Difference between revisions of "CT storage backends"
Narcisgarcia (talk | contribs) (Reorganization, deduplication, +LVM +ZFS) |
Narcisgarcia (talk | contribs) (References, vzctl integration) |
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= Comparison tables = | = Comparison tables = | ||
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=== Solidity in front of failures and security === | === Solidity in front of failures and security === | ||
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{| class="wikitable sortable" style="text-align: center;" | {| class="wikitable sortable" style="text-align: center;" | ||
! Feature | ! Feature | ||
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|'''I/O isolation''' | |'''I/O isolation''' | ||
|{{Yes|Good}} | |{{Yes|Good}} | ||
| − | |{{No|Bad}}: Some bug could be exploited to escape CT and access HN file system | + | |{{No|Bad}}: Some bug could be exploited to escape CT and access HN file system <ref>[https://bugs.openvz.org/browse/OVZ-6296 CVE-2015-2925]</ref> <ref>[http://www.openwall.com/lists/oss-security/2014/06/24/16 CVE-2014-3519]</ref> |
|{{Yes|Good}} | |{{Yes|Good}} | ||
|{{Yes|Good}} | |{{Yes|Good}} | ||
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|{{Yes|Since 1998}} | |{{Yes|Since 1998}} | ||
|{{No|Since 2014}} | |{{No|Since 2014}} | ||
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| − | |||
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| − | |||
| − | |||
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|- | |- | ||
|} | |} | ||
=== Performance and design features === | === Performance and design features === | ||
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{| class="wikitable sortable" style="text-align: center;" | {| class="wikitable sortable" style="text-align: center;" | ||
! Feature | ! Feature | ||
| Line 61: | Line 54: | ||
|'''Maximum container volume space''' | |'''Maximum container volume space''' | ||
|4 TiB <ref>[[Ploop/Limits]]</ref> | |4 TiB <ref>[[Ploop/Limits]]</ref> | ||
| − | |1 EiB | + | |1 EiB <ref>[https://en.wikipedia.org/wiki/Ext4 Ext4]</ref> |
| − | | | + | |? |
|256 ZiB | |256 ZiB | ||
|- | |- | ||
| Line 100: | Line 93: | ||
|{{No}} | |{{No}} | ||
|No | |No | ||
| + | |- | ||
| + | |'''Incremental backup support on filesystem level''' | ||
| + | |{{Yes}}, through snapshots | ||
| + | |{{No}} | ||
| + | |{{No}} | ||
| + | |{{Yes}} | ||
|- | |- | ||
|} | |} | ||
=== Administrator operations === | === Administrator operations === | ||
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{| class="wikitable sortable" style="text-align: center;" | {| class="wikitable sortable" style="text-align: center;" | ||
! Feature | ! Feature | ||
| Line 111: | Line 109: | ||
! LVM (ext4) | ! LVM (ext4) | ||
! ZFS (~simfs) | ! ZFS (~simfs) | ||
| + | |- | ||
| + | |'''vzctl integration''' | ||
| + | |{{Yes|Complete}} | ||
| + | |{{Yes|Complete}} | ||
| + | |{{No|No}}, many manual operations | ||
| + | |{{Yes|No}}, some manual operations | ||
|- | |- | ||
|'''External compaction for container volumes''' | |'''External compaction for container volumes''' | ||
| Line 125: | Line 129: | ||
|- | |- | ||
|'''Live backup''' | |'''Live backup''' | ||
| − | |{{Yes|Easy, fast and consistent}}<ref | + | |{{Yes|Easy, fast and consistent}}<ref>[http://openvz.livejournal.com/44508.html ploop snapshots and backups]</ref> <ref>[[Ploop/Backup]]</ref> |
|{{No|Easy, slow, and sometimes inconsistent}} in case some application depends on inode IDs | |{{No|Easy, slow, and sometimes inconsistent}} in case some application depends on inode IDs | ||
|{{No|Fast}} | |{{No|Fast}} | ||
| Line 131: | Line 135: | ||
|- | |- | ||
|'''Snapshot support''' | |'''Snapshot support''' | ||
| − | |{{Yes}}<ref | + | |{{Yes}}<ref>[http://openvz.livejournal.com/44508.html ploop snapshots and backups]</ref> |
|{{No}} theoretically, because of much/small files to be copied | |{{No}} theoretically, because of much/small files to be copied | ||
|{{Yes}} | |{{Yes}} | ||
Revision as of 13:16, 6 June 2016
This article is a stub. You can help OpenVZ Wiki by expanding it. <translate>
Contents
Comparison tables
Solidity in front of failures and security
| Feature | OVZ Ploop | OVZ SimFS (ext4) | LVM (ext4) | ZFS (~simfs) |
|---|---|---|---|---|
| I/O isolation | Good | Bad: Some bug could be exploited to escape CT and access HN file system [1] [2] | Good | Good |
| Reliability | Low: big amount of files produce ext4 corruption so often | Medium: fsck, power loss and HW Raid without cache can kill whole data | High: LVM metadata can be corrupted completely | Excellent: no write hole, checksumming and COW |
| Risk to be using filesystem over filesystem | Yes | No | No | ? |
| Effect of HN filesystem corruption at /vz | No effect | Same FS | ? | ? |
| Maturity in O/VZ | Since 2012 | Since ~2005 | Since 1998 | Since 2014 |
Performance and design features
| Feature | OVZ Ploop | OVZ SimFS (ext4) | LVM (ext4) | ZFS (~simfs) |
|---|---|---|---|---|
| Maximum container volume space | 4 TiB [3] | 1 EiB [4] | ? | 256 ZiB |
| Wasted space due to architecture | up to 20% | No | up to 20% | ? |
| Disk i/o speed | Fast in any case | Very fast with small amount of containers | Fast in any case | Fast in any case |
| Disk space overcommit (provide more space for containers than available on server now) | Yes | Yes | No | Yes |
| Different containers may use file systems of different types and properties | Yes | No | Yes | No |
| Second level quotes in Linux (inside container) | Yes | Yes | Yes | Not implemented |
| Potential support for QCOW2 and other image formats | Yes | No | No | No |
| Incremental backup support on filesystem level | Yes, through snapshots | No | No | Yes |
Administrator operations
| Feature | OVZ Ploop | OVZ SimFS (ext4) | LVM (ext4) | ZFS (~simfs) |
|---|---|---|---|---|
| vzctl integration | Complete | Complete | No, many manual operations | No, some manual operations |
| External compaction for container volumes | Needed for saving HN space | No | Not available | Not required |
| Access to private area from host | Yes | Yes | ? | ? |
| Live backup | Easy, fast and consistent[5] [6] | Easy, slow, and sometimes inconsistent in case some application depends on inode IDs | Fast | Fast theoretically |
| Snapshot support | Yes[7] | No theoretically, because of much/small files to be copied | Yes | Yes |
| Live migration | Reliable and fast | Not reliable and slow, if some application depends on inode IDs | Not implemented | Fast theoretically |
| Continue failed CT migration | Yes, in vzctl from OpenVZ -stable | Yes, option "--keep-dst" | Not implemented | ? |
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