4 virtual cores on each node
- Linear write (4M T1Q32): 2800 MB/s
- Linear read (4M T1Q32): 1500 MB/s
T8Q64 read test was conducted over 1 larger inode (3.2T) from all hosts (every host was running 2 instances of fio).
Vitastor has no performance penalties related to running multiple clients over a single inode.
If conducted from one node with all primary OSDs moved to other nodes the result was slightly lower (689000 iops),
this is because all operations resulted in network roundtrips between the client and the primary OSD.
When fio was colocated with OSDs (like in Ceph benchmarks above), 1/4 of the read workload actually
used the loopback network.
Vitastor was configured with: `--disable_data_fsync true --immediate_commit all --flusher_count 8
- Create systemd units for your OSDs: `/usr/lib/vitastor/mon/make-osd.sh /dev/disk/by-partuuid/XXX [/dev/disk/by-partuuid/YYY ...]`
- You can change OSD configuration in units or in `vitastor.conf`. Notable configuration variables:
- `disable_data_fsync 1` - only safe with server-grade drives with capacitors.
- `immediate_commit all` - use this if all your drives are server-grade.
If all OSDs have it set to all then you should also put the same value in etcd into /vitastor/config/global
- `disable_device_lock 1` - only required if you run multiple OSDs on one block device.
- `flusher_count 256` - flusher is a micro-thread that removes old data from the journal.
You don't have to worry about this parameter anymore, 256 is enough.
- `disk_alignment`, `journal_block_size`, `meta_block_size` should be set to the internal
block size of your SSDs which is 4096 on most drives.
- `journal_no_same_sector_overwrites true` prevents multiple overwrites of the same journal sector.
Most (99%) SSDs don't need this option. But Intel D3-4510 does because it doesn't like when you
overwrite the same sector twice in a short period of time. The setting forces Vitastor to never
overwrite the same journal sector twice in a row which makes D3-4510 almost happy. Not totally
happy, because overwrites of the same block can still happen in the metadata area... When this
setting is set, it is also required to raise `journal_sector_buffer_count` setting, which is the
number of dirty journal sectors that may be written to at the same time.
- `systemctl start vitastor.target` everywhere.
- Create global configuration in etcd: `etcdctl --endpoints=... put /vitastor/config/global '{"immediate_commit":"all"}'`
(if all your drives have capacitors).
- Create pool configuration in etcd: `etcdctl --endpoints=... put /vitastor/config/pools '{"1":{"name":"testpool","scheme":"replicated","pg_size":2,"pg_minsize":1,"pg_count":256,"failure_domain":"host"}}'`.
For jerasure pools the configuration should look like the following: `2:{"name":"ecpool","scheme":"jerasure","pg_size":4,"parity_chunks":2,"pg_minsize":2,"pg_count":256,"failure_domain":"host"}`.
- At this point, one of the monitors will configure PGs and OSDs will start them.
- You can check PG states with `etcdctl --endpoints=... get --prefix /vitastor/pg/state`. All PGs should become 'active'.
### Name an image
```
etcdctl --endpoints=<etcd> put /vitastor/config/inode/<pool>/<inode> '{"name":"<name>","size":<size>[,"parent_id":<parent_inode_number>][,"readonly":true]}'
```
For example:
```
etcdctl --endpoints=http://10.115.0.10:2379/v3 put /vitastor/config/inode/1/1 '{"name":"testimg","size":2147483648}'
```
If you specify parent_id the image becomes a CoW clone. I.e. all writes go to the new inode and reads first check it
and then upper layers. You can then make parent readonly by updating its entry with `"readonly":true` for safety and
basically treat it as a snapshot.
So to create a snapshot you basically rename the previous upper layer (for example from testimg to testimg@0), make it readonly
and create a new top layer with the original name (testimg) and the previous one as a parent.
huy
