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docs/tape: fix some typos and improve wording

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Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
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Dominik Csapak
2021-01-25 16:30:54 +01:00
committed by Dietmar Maurer
parent c81c46c336
commit 66d066964c
1 changed files with 14 additions and 14 deletions
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docs/tape-backup.rst
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@ -1,15 +1,15 @@
Tape Backup Tape Backup
=========== ===========
Proxmox tape backup provides an easy way to store datastore contents Proxmox tape backup provides an easy way to store datastore content
to a magnetic tapes. This increases data safety because you get: onto magnetic tapes. This increases data safety because you get:
- an additional copy of the data - an additional copy of the data
- to a different media type (tape) - to a different media type (tape)
- to an additional location (you can move tapes offsite) - to an additional location (you can move tapes offsite)
Statistics show that 95% of all restore jobs restores data from the In most restore jobs, only data from the last backup job is restored.
last backup. Restore requests further declines the older the data Restore requests further decline the older the data
gets. Considering this, tape backup may also help to reduce disk gets. Considering this, tape backup may also help to reduce disk
usage, because you can safely remove data from disk once archived on usage, because you can safely remove data from disk once archived on
tape. This is especially true if you need to keep data for several tape. This is especially true if you need to keep data for several
@ -32,14 +32,14 @@ As of 2021, the only broadly available tape technology standard is
`Linear Tape Open`_, and different vendors offers LTO Ultrium tape `Linear Tape Open`_, and different vendors offers LTO Ultrium tape
drives, autoloaders and LTO tape cartridges. drives, autoloaders and LTO tape cartridges.
Of cause, there are a few vendor offering proprietary drives with There are a few vendors offering proprietary drives with
slight advantages in performance and capacity, but they have slight advantages in performance and capacity, but they have
significat disadvantages: significant disadvantages:
- proprietary (single vendor) - proprietary (single vendor)
- a much higher purchase cost - a much higher purchase cost
So we currently do no test such drives. So we currently do not test such drives.
In general, LTO tapes offer the following advantages: In general, LTO tapes offer the following advantages:
@ -64,14 +64,14 @@ kernel should work, but feature like hardware encryptions needs LTO4
or later. or later.
Tape changer support is done using the Linux 'mtx' command line Tape changer support is done using the Linux 'mtx' command line
tool. So any changer devive supported by that tool work work. tool. So any changer device supported by that tool should work.
Drive Performance Drive Performance
~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~
Current LTO8 tapes provide read/write speeds up to 360MB/s. Please Current LTO-8 tapes provide read/write speeds up to 360MB/s. This means,
note that it still takes a minimum of 9 hours to completely write or that it still takes a minimum of 9 hours to completely write or
read a single tape (even at maximum speed). read a single tape (even at maximum speed).
The only way to speed up that data rate is to use more than one The only way to speed up that data rate is to use more than one
@ -80,10 +80,10 @@ restore jobs while the other dives are used for backups.
Also consider that you need to read data first from your datastore Also consider that you need to read data first from your datastore
(disk). But a single spinning disk is unable to deliver data at this (disk). But a single spinning disk is unable to deliver data at this
rate. We meassured a maximum rate about 60MB/s to 100MB/s in practive, rate. We measured a maximum rate of about 60MB/s to 100MB/s in practice,
so it takes 33 hours to read 12TB to fill up a LTO8 tape. If you want so it takes 33 hours to read 12TB to fill up an LTO-8 tape. If you want
to run your tape at full speed, please make sure that the source to run your tape at full speed, please make sure that the source
datastore is able to delive that performance (use SSDs). datastore is able to deliver that performance (e.g, by using SSDs).
Terminology Terminology
@ -105,7 +105,7 @@ Terminology
`Code 39`_, as definded in the `LTO Ultrium Cartridge Label `Code 39`_, as definded in the `LTO Ultrium Cartridge Label
Specification`_. Specification`_.
You can either bye such barcode labels from your cartidge vendor, You can either buy such barcode labels from your cartridge vendor,
or print them yourself. You can use our `LTO Barcode Generator`_ App or print them yourself. You can use our `LTO Barcode Generator`_ App
for that. for that.