SEP sesam allows you to set additional (advanced) backup and restore options that apply to different task types, e.g., VMware vSphere, MySQL, etc. You can set additional backup or restore options in their properties or when creating a new backup and restore task. You can create a restore task using the GUI restore wizard or via the web interface Restore Assistant.
Setting advanced options in GUI and Web UI
- You can set additional options for backup or restore in the backup task properties: from Main Selection -> Tasks by Clients -> click New Backup Task or double-click the corresponding backup task to open its properties. Under the Options tab -> Additional call arguments -> add your backup or restore option to the Backup options or Restore options field, respectively.
- Restore via the web interface
- Additional restore options are available in the advanced UI mode. In the startup window, you can select additional restore types, such as restoring backups and VMs to the file system, writing backups and VMs to dump files, restoring a single file from a VM, performing VMware sandbox restore, and so on. An additional Options tab is available for all task types. For details, see the web interface Restore Assistant.
- Restore via GUI
- You can use the restore wizard to set additional restore options: From Target Settings (fourth step of the restore wizard), under the Expert Options -> Options tab -> Restore options. For details, see Expert Options.
|The Expert Options button for setting advanced restore options is available only in advanced mode (formerly expert GUI mode). If you cannot see the Expert Options, change simple UI mode (formerly basic GUI mode) to advanced, as described in Selecting UI mode.
A VMware VM consists of data that is stored in a single disk file – the Virtual Machine Disk (VMDK) file format; it stores the entire contents of the VM's hard disk drive. Each VM can have one or more .vmdk files, which means that a VM can contain multiple VMDK files (or hard disk drives). The number of .vmdk files depends on the size of the virtual disk. VMDKs can be provisioned in three different formats: Thin, Lazy Zero Thick (flat) or Eager Zero Thick. To improve restore performance, you might want to change the provisioning method for restore.
When restoring a VMware VM, the VM's virtual disks are restored with the original provisioning used at the time of backup. You can force a different disk provisioning method: thin, eager or lazy, which is applied to all restored VMDKs by entering the following command in the restore options field:
If set, this option overrides the VMDK disk type of all VMDKs for VM restore.
Linux Client backup
SEP sesam Linux Client may encounter errors or warnings
A SEP sesam Linux Client may encounter errors or warnings during backup for the following reasons:
- the size of a file has changed during the backup
- a file is deleted during the backup (between 'find' and data processing)
- the 'find' function has encountered an error
To avoid these warnings and fix the above errors, double-click the backup task to open its properties and under the Options tab in the Backup options field enter the following command:
|You can use a regular expression (see Examples for Excluding Matched Patterns) or 'ALL' if you want to avoid all such errors/warnings.
The exclude list for Linux Client backup can also be used as an include list
When specifying the exclude list on SEP sesam Linux Client, it is possible to change the exclude to an include filter by using the + (plus) sign at the beginning of a pattern. In this case, only the items that match the defined pattern (regex) are included in the backup.
The easiest way to turn the exclude list to an include list is to use the GUI Exclude list: Create or open a backup task and enter the following in the Exclude List field:
or if there are different patterns, you can combine the exclude and include filters as follows:
where the preceding + defines the include filter, while the pattern without the plus (+) defines the exclude filter.
|Regex mandates that every pattern is followed by a comma.
Alternatively, to create the include filter and include only those items that match the defined pattern (via the regular expression) using the SBC CLI, enter the command sbc -b with the -x (exclude regex) parameter (for the exclude list), followed by + at the beginning of the specified pattern, as shown in the following example:
sbc -b -s @/dev/null -v 1 -x '+xxx.*' /tmp/test-regex/1/
- For more details on using regular expressions, see Examples for Excluding Matched Patterns.
- For more details on exclude lists, see Creating Exclude List.
Linux sparse files support
A sparse file is a file that allows optimization of disk usage – efficient storage allocation for large data where much of the data is zeros (empty data). These zeros are not stored as zeros on disk, instead brief information (metadata) is written representing the empty blocks to disk rather than the actual "empty" space. With sparse files, the logical file size is larger than the physical file size as the zeros are not physically stored on a storage device.
Handling sparse files
With SEP sesam support for sparse files, these files are marked as sparse in the cpio stream and backed up completely. When restoring, the file marked as sparse is created as a sparse by default, with zero ranges created as sparse ranges and no additional option required for this. The file is processed in 512-byte blocks and only if such a block consists entirely of zero bytes (0x00) is that block created sparse (hole).
In this way, SEP sesam ensures that when restoring a sparse file that contains large zero ranges, the physical disk space occupied is not significantly different from that of the original file, often even less. The concern that the disk may not be large enough to restore a sparse file and that the restore process will consequently fail, is thus unneeded. Especially when restoring a complete volume, support for sparse files prevents running out of disk space.
Sparse files are backed up completely by default, but marked as sparse in the cpio stream. When restoring, the zero ranges (>= 512 bytes) are created as sparse areas.
Note that some file systems create sparse files only with larger blocks, e.g. only with 4KByte, i.e. only contiguous areas with at least 4KByte are created sparse.
You can use additional options to ignore the sparse property during backup and restore. Note that the behaviour of the -o sparse=no is different for backup and restore.
- -o sparse=no
- The 'sparse' flag in the cpio stream is not set for sparse files, so when restoring with the default option (==: -o sparse=origin) zero ranges of sparse files are written completely.
- -o sparse=no
- The 'sparse' flag in the cpio stream is ignored, zero ranges are written completely to the file.
- -o sparse=zero
- In the case of a file with zero ranges, these ranges are created as sparse ranges, regardless of whether the file was already 'sparse' before.
|The option '-o sparse=origin' sets the default behaviour, so it must not be set explicitly.
Support for Linux O_NOATIME option to prevent updating last access time
SEP sesam v. ≥ 220.127.116.11 Jaglion V2 supports the O_NOATIME file open command flag to avoid updating the access time (ATIME) when a file is opened or a directory is accessed. During backup, the access time attribute changes each time a file or directory is accessed (opened, read or locked). By using the O_NOATIME option, you disable the access time update, which makes reading a file and backup faster by reducing the metadawrites.
The man page for the open(2) command defines the O_NOATIME option as follows:
O_NOATIME (since Linux 2.6.8) Do not update the file last access time (st_atime in the inode) when the file is read(2).
This flag is intended for indexing or backup programs where it can significantly reduce disk activity. This flag may not be effective on all filesystems. For details, see open(2) — Linux manual page.
|O_NOATIME is granted only to the root (superuser) or the user who owns the file.